+++ /dev/null
-<?xml version="1.0" encoding="utf-8"?>
-<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
- "/usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd">
-<book>
- <title>The Altus Metrum System</title>
- <subtitle>An Owner's Manual for Altus Metrum Rocketry Electronics</subtitle>
- <bookinfo>
- <author>
- <firstname>Bdale</firstname>
- <surname>Garbee</surname>
- </author>
- <author>
- <firstname>Keith</firstname>
- <surname>Packard</surname>
- </author>
- <author>
- <firstname>Bob</firstname>
- <surname>Finch</surname>
- </author>
- <author>
- <firstname>Anthony</firstname>
- <surname>Towns</surname>
- </author>
- <copyright>
- <year>2015</year>
- <holder>Bdale Garbee and Keith Packard</holder>
- </copyright>
- <mediaobject>
- <imageobject>
- <imagedata fileref="../themes/background.png" width="6.0in"/>
- </imageobject>
- </mediaobject>
- <legalnotice>
- <para>
- This document is released under the terms of the
- <ulink url="http://creativecommons.org/licenses/by-sa/3.0/">
- Creative Commons ShareAlike 3.0
- </ulink>
- license.
- </para>
- </legalnotice>
- <revhistory>
- <revision>
- <revnumber>1.6.1</revnumber>
- <date>15 July 2015</date>
- <revremark>
- Minor release adding TeleBT v3.0 support.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.6</revnumber>
- <date>8 January 2015</date>
- <revremark>
- Major release adding TeleDongle v3.0 support.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.5</revnumber>
- <date>6 September 2014</date>
- <revremark>
- Major release adding EasyMega support.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.4.1</revnumber>
- <date>20 June 2014</date>
- <revremark>
- Minor release fixing some installation bugs.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.4</revnumber>
- <date>15 June 2014</date>
- <revremark>
- Major release adding TeleGPS support.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.3.2</revnumber>
- <date>24 January 2014</date>
- <revremark>
- Bug fixes for TeleMega and AltosUI.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.3.1</revnumber>
- <date>21 January 2014</date>
- <revremark>
- Bug fixes for TeleMega and TeleMetrum v2.0 along with a few
- small UI improvements.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.3</revnumber>
- <date>12 November 2013</date>
- <revremark>
- Updated for software version 1.3. Version 1.3 adds support
- for TeleMega, TeleMetrum v2.0, TeleMini v2.0 and EasyMini
- and fixes bugs in AltosUI and the AltOS firmware.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.2.1</revnumber>
- <date>21 May 2013</date>
- <revremark>
- Updated for software version 1.2. Version 1.2 adds support
- for TeleBT and AltosDroid. It also adds a few minor features
- and fixes bugs in AltosUI and the AltOS firmware.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.2</revnumber>
- <date>18 April 2013</date>
- <revremark>
- Updated for software version 1.2. Version 1.2 adds support
- for MicroPeak and the MicroPeak USB interface.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.1.1</revnumber>
- <date>16 September 2012</date>
- <revremark>
- Updated for software version 1.1.1 Version 1.1.1 fixes a few
- bugs found in version 1.1.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.1</revnumber>
- <date>13 September 2012</date>
- <revremark>
- Updated for software version 1.1. Version 1.1 has new
- features but is otherwise compatible with version 1.0.
- </revremark>
- </revision>
- <revision>
- <revnumber>1.0</revnumber>
- <date>24 August 2011</date>
- <revremark>
- Updated for software version 1.0. Note that 1.0 represents a
- telemetry format change, meaning both ends of a link
- (TeleMetrum/TeleMini and TeleDongle) must be updated or
- communications will fail.
- </revremark>
- </revision>
- <revision>
- <revnumber>0.9</revnumber>
- <date>18 January 2011</date>
- <revremark>
- Updated for software version 0.9. Note that 0.9 represents a
- telemetry format change, meaning both ends of a link (TeleMetrum and
- TeleDongle) must be updated or communications will fail.
- </revremark>
- </revision>
- <revision>
- <revnumber>0.8</revnumber>
- <date>24 November 2010</date>
- <revremark>Updated for software version 0.8 </revremark>
- </revision>
- </revhistory>
- </bookinfo>
- <dedication>
- <title>Acknowledgments</title>
- <para>
- Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing “The
- Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter
- Kit” which formed the basis of the original Getting Started chapter
- in this manual. Bob was one of our first customers for a production
- TeleMetrum, and his continued enthusiasm and contributions
- are immensely gratifying and highly appreciated!
- </para>
- <para>
- And thanks to Anthony (AJ) Towns for major contributions including
- the AltosUI graphing and site map code and associated documentation.
- Free software means that our customers and friends can become our
- collaborators, and we certainly appreciate this level of
- contribution!
- </para>
- <para>
- Have fun using these products, and we hope to meet all of you
- out on the rocket flight line somewhere.
- <literallayout>
-Bdale Garbee, KB0G
-NAR #87103, TRA #12201
-
-Keith Packard, KD7SQG
-NAR #88757, TRA #12200
- </literallayout>
- </para>
- </dedication>
- <chapter>
- <title>Introduction and Overview</title>
- <para>
- Welcome to the Altus Metrum community! Our circuits and software reflect
- our passion for both hobby rocketry and Free Software. We hope their
- capabilities and performance will delight you in every way, but by
- releasing all of our hardware and software designs under open licenses,
- we also hope to empower you to take as active a role in our collective
- future as you wish!
- </para>
- <para>
- The first device created for our community was TeleMetrum, a dual
- deploy altimeter with fully integrated GPS and radio telemetry
- as standard features, and a “companion interface” that will
- support optional capabilities in the future. The latest version
- of TeleMetrum, v2.0, has all of the same features but with
- improved sensors and radio to offer increased performance.
- </para>
- <para>
- Our second device was TeleMini, a dual deploy altimeter with
- radio telemetry and radio direction finding. The first version
- of this device was only 13mm by 38mm (½ inch by 1½ inches) and
- could fit easily in an 18mm air-frame. The latest version, v2.0,
- includes a beeper, USB data download and extended on-board
- flight logging, along with an improved barometric sensor.
- </para>
- <para>
- TeleMega is our most sophisticated device, including six pyro
- channels (four of which are fully programmable), integrated GPS,
- integrated gyroscopes for staging/air-start inhibit and high
- performance telemetry.
- </para>
- <para>
- EasyMini is a dual-deploy altimeter with logging and built-in
- USB data download.
- </para>
- <para>
- EasyMega is essentially a TeleMega board with the GPS receiver
- and telemetry transmitter removed. It offers the same 6 pyro
- channels and integrated gyroscopes for staging/air-start inhibit.
- </para>
- <para>
- TeleDongle v0.2 was our first ground station, providing a USB to RF
- interfaces for communicating with the altimeters. Combined with
- your choice of antenna and notebook computer, TeleDongle and our
- associated user interface software form a complete ground
- station capable of logging and displaying in-flight telemetry,
- aiding rocket recovery, then processing and archiving flight
- data for analysis and review. The latest version, TeleDongle
- v3, has all new electronics with a higher performance radio
- for improved range.
- </para>
- <para>
- For a slightly more portable ground station experience that also
- provides direct rocket recovery support, TeleBT offers flight
- monitoring and data logging using a Bluetooth™ connection between
- the receiver and an Android device that has the AltosDroid
- application installed from the Google Play store.
- </para>
- <para>
- More products will be added to the Altus Metrum family over time, and
- we currently envision that this will be a single, comprehensive manual
- for the entire product family.
- </para>
- </chapter>
- <chapter>
- <title>Getting Started</title>
- <para>
- The first thing to do after you check the inventory of parts in your
- “starter kit” is to charge the battery.
- </para>
- <para>
- For TeleMetrum, TeleMega and EasyMega, the battery can be charged by plugging it into the
- corresponding socket of the device and then using the USB
- cable to plug the flight computer into your computer's USB socket. The
- on-board circuitry will charge the battery whenever it is plugged
- in, because the on-off switch does NOT control the
- charging circuitry.
- </para>
- <para>
- On TeleMetrum v1 boards, when the GPS chip is initially
- searching for satellites, TeleMetrum will consume more current
- than it pulls from the USB port, so the battery must be
- attached in order to get satellite lock. Once GPS is locked,
- the current consumption goes back down enough to enable charging
- while running. So it's a good idea to fully charge the battery
- as your first item of business so there is no issue getting and
- maintaining satellite lock. The yellow charge indicator led
- will go out when the battery is nearly full and the charger goes
- to trickle charge. It can take several hours to fully recharge a
- deeply discharged battery.
- </para>
- <para>
- TeleMetrum v2.0, TeleMega and EasyMega use a higher power battery charger,
- allowing them to charge the battery while running the board at
- maximum power. When the battery is charging, or when the board
- is consuming a lot of power, the red LED will be lit. When the
- battery is fully charged, the green LED will be lit. When the
- battery is damaged or missing, both LEDs will be lit, which
- appears yellow.
- </para>
- <para>
- The Lithium Polymer TeleMini and EasyMini battery can be charged by
- disconnecting it from the board and plugging it into a
- standalone battery charger such as the LipoCharger product
- included in TeleMini Starter Kits, and connecting that via a USB
- cable to a laptop or other USB power source.
- </para>
- <para>
- You can also choose to use another battery with TeleMini v2.0
- and EasyMini, anything supplying between 4 and 12 volts should
- work fine (like a standard 9V battery), but if you are planning
- to fire pyro charges, ground testing is required to verify that
- the battery supplies enough current to fire your chosen e-matches.
- </para>
- <para>
- The other active device in the starter kit is the TeleDongle USB to
- RF interface. If you plug it in to your Mac or Linux computer it should
- “just work”, showing up as a serial port device. Windows systems need
- driver information that is part of the AltOS download to know that the
- existing USB modem driver will work. We therefore recommend installing
- our software before plugging in TeleDongle if you are using a Windows
- computer. If you are using an older version of Linux and are having
- problems, try moving to a fresher kernel (2.6.33 or newer).
- </para>
- <para>
- Next you should obtain and install the AltOS software. The AltOS
- distribution includes the AltosUI ground station program, current
- firmware
- images for all of the hardware, and a number of standalone
- utilities that are rarely needed. Pre-built binary packages are
- available for Linux, Microsoft Windows, and recent MacOSX
- versions. Full source code and build instructions are also
- available. The latest version may always be downloaded from
- <ulink url="http://altusmetrum.org/AltOS"/>.
- </para>
- <para>
- If you're using a TeleBT instead of the TeleDongle, you'll want to
- install the AltosDroid application from the Google Play store on an
- Android device. You don't need a data plan to use AltosDroid, but
- without network access, the Map view will be less useful as it
- won't contain any map data. You can also use TeleBT connected
- over USB with your laptop computer; it acts exactly like a
- TeleDongle. Anywhere this manual talks about TeleDongle, you can
- also read that as 'and TeleBT when connected via USB'.
- </para>
- </chapter>
- <chapter>
- <title>Handling Precautions</title>
- <para>
- All Altus Metrum products are sophisticated electronic devices.
- When handled gently and properly installed in an air-frame, they
- will deliver impressive results. However, as with all electronic
- devices, there are some precautions you must take.
- </para>
- <para>
- The Lithium Polymer rechargeable batteries have an
- extraordinary power density. This is great because we can fly with
- much less battery mass than if we used alkaline batteries or previous
- generation rechargeable batteries... but if they are punctured
- or their leads are allowed to short, they can and will release their
- energy very rapidly!
- Thus we recommend that you take some care when handling our batteries
- and consider giving them some extra protection in your air-frame. We
- often wrap them in suitable scraps of closed-cell packing foam before
- strapping them down, for example.
- </para>
- <para>
- The barometric sensors used on all of our flight computers are
- sensitive to sunlight. In normal mounting situations, the baro sensor
- and all of the other surface mount components
- are “down” towards whatever the underlying mounting surface is, so
- this is not normally a problem. Please consider this when designing an
- installation in an air-frame with a see-through plastic payload bay. It
- is particularly important to
- consider this with TeleMini v1.0, both because the baro sensor is on the
- “top” of the board, and because many model rockets with payload bays
- use clear plastic for the payload bay! Replacing these with an opaque
- cardboard tube, painting them, or wrapping them with a layer of masking
- tape are all reasonable approaches to keep the sensor out of direct
- sunlight.
- </para>
- <para>
- The barometric sensor sampling port must be able to “breathe”,
- both by not being covered by foam or tape or other materials that might
- directly block the hole on the top of the sensor, and also by having a
- suitable static vent to outside air.
- </para>
- <para>
- As with all other rocketry electronics, Altus Metrum altimeters must
- be protected from exposure to corrosive motor exhaust and ejection
- charge gasses.
- </para>
- </chapter>
- <chapter>
- <title>Altus Metrum Hardware</title>
- <section>
- <title>General Usage Instructions</title>
- <para>
- Here are general instructions for hooking up an Altus Metrum
- flight computer. Instructions specific to each model will be
- found in the section devoted to that model below.
- </para>
- <para>
- To prevent electrical interference from affecting the
- operation of the flight computer, it's important to always
- twist pairs of wires connected to the board. Twist the switch
- leads, the pyro leads and the battery leads. This reduces
- interference through a mechanism called common mode rejection.
- </para>
- <section>
- <title>Hooking Up Lithium Polymer Batteries</title>
- <para>
- All Altus Metrum flight computers have a two pin JST PH
- series connector to connect up a single-cell Lithium Polymer
- cell (3.7V nominal). You can purchase matching batteries
- from the Altus Metrum store, or other vendors, or you can
- make your own. Pin 1 of the connector is positive, pin 2 is
- negative. Spark Fun sells a cable with the connector
- attached, which they call a <ulink
- url="https://www.sparkfun.com/products/9914">JST Jumper 2
- Wire Assembly</ulink>.
- </para>
- <para>
- Many RC vendors also sell lithium polymer batteries with
- this same connector. All that we have found use the opposite
- polarity, and if you use them that way, you will damage or
- destroy the flight computer.
- </para>
- </section>
- <section>
- <title>Hooking Up Pyro Charges</title>
- <para>
- Altus Metrum flight computers always have two screws for
- each pyro charge. This means you shouldn't need to put two
- wires into a screw terminal or connect leads from pyro
- charges together externally.
- </para>
- <para>
- On the flight computer, one lead from each charge is hooked
- to the positive battery terminal through the power switch.
- The other lead is connected through the pyro circuit, which
- is connected to the negative battery terminal when the pyro
- circuit is fired.
- </para>
- </section>
- <section>
- <title>Hooking Up a Power Switch</title>
- <para>
- Altus Metrum flight computers need an external power switch
- to turn them on. This disconnects both the computer and the
- pyro charges from the battery, preventing the charges from
- firing when in the Off position. The switch is in-line with
- the positive battery terminal.
- </para>
- <section>
- <title>Using an External Active Switch Circuit</title>
- <para>
- You can use an active switch circuit, such as the
- Featherweight Magnetic Switch, with any Altus Metrum
- flight computer. These require three connections, one to
- the battery, one to the positive power input on the flight
- computer and one to ground. Find instructions on how to
- hook these up for each flight computer below. The follow
- the instructions that come with your active switch to
- connect it up.
- </para>
- </section>
- </section>
- <section>
- <title>Using a Separate Pyro Battery</title>
- <para>
- As mentioned above in the section on hooking up pyro
- charges, one lead for each of the pyro charges is connected
- through the power switch directly to the positive battery
- terminal. The other lead is connected to the pyro circuit,
- which connects it to the negative battery terminal when the
- pyro circuit is fired. The pyro circuit on all of the flight
- computers is designed to handle up to 16V.
- </para>
- <para>
- To use a separate pyro battery, connect the negative pyro
- battery terminal to the flight computer ground terminal,
- the positive battery terminal to the igniter and the other
- igniter lead to the negative pyro terminal on the flight
- computer. When the pyro channel fires, it will complete the
- circuit between the negative pyro terminal and the ground
- terminal, firing the igniter. Specific instructions on how
- to hook this up will be found in each section below.
- </para>
- </section>
- <section>
- <title>Using a Different Kind of Battery</title>
- <para>
- EasyMini and TeleMini v2 are designed to use either a
- lithium polymer battery or any other battery producing
- between 4 and 12 volts, such as a rectangular 9V
- battery. TeleMega, EasyMega and TeleMetrum are not designed for this,
- and must only be powered by a lithium polymer battery. Find
- instructions on how to use other batteries in the EasyMini
- and TeleMini sections below.
- </para>
- </section>
- </section>
- <section>
- <title>Specifications</title>
- <para>
- Here's the full set of Altus Metrum products, both in
- production and retired.
- </para>
- <table frame='all'>
- <title>Altus Metrum Electronics</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='8' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Device'/>
- <colspec align='center' colwidth='*' colname='Barometer'/>
- <colspec align='center' colwidth='*' colname='Z-axis accelerometer'/>
- <colspec align='center' colwidth='*' colname='GPS'/>
- <colspec align='center' colwidth='*' colname='3D sensors'/>
- <colspec align='center' colwidth='*' colname='Storage'/>
- <colspec align='center' colwidth='*' colname='RF'/>
- <colspec align='center' colwidth='*' colname='Battery'/>
- <thead>
- <row>
- <entry align='center'>Device</entry>
- <entry align='center'>Barometer</entry>
- <entry align='center'>Z-axis accelerometer</entry>
- <entry align='center'>GPS</entry>
- <entry align='center'>3D sensors</entry>
- <entry align='center'>Storage</entry>
- <entry align='center'>RF Output</entry>
- <entry align='center'>Battery</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>TeleMetrum v1.0</entry>
- <entry><para>MP3H6115 10km (33k')</para></entry>
- <entry><para>MMA2202 50g</para></entry>
- <entry>SkyTraq</entry>
- <entry>-</entry>
- <entry>1MB</entry>
- <entry>10mW</entry>
- <entry>3.7V</entry>
- </row>
- <row>
- <entry>TeleMetrum v1.1</entry>
- <entry><para>MP3H6115 10km (33k')</para></entry>
- <entry><para>MMA2202 50g</para></entry>
- <entry>SkyTraq</entry>
- <entry>-</entry>
- <entry>2MB</entry>
- <entry>10mW</entry>
- <entry>3.7V</entry>
- </row>
- <row>
- <entry>TeleMetrum v1.2</entry>
- <entry><para>MP3H6115 10km (33k')</para></entry>
- <entry><para>ADXL78 70g</para></entry>
- <entry>SkyTraq</entry>
- <entry>-</entry>
- <entry>2MB</entry>
- <entry>10mW</entry>
- <entry>3.7V</entry>
- </row>
- <row>
- <entry>TeleMetrum v2.0</entry>
- <entry><para>MS5607 30km (100k')</para></entry>
- <entry><para>MMA6555 102g</para></entry>
- <entry>uBlox Max-7Q</entry>
- <entry>-</entry>
- <entry>8MB</entry>
- <entry>40mW</entry>
- <entry>3.7V</entry>
- </row>
- <row>
- <entry><para>TeleMini <?linebreak?>v1.0</para></entry>
- <entry><para>MP3H6115 10km (33k')</para></entry>
- <entry>-</entry>
- <entry>-</entry>
- <entry>-</entry>
- <entry>5kB</entry>
- <entry>10mW</entry>
- <entry>3.7V</entry>
- </row>
- <row>
- <entry>TeleMini <?linebreak?>v2.0</entry>
- <entry><para>MS5607 30km (100k')</para></entry>
- <entry>-</entry>
- <entry>-</entry>
- <entry>-</entry>
- <entry>1MB</entry>
- <entry>10mW</entry>
- <entry>3.7-12V</entry>
- </row>
- <row>
- <entry>EasyMini <?linebreak?>v1.0</entry>
- <entry><para>MS5607 30km (100k')</para></entry>
- <entry>-</entry>
- <entry>-</entry>
- <entry>-</entry>
- <entry>1MB</entry>
- <entry>-</entry>
- <entry>3.7-12V</entry>
- </row>
- <row>
- <entry>TeleMega <?linebreak?>v1.0</entry>
- <entry><para>MS5607 30km (100k')</para></entry>
- <entry><para>MMA6555 102g</para></entry>
- <entry>uBlox Max-7Q</entry>
- <entry><para>MPU6000 HMC5883</para></entry>
- <entry>8MB</entry>
- <entry>40mW</entry>
- <entry>3.7V</entry>
- </row>
- <row>
- <entry>EasyMega <?linebreak?>v1.0</entry>
- <entry><para>MS5607 30km (100k')</para></entry>
- <entry><para>MMA6555 102g</para></entry>
- <entry>-</entry>
- <entry><para>MPU6000 HMC5883</para></entry>
- <entry>8MB</entry>
- <entry>-</entry>
- <entry>3.7V</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- <table frame='all'>
- <title>Altus Metrum Boards</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='6' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Device'/>
- <colspec align='center' colwidth='*' colname='Connectors'/>
- <colspec align='center' colwidth='*' colname='Screw Terminals'/>
- <colspec align='center' colwidth='*' colname='Width'/>
- <colspec align='center' colwidth='*' colname='Length'/>
- <colspec align='center' colwidth='*' colname='Tube Size'/>
- <thead>
- <row>
- <entry align='center'>Device</entry>
- <entry align='center'>Connectors</entry>
- <entry align='center'>Screw Terminals</entry>
- <entry align='center'>Width</entry>
- <entry align='center'>Length</entry>
- <entry align='center'>Tube Size</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>TeleMetrum</entry>
- <entry><para>
- Antenna<?linebreak?>
- Debug<?linebreak?>
- Companion<?linebreak?>
- USB<?linebreak?>
- Battery
- </para></entry>
- <entry><para>Apogee pyro <?linebreak?>Main pyro <?linebreak?>Switch</para></entry>
- <entry>1 inch (2.54cm)</entry>
- <entry>2 ¾ inch (6.99cm)</entry>
- <entry>29mm coupler</entry>
- </row>
- <row>
- <entry><para>TeleMini <?linebreak?>v1.0</para></entry>
- <entry><para>
- Antenna<?linebreak?>
- Debug<?linebreak?>
- Battery
- </para></entry>
- <entry><para>
- Apogee pyro <?linebreak?>
- Main pyro
- </para></entry>
- <entry>½ inch (1.27cm)</entry>
- <entry>1½ inch (3.81cm)</entry>
- <entry>18mm coupler</entry>
- </row>
- <row>
- <entry>TeleMini <?linebreak?>v2.0</entry>
- <entry><para>
- Antenna<?linebreak?>
- Debug<?linebreak?>
- USB<?linebreak?>
- Battery
- </para></entry>
- <entry><para>
- Apogee pyro <?linebreak?>
- Main pyro <?linebreak?>
- Battery <?linebreak?>
- Switch
- </para></entry>
- <entry>0.8 inch (2.03cm)</entry>
- <entry>1½ inch (3.81cm)</entry>
- <entry>24mm coupler</entry>
- </row>
- <row>
- <entry>EasyMini</entry>
- <entry><para>
- Debug<?linebreak?>
- USB<?linebreak?>
- Battery
- </para></entry>
- <entry><para>
- Apogee pyro <?linebreak?>
- Main pyro <?linebreak?>
- Battery <?linebreak?>
- Switch
- </para></entry>
- <entry>0.8 inch (2.03cm)</entry>
- <entry>1½ inch (3.81cm)</entry>
- <entry>24mm coupler</entry>
- </row>
- <row>
- <entry>TeleMega</entry>
- <entry><para>
- Antenna<?linebreak?>
- Debug<?linebreak?>
- Companion<?linebreak?>
- USB<?linebreak?>
- Battery
- </para></entry>
- <entry><para>
- Apogee pyro <?linebreak?>
- Main pyro<?linebreak?>
- Pyro A-D<?linebreak?>
- Switch<?linebreak?>
- Pyro battery
- </para></entry>
- <entry>1¼ inch (3.18cm)</entry>
- <entry>3¼ inch (8.26cm)</entry>
- <entry>38mm coupler</entry>
- </row>
- <row>
- <entry>EasyMega</entry>
- <entry><para>
- Debug<?linebreak?>
- Companion<?linebreak?>
- USB<?linebreak?>
- Battery
- </para></entry>
- <entry><para>
- Apogee pyro <?linebreak?>
- Main pyro<?linebreak?>
- Pyro A-D<?linebreak?>
- Switch<?linebreak?>
- Pyro battery
- </para></entry>
- <entry>1¼ inch (3.18cm)</entry>
- <entry>2¼ inch (5.62cm)</entry>
- <entry>38mm coupler</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </section>
- <section>
- <title>TeleMetrum</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="telemetrum-v1.1-thside.jpg" width="5.5in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- TeleMetrum is a 1 inch by 2¾ inch circuit board. It was designed to
- fit inside coupler for 29mm air-frame tubing, but using it in a tube that
- small in diameter may require some creativity in mounting and wiring
- to succeed! The presence of an accelerometer means TeleMetrum should
- be aligned along the flight axis of the airframe, and by default the ¼
- wave UHF wire antenna should be on the nose-cone end of the board. The
- antenna wire is about 7 inches long, and wiring for a power switch and
- the e-matches for apogee and main ejection charges depart from the
- fin can end of the board, meaning an ideal “simple” avionics
- bay for TeleMetrum should have at least 10 inches of interior length.
- </para>
- <section>
- <title>TeleMetrum Screw Terminals</title>
- <para>
- TeleMetrum has six screw terminals on the end of the board
- opposite the telemetry antenna. Two are for the power
- switch, and two each for the apogee and main igniter
- circuits. Using the picture above and starting from the top,
- the terminals are as follows:
- </para>
- <table frame='all'>
- <title>TeleMetrum Screw Terminals</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='3' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Pin #'/>
- <colspec align='center' colwidth='2*' colname='Pin Name'/>
- <colspec align='left' colwidth='5*' colname='Description'/>
- <thead>
- <row>
- <entry align='center'>Terminal #</entry>
- <entry align='center'>Terminal Name</entry>
- <entry align='center'>Description</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>1</entry>
- <entry>Switch Output</entry>
- <entry>Switch connection to flight computer</entry>
- </row>
- <row>
- <entry>2</entry>
- <entry>Switch Input</entry>
- <entry>Switch connection to positive battery terminal</entry>
- </row>
- <row>
- <entry>3</entry>
- <entry>Main +</entry>
- <entry>Main pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>4</entry>
- <entry>Main -</entry>
- <entry>Main pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>5</entry>
- <entry>Apogee +</entry>
- <entry>Apogee pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>6</entry>
- <entry>Apogee -</entry>
- <entry>Apogee pyro channel connection to pyro circuit</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </section>
- <section>
- <title>Using a Separate Pyro Battery with TeleMetrum</title>
- <para>
- As described above, using an external pyro battery involves
- connecting the negative battery terminal to the flight
- computer ground, connecting the positive battery terminal to
- one of the igniter leads and connecting the other igniter
- lead to the per-channel pyro circuit connection.
- </para>
- <para>
- To connect the negative battery terminal to the TeleMetrum
- ground, insert a small piece of wire, 24 to 28 gauge
- stranded, into the GND hole just above the screw terminal
- strip and solder it in place.
- </para>
- <para>
- Connecting the positive battery terminal to the pyro
- charges must be done separate from TeleMetrum, by soldering
- them together or using some other connector.
- </para>
- <para>
- The other lead from each pyro charge is then inserted into
- the appropriate per-pyro channel screw terminal (terminal 4 for the
- Main charge, terminal 6 for the Apogee charge).
- </para>
- </section>
- <section>
- <title>Using an Active Switch with TeleMetrum</title>
- <para>
- As explained above, an external active switch requires three
- connections, one to the positive battery terminal, one to
- the flight computer positive input and one to ground.
- </para>
- <para>
- The positive battery terminal is available on screw terminal
- 2, the positive flight computer input is on terminal 1. To
- hook a lead to ground, solder a piece of wire, 24 to 28
- gauge stranded, to the GND hole just above terminal 1.
- </para>
- </section>
- </section>
- <section>
- <title>TeleMini v1.0</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="telemini-v1-top.jpg" width="5.5in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- TeleMini v1.0 is ½ inches by 1½ inches. It was
- designed to fit inside an 18mm air-frame tube, but using it in
- a tube that small in diameter may require some creativity in
- mounting and wiring to succeed! Since there is no
- accelerometer, TeleMini can be mounted in any convenient
- orientation. The default ¼ wave UHF wire antenna attached to
- the center of one end of the board is about 7 inches long. Two
- wires for the power switch are connected to holes in the
- middle of the board. Screw terminals for the e-matches for
- apogee and main ejection charges depart from the other end of
- the board, meaning an ideal “simple” avionics bay for TeleMini
- should have at least 9 inches of interior length.
- </para>
- <section>
- <title>TeleMini v1.0 Screw Terminals</title>
- <para>
- TeleMini v1.0 has four screw terminals on the end of the
- board opposite the telemetry antenna. Two are for the apogee
- and two are for main igniter circuits. There are also wires
- soldered to the board for the power switch. Using the
- picture above and starting from the top for the terminals
- and from the left for the power switch wires, the
- connections are as follows:
- </para>
- <table frame='all'>
- <title>TeleMini v1.0 Connections</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='3' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Pin #'/>
- <colspec align='center' colwidth='2*' colname='Pin Name'/>
- <colspec align='left' colwidth='5*' colname='Description'/>
- <thead>
- <row>
- <entry align='center'>Terminal #</entry>
- <entry align='center'>Terminal Name</entry>
- <entry align='center'>Description</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>1</entry>
- <entry>Apogee -</entry>
- <entry>Apogee pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>2</entry>
- <entry>Apogee +</entry>
- <entry>Apogee pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>3</entry>
- <entry>Main -</entry>
- <entry>Main pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>4</entry>
- <entry>Main +</entry>
- <entry>Main pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Left</entry>
- <entry>Switch Output</entry>
- <entry>Switch connection to flight computer</entry>
- </row>
- <row>
- <entry>Right</entry>
- <entry>Switch Input</entry>
- <entry>Switch connection to positive battery terminal</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </section>
- <section>
- <title>Using a Separate Pyro Battery with TeleMini v1.0</title>
- <para>
- As described above, using an external pyro battery involves
- connecting the negative battery terminal to the flight
- computer ground, connecting the positive battery terminal to
- one of the igniter leads and connecting the other igniter
- lead to the per-channel pyro circuit connection. Because
- there is no solid ground connection to use on TeleMini, this
- is not recommended.
- </para>
- <para>
- The only available ground connection on TeleMini v1.0 are
- the two mounting holes next to the telemetry
- antenna. Somehow connect a small piece of wire to one of
- those holes and hook it to the negative pyro battery terminal.
- </para>
- <para>
- Connecting the positive battery terminal to the pyro
- charges must be done separate from TeleMini v1.0, by soldering
- them together or using some other connector.
- </para>
- <para>
- The other lead from each pyro charge is then inserted into
- the appropriate per-pyro channel screw terminal (terminal 3 for the
- Main charge, terminal 1 for the Apogee charge).
- </para>
- </section>
- <section>
- <title>Using an Active Switch with TeleMini v1.0</title>
- <para>
- As explained above, an external active switch requires three
- connections, one to the positive battery terminal, one to
- the flight computer positive input and one to ground. Again,
- because TeleMini doesn't have any good ground connection,
- this is not recommended.
- </para>
- <para>
- The positive battery terminal is available on the Right
- power switch wire, the positive flight computer input is on
- the left power switch wire. Hook a lead to either of the
- mounting holes for a ground connection.
- </para>
- </section>
- </section>
- <section>
- <title>TeleMini v2.0</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="telemini-v2-top.jpg" width="5.5in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- TeleMini v2.0 is 0.8 inches by 1½ inches. It adds more
- on-board data logging memory, a built-in USB connector and
- screw terminals for the battery and power switch. The larger
- board fits in a 24mm coupler. There's also a battery connector
- for a LiPo battery if you want to use one of those.
- </para>
- <section>
- <title>TeleMini v2.0 Screw Terminals</title>
- <para>
- TeleMini v2.0 has two sets of four screw terminals on the end of the
- board opposite the telemetry antenna. Using the picture
- above, the top four have connections for the main pyro
- circuit and an external battery and the bottom four have
- connections for the apogee pyro circuit and the power
- switch. Counting from the left, the connections are as follows:
- </para>
- <table frame='all'>
- <title>TeleMini v2.0 Connections</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='3' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Pin #'/>
- <colspec align='center' colwidth='2*' colname='Pin Name'/>
- <colspec align='left' colwidth='5*' colname='Description'/>
- <thead>
- <row>
- <entry align='center'>Terminal #</entry>
- <entry align='center'>Terminal Name</entry>
- <entry align='center'>Description</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>Top 1</entry>
- <entry>Main -</entry>
- <entry>Main pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Top 2</entry>
- <entry>Main +</entry>
- <entry>Main pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Top 3</entry>
- <entry>Battery +</entry>
- <entry>Positive external battery terminal</entry>
- </row>
- <row>
- <entry>Top 4</entry>
- <entry>Battery -</entry>
- <entry>Negative external battery terminal</entry>
- </row>
- <row>
- <entry>Bottom 1</entry>
- <entry>Apogee -</entry>
- <entry>Apogee pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Bottom 2</entry>
- <entry>Apogee +</entry>
- <entry>Apogee pyro channel common connection to
- battery +</entry>
- </row>
- <row>
- <entry>Bottom 3</entry>
- <entry>Switch Output</entry>
- <entry>Switch connection to flight computer</entry>
- </row>
- <row>
- <entry>Bottom 4</entry>
- <entry>Switch Input</entry>
- <entry>Switch connection to positive battery terminal</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </section>
- <section>
- <title>Using a Separate Pyro Battery with TeleMini v2.0</title>
- <para>
- As described above, using an external pyro battery involves
- connecting the negative battery terminal to the flight
- computer ground, connecting the positive battery terminal to
- one of the igniter leads and connecting the other igniter
- lead to the per-channel pyro circuit connection.
- </para>
- <para>
- To connect the negative pyro battery terminal to TeleMini
- ground, connect it to the negative external battery
- connection, top terminal 4.
- </para>
- <para>
- Connecting the positive battery terminal to the pyro
- charges must be done separate from TeleMini v2.0, by soldering
- them together or using some other connector.
- </para>
- <para>
- The other lead from each pyro charge is then inserted into
- the appropriate per-pyro channel screw terminal (top
- terminal 1 for the Main charge, bottom terminal 1 for the
- Apogee charge).
- </para>
- </section>
- <section>
- <title>Using an Active Switch with TeleMini v2.0</title>
- <para>
- As explained above, an external active switch requires three
- connections, one to the positive battery terminal, one to
- the flight computer positive input and one to ground. Use
- the negative external battery connection, top terminal 4 for
- ground.
- </para>
- <para>
- The positive battery terminal is available on bottom
- terminal 4, the positive flight computer input is on the
- bottom terminal 3.
- </para>
- </section>
- </section>
- <section>
- <title>EasyMini</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="easymini-top.jpg" width="5.5in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- EasyMini is built on a 0.8 inch by 1½ inch circuit board. It's
- designed to fit in a 24mm coupler tube. The connectors and
- screw terminals match TeleMini v2.0, so you can easily swap between
- EasyMini and TeleMini.
- </para>
- <section>
- <title>EasyMini Screw Terminals</title>
- <para>
- EasyMini has two sets of four screw terminals on the end of the
- board opposite the telemetry antenna. Using the picture
- above, the top four have connections for the main pyro
- circuit and an external battery and the bottom four have
- connections for the apogee pyro circuit and the power
- switch. Counting from the left, the connections are as follows:
- </para>
- <table frame='all'>
- <title>EasyMini Connections</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='3' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Pin #'/>
- <colspec align='center' colwidth='2*' colname='Pin Name'/>
- <colspec align='left' colwidth='5*' colname='Description'/>
- <thead>
- <row>
- <entry align='center'>Terminal #</entry>
- <entry align='center'>Terminal Name</entry>
- <entry align='center'>Description</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>Top 1</entry>
- <entry>Main -</entry>
- <entry>Main pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Top 2</entry>
- <entry>Main +</entry>
- <entry>Main pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Top 3</entry>
- <entry>Battery +</entry>
- <entry>Positive external battery terminal</entry>
- </row>
- <row>
- <entry>Top 4</entry>
- <entry>Battery -</entry>
- <entry>Negative external battery terminal</entry>
- </row>
- <row>
- <entry>Bottom 1</entry>
- <entry>Apogee -</entry>
- <entry>Apogee pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Bottom 2</entry>
- <entry>Apogee +</entry>
- <entry>Apogee pyro channel common connection to
- battery +</entry>
- </row>
- <row>
- <entry>Bottom 3</entry>
- <entry>Switch Output</entry>
- <entry>Switch connection to flight computer</entry>
- </row>
- <row>
- <entry>Bottom 4</entry>
- <entry>Switch Input</entry>
- <entry>Switch connection to positive battery terminal</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </section>
- <section>
- <title>Using a Separate Pyro Battery with EasyMini</title>
- <para>
- As described above, using an external pyro battery involves
- connecting the negative battery terminal to the flight
- computer ground, connecting the positive battery terminal to
- one of the igniter leads and connecting the other igniter
- lead to the per-channel pyro circuit connection.
- </para>
- <para>
- To connect the negative pyro battery terminal to TeleMini
- ground, connect it to the negative external battery
- connection, top terminal 4.
- </para>
- <para>
- Connecting the positive battery terminal to the pyro
- charges must be done separate from EasyMini, by soldering
- them together or using some other connector.
- </para>
- <para>
- The other lead from each pyro charge is then inserted into
- the appropriate per-pyro channel screw terminal (top
- terminal 1 for the Main charge, bottom terminal 1 for the
- Apogee charge).
- </para>
- </section>
- <section>
- <title>Using an Active Switch with EasyMini</title>
- <para>
- As explained above, an external active switch requires three
- connections, one to the positive battery terminal, one to
- the flight computer positive input and one to ground. Use
- the negative external battery connection, top terminal 4 for
- ground.
- </para>
- <para>
- The positive battery terminal is available on bottom
- terminal 4, the positive flight computer input is on the
- bottom terminal 3.
- </para>
- </section>
- </section>
- <section>
- <title>TeleMega</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="telemega-v1.0-top.jpg" width="5.5in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- TeleMega is a 1¼ inch by 3¼ inch circuit board. It was
- designed to easily fit in a 38mm coupler. Like TeleMetrum,
- TeleMega has an accelerometer and so it must be mounted so that
- the board is aligned with the flight axis. It can be mounted
- either antenna up or down.
- </para>
- <section>
- <title>TeleMega Screw Terminals</title>
- <para>
- TeleMega has two sets of nine screw terminals on the end of
- the board opposite the telemetry antenna. They are as follows:
- </para>
- <table frame='all'>
- <title>TeleMega Screw Terminals</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='3' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Pin #'/>
- <colspec align='center' colwidth='2*' colname='Pin Name'/>
- <colspec align='left' colwidth='5*' colname='Description'/>
- <thead>
- <row>
- <entry align='center'>Terminal #</entry>
- <entry align='center'>Terminal Name</entry>
- <entry align='center'>Description</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>Top 1</entry>
- <entry>Switch Input</entry>
- <entry>Switch connection to positive battery terminal</entry>
- </row>
- <row>
- <entry>Top 2</entry>
- <entry>Switch Output</entry>
- <entry>Switch connection to flight computer</entry>
- </row>
- <row>
- <entry>Top 3</entry>
- <entry>GND</entry>
- <entry>Ground connection for use with external active switch</entry>
- </row>
- <row>
- <entry>Top 4</entry>
- <entry>Main -</entry>
- <entry>Main pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Top 5</entry>
- <entry>Main +</entry>
- <entry>Main pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Top 6</entry>
- <entry>Apogee -</entry>
- <entry>Apogee pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Top 7</entry>
- <entry>Apogee +</entry>
- <entry>Apogee pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Top 8</entry>
- <entry>D -</entry>
- <entry>D pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Top 9</entry>
- <entry>D +</entry>
- <entry>D pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Bottom 1</entry>
- <entry>GND</entry>
- <entry>Ground connection for negative pyro battery terminal</entry>
- </row>
- <row>
- <entry>Bottom 2</entry>
- <entry>Pyro</entry>
- <entry>Positive pyro battery terminal</entry>
- </row>
- <row>
- <entry>Bottom 3</entry>
- <entry>Lipo</entry>
- <entry>
- Power switch output. Use to connect main battery to
- pyro battery input
- </entry>
- </row>
- <row>
- <entry>Bottom 4</entry>
- <entry>A -</entry>
- <entry>A pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Bottom 5</entry>
- <entry>A +</entry>
- <entry>A pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Bottom 6</entry>
- <entry>B -</entry>
- <entry>B pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Bottom 7</entry>
- <entry>B +</entry>
- <entry>B pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Bottom 8</entry>
- <entry>C -</entry>
- <entry>C pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Bottom 9</entry>
- <entry>C +</entry>
- <entry>C pyro channel common connection to battery +</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </section>
- <section>
- <title>Using a Separate Pyro Battery with TeleMega</title>
- <para>
- TeleMega provides explicit support for an external pyro
- battery. All that is required is to remove the jumper
- between the lipo terminal (Bottom 3) and the pyro terminal
- (Bottom 2). Then hook the negative pyro battery terminal to ground
- (Bottom 1) and the positive pyro battery to the pyro battery
- input (Bottom 2). You can then use the existing pyro screw
- terminals to hook up all of the pyro charges.
- </para>
- </section>
- <section>
- <title>Using Only One Battery With TeleMega</title>
- <para>
- Because TeleMega has built-in support for a separate pyro
- battery, if you want to fly with just one battery running
- both the computer and firing the charges, you need to
- connect the flight computer battery to the pyro
- circuit. TeleMega has two screw terminals for this—hook a
- wire from the Lipo terminal (Bottom 3) to the Pyro terminal
- (Bottom 2).
- </para>
- </section>
- <section>
- <title>Using an Active Switch with TeleMega</title>
- <para>
- As explained above, an external active switch requires three
- connections, one to the positive battery terminal, one to
- the flight computer positive input and one to ground.
- </para>
- <para>
- The positive battery terminal is available on Top terminal
- 1, the positive flight computer input is on Top terminal
- 2. Ground is on Top terminal 3.
- </para>
- </section>
- </section>
- <section>
- <title>EasyMega</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="easymega-v1.0-top.jpg" width="4.5in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- EasyMega is a 1¼ inch by 2¼ inch circuit board. It was
- designed to easily fit in a 38mm coupler. Like TeleMetrum,
- EasyMega has an accelerometer and so it must be mounted so that
- the board is aligned with the flight axis. It can be mounted
- either antenna up or down.
- </para>
- <section>
- <title>EasyMega Screw Terminals</title>
- <para>
- EasyMega has two sets of nine screw terminals on the end of
- the board opposite the telemetry antenna. They are as follows:
- </para>
- <table frame='all'>
- <title>EasyMega Screw Terminals</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='3' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Pin #'/>
- <colspec align='center' colwidth='2*' colname='Pin Name'/>
- <colspec align='left' colwidth='5*' colname='Description'/>
- <thead>
- <row>
- <entry align='center'>Terminal #</entry>
- <entry align='center'>Terminal Name</entry>
- <entry align='center'>Description</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>Top 1</entry>
- <entry>Switch Input</entry>
- <entry>Switch connection to positive battery terminal</entry>
- </row>
- <row>
- <entry>Top 2</entry>
- <entry>Switch Output</entry>
- <entry>Switch connection to flight computer</entry>
- </row>
- <row>
- <entry>Top 3</entry>
- <entry>GND</entry>
- <entry>Ground connection for use with external active switch</entry>
- </row>
- <row>
- <entry>Top 4</entry>
- <entry>Main -</entry>
- <entry>Main pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Top 5</entry>
- <entry>Main +</entry>
- <entry>Main pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Top 6</entry>
- <entry>Apogee -</entry>
- <entry>Apogee pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Top 7</entry>
- <entry>Apogee +</entry>
- <entry>Apogee pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Top 8</entry>
- <entry>D -</entry>
- <entry>D pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Top 9</entry>
- <entry>D +</entry>
- <entry>D pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Bottom 1</entry>
- <entry>GND</entry>
- <entry>Ground connection for negative pyro battery terminal</entry>
- </row>
- <row>
- <entry>Bottom 2</entry>
- <entry>Pyro</entry>
- <entry>Positive pyro battery terminal</entry>
- </row>
- <row>
- <entry>Bottom 3</entry>
- <entry>Lipo</entry>
- <entry>
- Power switch output. Use to connect main battery to
- pyro battery input
- </entry>
- </row>
- <row>
- <entry>Bottom 4</entry>
- <entry>A -</entry>
- <entry>A pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Bottom 5</entry>
- <entry>A +</entry>
- <entry>A pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Bottom 6</entry>
- <entry>B -</entry>
- <entry>B pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Bottom 7</entry>
- <entry>B +</entry>
- <entry>B pyro channel common connection to battery +</entry>
- </row>
- <row>
- <entry>Bottom 8</entry>
- <entry>C -</entry>
- <entry>C pyro channel connection to pyro circuit</entry>
- </row>
- <row>
- <entry>Bottom 9</entry>
- <entry>C +</entry>
- <entry>C pyro channel common connection to battery +</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </section>
- <section>
- <title>Using a Separate Pyro Battery with EasyMega</title>
- <para>
- EasyMega provides explicit support for an external pyro
- battery. All that is required is to remove the jumper
- between the lipo terminal (Bottom 3) and the pyro terminal
- (Bottom 2). Then hook the negative pyro battery terminal to ground
- (Bottom 1) and the positive pyro battery to the pyro battery
- input (Bottom 2). You can then use the existing pyro screw
- terminals to hook up all of the pyro charges.
- </para>
- </section>
- <section>
- <title>Using Only One Battery With EasyMega</title>
- <para>
- Because EasyMega has built-in support for a separate pyro
- battery, if you want to fly with just one battery running
- both the computer and firing the charges, you need to
- connect the flight computer battery to the pyro
- circuit. EasyMega has two screw terminals for this—hook a
- wire from the Lipo terminal (Bottom 3) to the Pyro terminal
- (Bottom 2).
- </para>
- </section>
- <section>
- <title>Using an Active Switch with EasyMega</title>
- <para>
- As explained above, an external active switch requires three
- connections, one to the positive battery terminal, one to
- the flight computer positive input and one to ground.
- </para>
- <para>
- The positive battery terminal is available on Top terminal
- 1, the positive flight computer input is on Top terminal
- 2. Ground is on Top terminal 3.
- </para>
- </section>
- </section>
- <section>
- <title>Flight Data Recording</title>
- <para>
- Each flight computer logs data at 100 samples per second
- during ascent and 10 samples per second during descent, except
- for TeleMini v1.0, which records ascent at 10 samples per
- second and descent at 1 sample per second. Data are logged to
- an on-board flash memory part, which can be partitioned into
- several equal-sized blocks, one for each flight.
- </para>
- <table frame='all'>
- <title>Data Storage on Altus Metrum altimeters</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='4' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Device'/>
- <colspec align='center' colwidth='*' colname='Bytes per sample'/>
- <colspec align='center' colwidth='*' colname='Total storage'/>
- <colspec align='center' colwidth='*' colname='Minutes of
- full-rate'/>
- <thead>
- <row>
- <entry align='center'>Device</entry>
- <entry align='center'>Bytes per Sample</entry>
- <entry align='center'>Total Storage</entry>
- <entry align='center'>Minutes at Full Rate</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>TeleMetrum v1.0</entry>
- <entry>8</entry>
- <entry>1MB</entry>
- <entry>20</entry>
- </row>
- <row>
- <entry>TeleMetrum v1.1 v1.2</entry>
- <entry>8</entry>
- <entry>2MB</entry>
- <entry>40</entry>
- </row>
- <row>
- <entry>TeleMetrum v2.0</entry>
- <entry>16</entry>
- <entry>8MB</entry>
- <entry>80</entry>
- </row>
- <row>
- <entry>TeleMini v1.0</entry>
- <entry>2</entry>
- <entry>5kB</entry>
- <entry>4</entry>
- </row>
- <row>
- <entry>TeleMini v2.0</entry>
- <entry>16</entry>
- <entry>1MB</entry>
- <entry>10</entry>
- </row>
- <row>
- <entry>EasyMini</entry>
- <entry>16</entry>
- <entry>1MB</entry>
- <entry>10</entry>
- </row>
- <row>
- <entry>TeleMega</entry>
- <entry>32</entry>
- <entry>8MB</entry>
- <entry>40</entry>
- </row>
- <row>
- <entry>EasyMega</entry>
- <entry>32</entry>
- <entry>8MB</entry>
- <entry>40</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- <para>
- The on-board flash is partitioned into separate flight logs,
- each of a fixed maximum size. Increase the maximum size of
- each log and you reduce the number of flights that can be
- stored. Decrease the size and you can store more flights.
- </para>
- <para>
- Configuration data is also stored in the flash memory on
- TeleMetrum v1.x, TeleMini and EasyMini. This consumes 64kB
- of flash space. This configuration space is not available
- for storing flight log data. TeleMetrum v2.0, TeleMega and EasyMega
- store configuration data in a bit of eeprom available within
- the processor chip, leaving that space available in flash for
- more flight data.
- </para>
- <para>
- To compute the amount of space needed for a single flight, you
- can multiply the expected ascent time (in seconds) by 100
- times bytes-per-sample, multiply the expected descent time (in
- seconds) by 10 times the bytes per sample and add the two
- together. That will slightly under-estimate the storage (in
- bytes) needed for the flight. For instance, a TeleMetrum v2.0 flight spending
- 20 seconds in ascent and 150 seconds in descent will take
- about (20 * 1600) + (150 * 160) = 56000 bytes of storage. You
- could store dozens of these flights in the on-board flash.
- </para>
- <para>
- The default size allows for several flights on each flight
- computer, except for TeleMini v1.0, which only holds data for a
- single flight. You can adjust the size.
- </para>
- <para>
- Altus Metrum flight computers will not overwrite existing
- flight data, so be sure to download flight data and erase it
- from the flight computer before it fills up. The flight
- computer will still successfully control the flight even if it
- cannot log data, so the only thing you will lose is the data.
- </para>
- </section>
- <section>
- <title>Installation</title>
- <para>
- A typical installation involves attaching
- only a suitable battery, a single pole switch for
- power on/off, and two pairs of wires connecting e-matches for the
- apogee and main ejection charges. All Altus Metrum products are
- designed for use with single-cell batteries with 3.7 volts
- nominal. TeleMini v2.0 and EasyMini may also be used with other
- batteries as long as they supply between 4 and 12 volts.
- </para>
- <para>
- The battery connectors are a standard 2-pin JST connector and
- match batteries sold by Spark Fun. These batteries are
- single-cell Lithium Polymer batteries that nominally provide 3.7
- volts. Other vendors sell similar batteries for RC aircraft
- using mating connectors, however the polarity for those is
- generally reversed from the batteries used by Altus Metrum
- products. In particular, the Tenergy batteries supplied for use
- in Featherweight flight computers are not compatible with Altus
- Metrum flight computers or battery chargers. <emphasis>Check
- polarity and voltage before connecting any battery not purchased
- from Altus Metrum or Spark Fun.</emphasis>
- </para>
- <para>
- By default, we use the unregulated output of the battery directly
- to fire ejection charges. This works marvelously with standard
- low-current e-matches like the J-Tek from MJG Technologies, and with
- Quest Q2G2 igniters. However, if you want or need to use a separate
- pyro battery, check out the “External Pyro Battery” section in this
- manual for instructions on how to wire that up. The altimeters are
- designed to work with an external pyro battery of no more than 15 volts.
- </para>
- <para>
- Ejection charges are wired directly to the screw terminal block
- at the aft end of the altimeter. You'll need a very small straight
- blade screwdriver for these screws, such as you might find in a
- jeweler's screwdriver set.
- </para>
- <para>
- Except for TeleMini v1.0, the flight computers also use the
- screw terminal block for the power switch leads. On TeleMini v1.0,
- the power switch leads are soldered directly to the board and
- can be connected directly to a switch.
- </para>
- <para>
- For most air-frames, the integrated antennas are more than
- adequate. However, if you are installing in a carbon-fiber or
- metal electronics bay which is opaque to RF signals, you may need to
- use off-board external antennas instead. In this case, you can
- replace the stock UHF antenna wire with an edge-launched SMA connector,
- and, on TeleMetrum v1, you can unplug the integrated GPS
- antenna and select an appropriate off-board GPS antenna with
- cable terminating in a U.FL connector.
- </para>
- </section>
- </chapter>
- <chapter>
- <title>System Operation</title>
- <section>
- <title>Firmware Modes </title>
- <para>
- The AltOS firmware build for the altimeters has two
- fundamental modes, “idle” and “flight”. Which of these modes
- the firmware operates in is determined at start up time. For
- TeleMetrum, TeleMega and EasyMega, which have accelerometers, the mode is
- controlled by the orientation of the
- rocket (well, actually the board, of course...) at the time
- power is switched on. If the rocket is “nose up”, then
- the flight computer assumes it's on a rail or rod being prepared for
- launch, so the firmware chooses flight mode. However, if the
- rocket is more or less horizontal, the firmware instead enters
- idle mode. Since TeleMini v2.0 and EasyMini don't have an
- accelerometer we can use to determine orientation, “idle” mode
- is selected if the board is connected via USB to a computer,
- otherwise the board enters “flight” mode. TeleMini v1.0
- selects “idle” mode if it receives a command packet within the
- first five seconds of operation.
- </para>
- <para>
- At power on, the altimeter will beep out the battery voltage
- to the nearest tenth of a volt. Each digit is represented by
- a sequence of short “dit” beeps, with a pause between
- digits. A zero digit is represented with one long “dah”
- beep. Then there will be a short pause while the altimeter
- completes initialization and self test, and decides which mode
- to enter next.
- </para>
- <para>
- Here's a short summary of all of the modes and the beeping (or
- flashing, in the case of TeleMini v1) that accompanies each
- mode. In the description of the beeping pattern, “dit” means a
- short beep while "dah" means a long beep (three times as
- long). “Brap” means a long dissonant tone.
- <table frame='all'>
- <title>AltOS Modes</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='4' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Mode Name'/>
- <colspec align='center' colwidth='*' colname='Letter'/>
- <colspec align='center' colwidth='*' colname='Beeps'/>
- <colspec align='center' colwidth='*' colname='Description'/>
- <thead>
- <row>
- <entry>Mode Name</entry>
- <entry>Abbreviation</entry>
- <entry>Beeps</entry>
- <entry>Description</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>Startup</entry>
- <entry>S</entry>
- <entry>battery voltage in decivolts</entry>
- <entry>
- <para>
- Calibrating sensors, detecting orientation.
- </para>
- </entry>
- </row>
- <row>
- <entry>Idle</entry>
- <entry>I</entry>
- <entry>dit dit</entry>
- <entry>
- <para>
- Ready to accept commands over USB or radio link.
- </para>
- </entry>
- </row>
- <row>
- <entry>Pad</entry>
- <entry>P</entry>
- <entry>dit dah dah dit</entry>
- <entry>
- <para>
- Waiting for launch. Not listening for commands.
- </para>
- </entry>
- </row>
- <row>
- <entry>Boost</entry>
- <entry>B</entry>
- <entry>dah dit dit dit</entry>
- <entry>
- <para>
- Accelerating upwards.
- </para>
- </entry>
- </row>
- <row>
- <entry>Fast</entry>
- <entry>F</entry>
- <entry>dit dit dah dit</entry>
- <entry>
- <para>
- Decelerating, but moving faster than 200m/s.
- </para>
- </entry>
- </row>
- <row>
- <entry>Coast</entry>
- <entry>C</entry>
- <entry>dah dit dah dit</entry>
- <entry>
- <para>
- Decelerating, moving slower than 200m/s
- </para>
- </entry>
- </row>
- <row>
- <entry>Drogue</entry>
- <entry>D</entry>
- <entry>dah dit dit</entry>
- <entry>
- <para>
- Descending after apogee. Above main height.
- </para>
- </entry>
- </row>
- <row>
- <entry>Main</entry>
- <entry>M</entry>
- <entry>dah dah</entry>
- <entry>
- <para>
- Descending. Below main height.
- </para>
- </entry>
- </row>
- <row>
- <entry>Landed</entry>
- <entry>L</entry>
- <entry>dit dah dit dit</entry>
- <entry>
- <para>
- Stable altitude for at least ten seconds.
- </para>
- </entry>
- </row>
- <row>
- <entry>Sensor error</entry>
- <entry>X</entry>
- <entry>dah dit dit dah</entry>
- <entry>
- <para>
- Error detected during sensor calibration.
- </para>
- </entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </para>
- <para>
- In flight or “pad” mode, the altimeter engages the flight
- state machine, goes into transmit-only mode to send telemetry,
- and waits for launch to be detected. Flight mode is indicated
- by an “di-dah-dah-dit” (“P” for pad) on the beeper or lights,
- followed by beeps or flashes indicating the state of the
- pyrotechnic igniter continuity. One beep/flash indicates
- apogee continuity, two beeps/flashes indicate main continuity,
- three beeps/flashes indicate both apogee and main continuity,
- and one longer “brap” sound which is made by rapidly
- alternating between two tones indicates no continuity. For a
- dual deploy flight, make sure you're getting three beeps or
- flashes before launching! For apogee-only or motor eject
- flights, do what makes sense.
- </para>
- <para>
- If idle mode is entered, you will hear an audible “di-dit” or
- see two short flashes (“I” for idle), and the flight state
- machine is disengaged, thus no ejection charges will fire.
- The altimeters also listen for the radio link when in idle
- mode for requests sent via TeleDongle. Commands can be issued
- in idle mode over either USB or the radio link
- equivalently. TeleMini v1.0 only has the radio link. Idle
- mode is useful for configuring the altimeter, for extracting
- data from the on-board storage chip after flight, and for
- ground testing pyro charges.
- </para>
- <para>
- In “Idle” and “Pad” modes, once the mode indication
- beeps/flashes and continuity indication has been sent, if
- there is no space available to log the flight in on-board
- memory, the flight computer will emit a warbling tone (much
- slower than the “no continuity tone”)
- </para>
- <para>
- Here's a summary of all of the “pad” and “idle” mode indications.
- <table frame='all'>
- <title>Pad/Idle Indications</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='3' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Name'/>
- <colspec align='center' colwidth='*' colname='Beeps'/>
- <colspec align='center' colwidth='*' colname='Description'/>
- <thead>
- <row>
- <entry>Name</entry>
- <entry>Beeps</entry>
- <entry>Description</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>Neither</entry>
- <entry>brap</entry>
- <entry>
- <para>
- No continuity detected on either apogee or main
- igniters.
- </para>
- </entry>
- </row>
- <row>
- <entry>Apogee</entry>
- <entry>dit</entry>
- <entry>
- <para>
- Continuity detected only on apogee igniter.
- </para>
- </entry>
- </row>
- <row>
- <entry>Main</entry>
- <entry>dit dit</entry>
- <entry>
- <para>
- Continuity detected only on main igniter.
- </para>
- </entry>
- </row>
- <row>
- <entry>Both</entry>
- <entry>dit dit dit</entry>
- <entry>
- <para>
- Continuity detected on both igniters.
- </para>
- </entry>
- </row>
- <row>
- <entry>Storage Full</entry>
- <entry>warble</entry>
- <entry>
- <para>
- On-board data logging storage is full. This will
- not prevent the flight computer from safely
- controlling the flight or transmitting telemetry
- signals, but no record of the flight will be
- stored in on-board flash.
- </para>
- </entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </para>
- <para>
- Once landed, the flight computer will signal that by emitting
- the “Landed” sound described above, after which it will beep
- out the apogee height (in meters). Each digit is represented
- by a sequence of short “dit” beeps, with a pause between
- digits. A zero digit is represented with one long “dah”
- beep. The flight computer will continue to report landed mode
- and beep out the maximum height until turned off.
- </para>
- <para>
- One “neat trick” of particular value when TeleMetrum, TeleMega
- or EasyMega are used with
- very large air-frames, is that you can power the board up while the
- rocket is horizontal, such that it comes up in idle mode. Then you can
- raise the air-frame to launch position, and issue a 'reset' command
- via TeleDongle over the radio link to cause the altimeter to reboot and
- come up in flight mode. This is much safer than standing on the top
- step of a rickety step-ladder or hanging off the side of a launch
- tower with a screw-driver trying to turn on your avionics before
- installing igniters!
- </para>
- <para>
- TeleMini v1.0 is configured solely via the radio link. Of course, that
- means you need to know the TeleMini radio configuration values
- or you won't be able to communicate with it. For situations
- when you don't have the radio configuration values, TeleMini v1.0
- offers an 'emergency recovery' mode. In this mode, TeleMini is
- configured as follows:
- <itemizedlist>
- <listitem>
- <para>
- Sets the radio frequency to 434.550MHz
- </para>
- </listitem>
- <listitem>
- <para>
- Sets the radio calibration back to the factory value.
- </para>
- </listitem>
- <listitem>
- <para>
- Sets the callsign to N0CALL
- </para>
- </listitem>
- <listitem>
- <para>
- Does not go to 'pad' mode after five seconds.
- </para>
- </listitem>
- </itemizedlist>
- </para>
- <para>
- To get into 'emergency recovery' mode, first find the row of
- four small holes opposite the switch wiring. Using a short
- piece of small gauge wire, connect the outer two holes
- together, then power TeleMini up. Once the red LED is lit,
- disconnect the wire and the board should signal that it's in
- 'idle' mode after the initial five second startup period.
- </para>
- </section>
- <section>
- <title>GPS </title>
- <para>
- TeleMetrum and TeleMega include a complete GPS receiver. A
- complete explanation of how GPS works is beyond the scope of
- this manual, but the bottom line is that the GPS receiver
- needs to lock onto at least four satellites to obtain a solid
- 3 dimensional position fix and know what time it is.
- </para>
- <para>
- The flight computers provide backup power to the GPS chip any time a
- battery is connected. This allows the receiver to “warm start” on
- the launch rail much faster than if every power-on were a GPS
- “cold start”. In typical operations, powering up
- on the flight line in idle mode while performing final air-frame
- preparation will be sufficient to allow the GPS receiver to cold
- start and acquire lock. Then the board can be powered down during
- RSO review and installation on a launch rod or rail. When the board
- is turned back on, the GPS system should lock very quickly, typically
- long before igniter installation and return to the flight line are
- complete.
- </para>
- </section>
- <section>
- <title>Controlling An Altimeter Over The Radio Link</title>
- <para>
- One of the unique features of the Altus Metrum system is the
- ability to create a two way command link between TeleDongle
- and an altimeter using the digital radio transceivers
- built into each device. This allows you to interact with the
- altimeter from afar, as if it were directly connected to the
- computer.
- </para>
- <para>
- Any operation which can be performed with a flight computer can
- either be done with the device directly connected to the
- computer via the USB cable, or through the radio
- link. TeleMini v1.0 doesn't provide a USB connector and so it is
- always communicated with over radio. Select the appropriate
- TeleDongle device when the list of devices is presented and
- AltosUI will interact with an altimeter over the radio link.
- </para>
- <para>
- One oddity in the current interface is how AltosUI selects the
- frequency for radio communications. Instead of providing
- an interface to specifically configure the frequency, it uses
- whatever frequency was most recently selected for the target
- TeleDongle device in Monitor Flight mode. If you haven't ever
- used that mode with the TeleDongle in question, select the
- Monitor Flight button from the top level UI, and pick the
- appropriate TeleDongle device. Once the flight monitoring
- window is open, select the desired frequency and then close it
- down again. All radio communications will now use that frequency.
- </para>
- <itemizedlist>
- <listitem>
- <para>
- Save Flight Data—Recover flight data from the rocket without
- opening it up.
- </para>
- </listitem>
- <listitem>
- <para>
- Configure altimeter apogee delays, main deploy heights
- and additional pyro event conditions
- to respond to changing launch conditions. You can also
- 'reboot' the altimeter. Use this to remotely enable the
- flight computer by turning TeleMetrum or TeleMega on in “idle” mode,
- then once the air-frame is oriented for launch, you can
- reboot the altimeter and have it restart in pad mode
- without having to climb the scary ladder.
- </para>
- </listitem>
- <listitem>
- <para>
- Fire Igniters—Test your deployment charges without snaking
- wires out through holes in the air-frame. Simply assemble the
- rocket as if for flight with the apogee and main charges
- loaded, then remotely command the altimeter to fire the
- igniters.
- </para>
- </listitem>
- </itemizedlist>
- <para>
- Operation over the radio link for configuring an altimeter, ground
- testing igniters, and so forth uses the same RF frequencies as flight
- telemetry. To configure the desired TeleDongle frequency, select
- the monitor flight tab, then use the frequency selector and
- close the window before performing other desired radio operations.
- </para>
- <para>
- The flight computers only enable radio commanding in 'idle' mode.
- TeleMetrum and TeleMega use the accelerometer to detect which orientation they
- start up in, so make sure you have the flight computer lying horizontally when you turn
- it on. Otherwise, it will start in 'pad' mode ready for
- flight, and will not be listening for command packets from TeleDongle.
- </para>
- <para>
- TeleMini listens for a command packet for five seconds after
- first being turned on, if it doesn't hear anything, it enters
- 'pad' mode, ready for flight and will no longer listen for
- command packets. The easiest way to connect to TeleMini is to
- initiate the command and select the TeleDongle device. At this
- point, the TeleDongle will be attempting to communicate with
- the TeleMini. Now turn TeleMini on, and it should immediately
- start communicating with the TeleDongle and the desired
- operation can be performed.
- </para>
- <para>
- You can monitor the operation of the radio link by watching the
- lights on the devices. The red LED will flash each time a packet
- is transmitted, while the green LED will light up on TeleDongle when
- it is waiting to receive a packet from the altimeter.
- </para>
- </section>
- <section>
- <title>Ground Testing </title>
- <para>
- An important aspect of preparing a rocket using electronic deployment
- for flight is ground testing the recovery system. Thanks
- to the bi-directional radio link central to the Altus Metrum system,
- this can be accomplished in a TeleMega, TeleMetrum or TeleMini equipped rocket
- with less work than you may be accustomed to with other systems. It
- can even be fun!
- </para>
- <para>
- Just prep the rocket for flight, then power up the altimeter
- in “idle” mode (placing air-frame horizontal for TeleMetrum or TeleMega, or
- selecting the Configure Altimeter tab for TeleMini). This will cause
- the firmware to go into “idle” mode, in which the normal flight
- state machine is disabled and charges will not fire without
- manual command. You can now command the altimeter to fire the apogee
- or main charges from a safe distance using your computer and
- TeleDongle and the Fire Igniter tab to complete ejection testing.
- </para>
- </section>
- <section>
- <title>Radio Link </title>
- <para>
- Our flight computers all incorporate an RF transceiver, but
- it's not a full duplex system... each end can only be transmitting or
- receiving at any given moment. So we had to decide how to manage the
- link.
- </para>
- <para>
- By design, the altimeter firmware listens for the radio link when
- it's in “idle mode”, which
- allows us to use the radio link to configure the rocket, do things like
- ejection tests, and extract data after a flight without having to
- crack open the air-frame. However, when the board is in “flight
- mode”, the altimeter only
- transmits and doesn't listen at all. That's because we want to put
- ultimate priority on event detection and getting telemetry out of
- the rocket through
- the radio in case the rocket crashes and we aren't able to extract
- data later...
- </para>
- <para>
- We don't generally use a 'normal packet radio' mode like APRS
- because they're just too inefficient. The GFSK modulation we
- use is FSK with the base-band pulses passed through a Gaussian
- filter before they go into the modulator to limit the
- transmitted bandwidth. When combined with forward error
- correction and interleaving, this allows us to have a very
- robust 19.2 kilobit data link with only 10-40 milliwatts of
- transmit power, a whip antenna in the rocket, and a hand-held
- Yagi on the ground. We've had flights to above 21k feet AGL
- with great reception, and calculations suggest we should be
- good to well over 40k feet AGL with a 5-element yagi on the
- ground with our 10mW units and over 100k feet AGL with the
- 40mW devices. We hope to fly boards to higher altitudes over
- time, and would of course appreciate customer feedback on
- performance in higher altitude flights!
- </para>
- </section>
- <section>
- <title>APRS</title>
- <para>
- TeleMetrum v2.0 and TeleMega can send APRS if desired, and the
- interval between APRS packets can be configured. As each APRS
- packet takes a full second to transmit, we recommend an
- interval of at least 5 seconds to avoid consuming too much
- battery power or radio channel bandwidth. You can configure
- the APRS interval using AltosUI; that process is described in
- the Configure Altimeter section of the AltosUI chapter.
- </para>
- <para>
- AltOS uses the APRS compressed position report data format,
- which provides for higher position precision and shorter
- packets than the original APRS format. It also includes
- altitude data, which is invaluable when tracking rockets. We
- haven't found a receiver which doesn't handle compressed
- positions, but it's just possible that you have one, so if you
- have an older device that can receive the raw packets but
- isn't displaying position information, it's possible that this
- is the cause.
- </para>
- <para>
- APRS packets include an SSID (Secondary Station Identifier)
- field that allows one operator to have multiple
- transmitters. AltOS allows you to set this to a single digit
- from 0 to 9, allowing you to fly multiple transmitters at the
- same time while keeping the identify of each one separate in
- the receiver. By default, the SSID is set to the last digit of
- the device serial number.
- </para>
- <para>
- The APRS packet format includes a comment field that can have
- arbitrary text in it. AltOS uses this to send status
- information about the flight computer. It sends four fields as
- shown in the following table.
- </para>
- <table frame='all'>
- <title>Altus Metrum APRS Comments</title>
- <?dbfo keep-together="always"?>
- <tgroup cols='3' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Field'/>
- <colspec align='center' colwidth='*' colname='Example'/>
- <colspec align='center' colwidth='4*' colname='Description'/>
- <thead>
- <row>
- <entry align='center'>Field</entry>
- <entry align='center'>Example</entry>
- <entry align='center'>Description</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>1</entry>
- <entry>L</entry>
- <entry>GPS Status U for unlocked, L for locked</entry>
- </row>
- <row>
- <entry>2</entry>
- <entry>6</entry>
- <entry>Number of Satellites in View</entry>
- </row>
- <row>
- <entry>3</entry>
- <entry>B4.0</entry>
- <entry>Altimeter Battery Voltage</entry>
- </row>
- <row>
- <entry>4</entry>
- <entry>A3.7</entry>
- <entry>Apogee Igniter Voltage</entry>
- </row>
- <row>
- <entry>5</entry>
- <entry>M3.7</entry>
- <entry>Main Igniter Voltage</entry>
- </row>
- <row>
- <entry>6</entry>
- <entry>1286</entry>
- <entry>Device Serial Number</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- <para>
- Here's an example of an APRS comment showing GPS lock with 6
- satellites in view, a primary battery at 4.0V, and
- apogee and main igniters both at 3.7V from device 1286.
- <screen>
- L6 B4.0 A3.7 M3.7 1286
- </screen>
- </para>
- <para>
- Make sure your primary battery is above 3.8V, any connected
- igniters are above 3.5V and GPS is locked with at least 5 or 6
- satellites in view before flying. If GPS is switching between
- L and U regularly, then it doesn't have a good lock and you
- should wait until it becomes stable.
- </para>
- <para>
- If the GPS receiver loses lock, the APRS data transmitted will
- contain the last position for which GPS lock was
- available. You can tell that this has happened by noticing
- that the GPS status character switches from 'L' to 'U'. Before
- GPS has locked, APRS will transmit zero for latitude,
- longitude and altitude.
- </para>
- </section>
- <section>
- <title>Configurable Parameters</title>
- <para>
- Configuring an Altus Metrum altimeter for flight is very
- simple. Even on our baro-only TeleMini and EasyMini boards,
- the use of a Kalman filter means there is no need to set a
- “mach delay”. The few configurable parameters can all be set
- using AltosUI over USB or or radio link via TeleDongle. Read
- the Configure Altimeter section in the AltosUI chapter below
- for more information.
- </para>
- <section>
- <title>Radio Frequency</title>
- <para>
- Altus Metrum boards support radio frequencies in the 70cm
- band. By default, the configuration interface provides a
- list of 10 “standard” frequencies in 100kHz channels starting at
- 434.550MHz. However, the firmware supports use of
- any 50kHz multiple within the 70cm band. At any given
- launch, we highly recommend coordinating when and by whom each
- frequency will be used to avoid interference. And of course, both
- altimeter and TeleDongle must be configured to the same
- frequency to successfully communicate with each other.
- </para>
- </section>
- <section>
- <title>Callsign</title>
- <para>
- This sets the callsign used for telemetry, APRS and the
- packet link. For telemetry and APRS, this is used to
- identify the device. For the packet link, the callsign must
- match that configured in AltosUI or the link will not
- work. This is to prevent accidental configuration of another
- Altus Metrum flight computer operating on the same frequency nearby.
- </para>
- </section>
- <section>
- <title>Telemetry/RDF/APRS Enable</title>
- <para>
- You can completely disable the radio while in flight, if
- necessary. This doesn't disable the packet link in idle
- mode.
- </para>
- </section>
- <section>
- <title>Telemetry baud rate</title>
- <para>
- This sets the modulation bit rate for data transmission for
- both telemetry and packet link mode. Lower bit
- rates will increase range while reducing the amount of data
- that can be sent and increasing battery consumption. All
- telemetry is done using a rate 1/2 constraint 4 convolution
- code, so the actual data transmission rate is 1/2 of the
- modulation bit rate specified here.
- </para>
- </section>
- <section>
- <title>APRS Interval</title>
- <para>
- This selects how often APRS packets are transmitted. Set
- this to zero to disable APRS without also disabling the
- regular telemetry and RDF transmissions. As APRS takes a
- full second to transmit a single position report, we
- recommend sending packets no more than once every 5 seconds.
- </para>
- </section>
- <section>
- <title>APRS SSID</title>
- <para>
- This selects the SSID reported in APRS packets. By default,
- it is set to the last digit of the serial number, but you
- can change this to any value from 0 to 9.
- </para>
- </section>
- <section>
- <title>Apogee Delay</title>
- <para>
- Apogee delay is the number of seconds after the altimeter detects flight
- apogee that the drogue charge should be fired. In most cases, this
- should be left at the default of 0. However, if you are flying
- redundant electronics such as for an L3 certification, you may wish
- to set one of your altimeters to a positive delay so that both
- primary and backup pyrotechnic charges do not fire simultaneously.
- </para>
- <para>
- The Altus Metrum apogee detection algorithm fires exactly at
- apogee. If you are also flying an altimeter like the
- PerfectFlite MAWD, which only supports selecting 0 or 1
- seconds of apogee delay, you may wish to set the MAWD to 0
- seconds delay and set the TeleMetrum to fire your backup 2
- or 3 seconds later to avoid any chance of both charges
- firing simultaneously. We've flown several air-frames this
- way quite happily, including Keith's successful L3 cert.
- </para>
- </section>
- <section>
- <title>Apogee Lockout</title>
- <para>
- Apogee lockout is the number of seconds after boost where
- the flight computer will not fire the apogee charge, even if
- the rocket appears to be at apogee. This is often called
- 'Mach Delay', as it is intended to prevent a flight computer
- from unintentionally firing apogee charges due to the pressure
- spike that occurrs across a mach transition. Altus Metrum
- flight computers include a Kalman filter which is not fooled
- by this sharp pressure increase, and so this setting should
- be left at the default value of zero to disable it.
- </para>
- </section>
- <section>
- <title>Main Deployment Altitude</title>
- <para>
- By default, the altimeter will fire the main deployment charge at an
- elevation of 250 meters (about 820 feet) above ground. We think this
- is a good elevation for most air-frames, but feel free to change this
- to suit. In particular, if you are flying two altimeters, you may
- wish to set the
- deployment elevation for the backup altimeter to be something lower
- than the primary so that both pyrotechnic charges don't fire
- simultaneously.
- </para>
- </section>
- <section>
- <title>Maximum Flight Log</title>
- <para>
- Changing this value will set the maximum amount of flight
- log storage that an individual flight will use. The
- available storage is divided into as many flights of the
- specified size as can fit in the available space. You can
- download and erase individual flight logs. If you fill up
- the available storage, future flights will not get logged
- until you erase some of the stored ones.
- </para>
- <para>
- Even though our flight computers (except TeleMini v1.0) can store
- multiple flights, we strongly recommend downloading and saving
- flight data after each flight.
- </para>
- </section>
- <section>
- <title>Ignite Mode</title>
- <para>
- Instead of firing one charge at apogee and another charge at
- a fixed height above the ground, you can configure the
- altimeter to fire both at apogee or both during
- descent. This was added to support an airframe Bdale designed that
- had two altimeters, one in the fin can and one in the nose.
- </para>
- <para>
- Providing the ability to use both igniters for apogee or
- main allows some level of redundancy without needing two
- flight computers. In Redundant Apogee or Redundant Main
- mode, the two charges will be fired two seconds apart.
- </para>
- </section>
- <section>
- <title>Pad Orientation</title>
- <para>
- TeleMetrum, TeleMega and EasyMega measure acceleration along the axis
- of the board. Which way the board is oriented affects the
- sign of the acceleration value. Instead of trying to guess
- which way the board is mounted in the air frame, the
- altimeter must be explicitly configured for either Antenna
- Up or Antenna Down. The default, Antenna Up, expects the end
- of the board connected to the 70cm antenna to be nearest the
- nose of the rocket, with the end containing the screw
- terminals nearest the tail.
- </para>
- </section>
- <section>
- <title>Configurable Pyro Channels</title>
- <para>
- In addition to the usual Apogee and Main pyro channels,
- TeleMega and EasyMega have four additional channels that can be configured
- to activate when various flight conditions are
- satisfied. You can select as many conditions as necessary;
- all of them must be met in order to activate the
- channel. The conditions available are:
- </para>
- <itemizedlist>
- <listitem>
- <para>
- Acceleration away from the ground. Select a value, and
- then choose whether acceleration should be above or
- below that value. Acceleration is positive upwards, so
- accelerating towards the ground would produce negative
- numbers. Acceleration during descent is noisy and
- inaccurate, so be careful when using it during these
- phases of the flight.
- </para>
- </listitem>
- <listitem>
- <para>
- Vertical speed. Select a value, and then choose whether
- vertical speed should be above or below that
- value. Speed is positive upwards, so moving towards the
- ground would produce negative numbers. Speed during
- descent is a bit noisy and so be careful when using it
- during these phases of the flight.
- </para>
- </listitem>
- <listitem>
- <para>
- Height. Select a value, and then choose whether the
- height above the launch pad should be above or below
- that value.
- </para>
- </listitem>
- <listitem>
- <para>
- Orientation. TeleMega and EasyMega contain a 3-axis gyroscope and
- accelerometer which is used to measure the current
- angle. Note that this angle is not the change in angle
- from the launch pad, but rather absolute relative to
- gravity; the 3-axis accelerometer is used to compute the
- angle of the rocket on the launch pad and initialize the
- system. Because this value is computed by integrating
- rate gyros, it gets progressively less accurate as the
- flight goes on. It should have an accumulated error of
- less than 0.2°/second (after 10 seconds of flight, the
- error should be less than 2°).
- </para>
- <para>
- The usual use of the orientation configuration is to
- ensure that the rocket is traveling mostly upwards when
- deciding whether to ignite air starts or additional
- stages. For that, choose a reasonable maximum angle
- (like 20°) and set the motor igniter to require an angle
- of less than that value.
- </para>
- </listitem>
- <listitem>
- <para>
- Flight Time. Time since boost was detected. Select a
- value and choose whether to activate the pyro channel
- before or after that amount of time.
- </para>
- </listitem>
- <listitem>
- <para>
- Ascending. A simple test saying whether the rocket is
- going up or not. This is exactly equivalent to testing
- whether the speed is > 0.
- </para>
- </listitem>
- <listitem>
- <para>
- Descending. A simple test saying whether the rocket is
- going down or not. This is exactly equivalent to testing
- whether the speed is < 0.
- </para>
- </listitem>
- <listitem>
- <para>
- After Motor. The flight software counts each time the
- rocket starts accelerating and then decelerating
- (presumably due to a motor or motors burning). Use this
- value for multi-staged or multi-airstart launches.
- </para>
- </listitem>
- <listitem>
- <para>
- Delay. This value doesn't perform any checks, instead it
- inserts a delay between the time when the other
- parameters become true and when the pyro channel is
- activated.
- </para>
- </listitem>
- <listitem>
- <para>
- Flight State. The flight software tracks the flight
- through a sequence of states:
- <orderedlist>
- <listitem>
- <para>
- Boost. The motor has lit and the rocket is
- accelerating upwards.
- </para>
- </listitem>
- <listitem>
- <para>
- Fast. The motor has burned out and the rocket is
- decelerating, but it is going faster than 200m/s.
- </para>
- </listitem>
- <listitem>
- <para>
- Coast. The rocket is still moving upwards and
- decelerating, but the speed is less than 200m/s.
- </para>
- </listitem>
- <listitem>
- <para>
- Drogue. The rocket has reached apogee and is heading
- back down, but is above the configured Main
- altitude.
- </para>
- </listitem>
- <listitem>
- <para>
- Main. The rocket is still descending, and is below
- the Main altitude
- </para>
- </listitem>
- <listitem>
- <para>
- Landed. The rocket is no longer moving.
- </para>
- </listitem>
- </orderedlist>
- </para>
- <para>
- You can select a state to limit when the pyro channel
- may activate; note that the check is based on when the
- rocket transitions <emphasis>into</emphasis> the state, and so checking for
- “greater than Boost” means that the rocket is currently
- in boost or some later state.
- </para>
- <para>
- When a motor burns out, the rocket enters either Fast or
- Coast state (depending on how fast it is moving). If the
- computer detects upwards acceleration again, it will
- move back to Boost state.
- </para>
- </listitem>
- </itemizedlist>
- </section>
- </section>
-
- </chapter>
- <chapter>
- <title>AltosUI</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="altosui.png" width="4.6in"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- The AltosUI program provides a graphical user interface for
- interacting with the Altus Metrum product family. AltosUI can
- monitor telemetry data, configure devices and many other
- tasks. The primary interface window provides a selection of
- buttons, one for each major activity in the system. This chapter
- is split into sections, each of which documents one of the tasks
- provided from the top-level toolbar.
- </para>
- <section>
- <title>Monitor Flight</title>
- <subtitle>Receive, Record and Display Telemetry Data</subtitle>
- <para>
- Selecting this item brings up a dialog box listing all of the
- connected TeleDongle devices. When you choose one of these,
- AltosUI will create a window to display telemetry data as
- received by the selected TeleDongle device.
- </para>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="device-selection.png" width="3.1in"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- All telemetry data received are automatically recorded in
- suitable log files. The name of the files includes the current
- date and rocket serial and flight numbers.
- </para>
- <para>
- The radio frequency being monitored by the TeleDongle device is
- displayed at the top of the window. You can configure the
- frequency by clicking on the frequency box and selecting the desired
- frequency. AltosUI remembers the last frequency selected for each
- TeleDongle and selects that automatically the next time you use
- that device.
- </para>
- <para>
- Below the TeleDongle frequency selector, the window contains a few
- significant pieces of information about the altimeter providing
- the telemetry data stream:
- </para>
- <itemizedlist>
- <listitem>
- <para>The configured call-sign</para>
- </listitem>
- <listitem>
- <para>The device serial number</para>
- </listitem>
- <listitem>
- <para>The flight number. Each altimeter remembers how many
- times it has flown.
- </para>
- </listitem>
- <listitem>
- <para>
- The rocket flight state. Each flight passes through several
- states including Pad, Boost, Fast, Coast, Drogue, Main and
- Landed.
- </para>
- </listitem>
- <listitem>
- <para>
- The Received Signal Strength Indicator value. This lets
- you know how strong a signal TeleDongle is receiving. At
- the default data rate, 38400 bps, in bench testing, the
- radio inside TeleDongle v0.2 operates down to about
- -106dBm, while the v3 radio works down to about -111dBm.
- Weaker signals, or an environment with radio noise may
- cause the data to not be received. The packet link uses
- error detection and correction techniques which prevent
- incorrect data from being reported.
- </para>
- </listitem>
- <listitem>
- <para>
- The age of the displayed data, in seconds since the last
- successfully received telemetry packet. In normal operation
- this will stay in the low single digits. If the number starts
- counting up, then you are no longer receiving data over the radio
- link from the flight computer.
- </para>
- </listitem>
- </itemizedlist>
- <para>
- Finally, the largest portion of the window contains a set of
- tabs, each of which contain some information about the rocket.
- They're arranged in 'flight order' so that as the flight
- progresses, the selected tab automatically switches to display
- data relevant to the current state of the flight. You can select
- other tabs at any time. The final 'table' tab displays all of
- the raw telemetry values in one place in a spreadsheet-like format.
- </para>
- <section>
- <title>Launch Pad</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="launch-pad.png" width="5.5in"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- The 'Launch Pad' tab shows information used to decide when the
- rocket is ready for flight. The first elements include red/green
- indicators, if any of these is red, you'll want to evaluate
- whether the rocket is ready to launch:
- <variablelist>
- <varlistentry>
- <term>Battery Voltage</term>
- <listitem>
- <para>
- This indicates whether the Li-Po battery powering the
- flight computer has sufficient charge to last for
- the duration of the flight. A value of more than
- 3.8V is required for a 'GO' status.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Apogee Igniter Voltage</term>
- <listitem>
- <para>
- This indicates whether the apogee
- igniter has continuity. If the igniter has a low
- resistance, then the voltage measured here will be close
- to the Li-Po battery voltage. A value greater than 3.2V is
- required for a 'GO' status.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Main Igniter Voltage</term>
- <listitem>
- <para>
- This indicates whether the main
- igniter has continuity. If the igniter has a low
- resistance, then the voltage measured here will be close
- to the Li-Po battery voltage. A value greater than 3.2V is
- required for a 'GO' status.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>On-board Data Logging</term>
- <listitem>
- <para>
- This indicates whether there is
- space remaining on-board to store flight data for the
- upcoming flight. If you've downloaded data, but failed
- to erase flights, there may not be any space
- left. Most of our flight computers can store multiple
- flights, depending on the configured maximum flight log
- size. TeleMini v1.0 stores only a single flight, so it
- will need to be
- downloaded and erased after each flight to capture
- data. This only affects on-board flight logging; the
- altimeter will still transmit telemetry and fire
- ejection charges at the proper times even if the flight
- data storage is full.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>GPS Locked</term>
- <listitem>
- <para>
- For a TeleMetrum or TeleMega device, this indicates whether the GPS receiver is
- currently able to compute position information. GPS requires
- at least 4 satellites to compute an accurate position.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>GPS Ready</term>
- <listitem>
- <para>
- For a TeleMetrum or TeleMega device, this indicates whether GPS has reported at least
- 10 consecutive positions without losing lock. This ensures
- that the GPS receiver has reliable reception from the
- satellites.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- </para>
- <para>
- The Launchpad tab also shows the computed launch pad position
- and altitude, averaging many reported positions to improve the
- accuracy of the fix.
- </para>
- </section>
- <section>
- <title>Ascent</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="ascent.png" width="5.5in"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- This tab is shown during Boost, Fast and Coast
- phases. The information displayed here helps monitor the
- rocket as it heads towards apogee.
- </para>
- <para>
- The height, speed, acceleration and tilt are shown along
- with the maximum values for each of them. This allows you to
- quickly answer the most commonly asked questions you'll hear
- during flight.
- </para>
- <para>
- The current latitude and longitude reported by the GPS are
- also shown. Note that under high acceleration, these values
- may not get updated as the GPS receiver loses position
- fix. Once the rocket starts coasting, the receiver should
- start reporting position again.
- </para>
- <para>
- Finally, the current igniter voltages are reported as in the
- Launch Pad tab. This can help diagnose deployment failures
- caused by wiring which comes loose under high acceleration.
- </para>
- </section>
- <section>
- <title>Descent</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="descent.png" width="5.5in"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- Once the rocket has reached apogee and (we hope) activated the
- apogee charge, attention switches to tracking the rocket on
- the way back to the ground, and for dual-deploy flights,
- waiting for the main charge to fire.
- </para>
- <para>
- To monitor whether the apogee charge operated correctly, the
- current descent rate is reported along with the current
- height. Good descent rates vary based on the choice of recovery
- components, but generally range from 15-30m/s on drogue and should
- be below 10m/s when under the main parachute in a dual-deploy flight.
- </para>
- <para>
- With GPS-equipped flight computers, you can locate the rocket in the
- sky using the elevation and bearing information to figure
- out where to look. Elevation is in degrees above the
- horizon. Bearing is reported in degrees relative to true
- north. Range can help figure out how big the rocket will
- appear. Ground Distance shows how far it is to a point
- directly under the rocket and can help figure out where the
- rocket is likely to land. Note that all of these values are
- relative to the pad location. If the elevation is near 90°,
- the rocket is over the pad, not over you.
- </para>
- <para>
- Finally, the igniter voltages are reported in this tab as
- well, both to monitor the main charge as well as to see what
- the status of the apogee charge is. Note that some commercial
- e-matches are designed to retain continuity even after being
- fired, and will continue to show as green or return from red to
- green after firing.
- </para>
- </section>
- <section>
- <title>Landed</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="landed.png" width="5.5in"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- Once the rocket is on the ground, attention switches to
- recovery. While the radio signal is often lost once the
- rocket is on the ground, the last reported GPS position is
- generally within a short distance of the actual landing location.
- </para>
- <para>
- The last reported GPS position is reported both by
- latitude and longitude as well as a bearing and distance from
- the launch pad. The distance should give you a good idea of
- whether to walk or hitch a ride. Take the reported
- latitude and longitude and enter them into your hand-held GPS
- unit and have that compute a track to the landing location.
- </para>
- <para>
- Our flight computers will continue to transmit RDF
- tones after landing, allowing you to locate the rocket by
- following the radio signal if necessary. You may need to get
- away from the clutter of the flight line, or even get up on
- a hill (or your neighbor's RV roof) to receive the RDF signal.
- </para>
- <para>
- The maximum height, speed and acceleration reported
- during the flight are displayed for your admiring observers.
- The accuracy of these immediate values depends on the quality
- of your radio link and how many packets were received.
- Recovering the on-board data after flight may yield
- more precise results.
- </para>
- <para>
- To get more detailed information about the flight, you can
- click on the 'Graph Flight' button which will bring up a
- graph window for the current flight.
- </para>
- </section>
- <section>
- <title>Table</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="table.png" width="5.5in"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- The table view shows all of the data available from the
- flight computer. Probably the most useful data on
- this tab is the detailed GPS information, which includes
- horizontal dilution of precision information, and
- information about the signal being received from the satellites.
- </para>
- </section>
- <section>
- <title>Site Map</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="site-map.png" width="5.5in"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- When the TeleMetrum has a GPS fix, the Site Map tab will map
- the rocket's position to make it easier for you to locate the
- rocket, both while it is in the air, and when it has landed. The
- rocket's state is indicated by color: white for pad, red for
- boost, pink for fast, yellow for coast, light blue for drogue,
- dark blue for main, and black for landed.
- </para>
- <para>
- The map's default scale is approximately 3m (10ft) per pixel. The map
- can be dragged using the left mouse button. The map will attempt
- to keep the rocket roughly centered while data is being received.
- </para>
- <para>
- You can adjust the style of map and the zoom level with
- buttons on the right side of the map window. You can draw a
- line on the map by moving the mouse over the map with a
- button other than the left one pressed, or by pressing the
- left button while also holding down the shift key. The
- length of the line in real-world units will be shown at the
- start of the line.
- </para>
- <para>
- Images are fetched automatically via the Google Maps Static API,
- and cached on disk for reuse. If map images cannot be downloaded,
- the rocket's path will be traced on a dark gray background
- instead.
- </para>
- <para>
- You can pre-load images for your favorite launch sites
- before you leave home; check out the 'Preload Maps' section below.
- </para>
- </section>
- <section>
- <title>Ignitor</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="ignitor.png" width="5.5in"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- TeleMega includes four additional programmable pyro
- channels. The Ignitor tab shows whether each of them has
- continuity. If an ignitor has a low resistance, then the
- voltage measured here will be close to the pyro battery
- voltage. A value greater than 3.2V is required for a 'GO'
- status.
- </para>
- </section>
- </section>
- <section>
- <title>Save Flight Data</title>
- <para>
- The altimeter records flight data to its internal flash memory.
- TeleMetrum data is recorded at a much higher rate than the telemetry
- system can handle, and is not subject to radio drop-outs. As
- such, it provides a more complete and precise record of the
- flight. The 'Save Flight Data' button allows you to read the
- flash memory and write it to disk.
- </para>
- <para>
- Clicking on the 'Save Flight Data' button brings up a list of
- connected flight computers and TeleDongle devices. If you select a
- flight computer, the flight data will be downloaded from that
- device directly. If you select a TeleDongle device, flight data
- will be downloaded from a flight computer over radio link via the
- specified TeleDongle. See the chapter on Controlling An Altimeter
- Over The Radio Link for more information.
- </para>
- <para>
- After the device has been selected, a dialog showing the
- flight data saved in the device will be shown allowing you to
- select which flights to download and which to delete. With
- version 0.9 or newer firmware, you must erase flights in order
- for the space they consume to be reused by another
- flight. This prevents accidentally losing flight data
- if you neglect to download data before flying again. Note that
- if there is no more space available in the device, then no
- data will be recorded during the next flight.
- </para>
- <para>
- The file name for each flight log is computed automatically
- from the recorded flight date, altimeter serial number and
- flight number information.
- </para>
- </section>
- <section>
- <title>Replay Flight</title>
- <para>
- Select this button and you are prompted to select a flight
- record file, either a .telem file recording telemetry data or a
- .eeprom file containing flight data saved from the altimeter
- flash memory.
- </para>
- <para>
- Once a flight record is selected, the flight monitor interface
- is displayed and the flight is re-enacted in real time. Check
- the Monitor Flight chapter above to learn how this window operates.
- </para>
- </section>
- <section>
- <title>Graph Data</title>
- <para>
- Select this button and you are prompted to select a flight
- record file, either a .telem file recording telemetry data or a
- .eeprom file containing flight data saved from
- flash memory.
- </para>
- <para>
- Note that telemetry files will generally produce poor graphs
- due to the lower sampling rate and missed telemetry packets.
- Use saved flight data in .eeprom files for graphing where possible.
- </para>
- <para>
- Once a flight record is selected, a window with multiple tabs is
- opened.
- </para>
- <section>
- <title>Flight Graph</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="graph.png" width="6in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- By default, the graph contains acceleration (blue),
- velocity (green) and altitude (red).
- </para>
- <para>
- The graph can be zoomed into a particular area by clicking and
- dragging down and to the right. Once zoomed, the graph can be
- reset by clicking and dragging up and to the left. Holding down
- control and clicking and dragging allows the graph to be panned.
- The right mouse button causes a pop-up menu to be displayed, giving
- you the option save or print the plot.
- </para>
- </section>
- <section>
- <title>Configure Graph</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="graph-configure.png" width="6in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- This selects which graph elements to show, and, at the
- very bottom, lets you switch between metric and
- imperial units
- </para>
- </section>
- <section>
- <title>Flight Statistics</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="graph-stats.png" width="6in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- Shows overall data computed from the flight.
- </para>
- </section>
- <section>
- <title>Map</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="graph-map.png" width="6in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- Shows a satellite image of the flight area overlaid
- with the path of the flight. The red concentric
- circles mark the launch pad, the black concentric
- circles mark the landing location.
- </para>
- </section>
- </section>
- <section>
- <title>Export Data</title>
- <para>
- This tool takes the raw data files and makes them available for
- external analysis. When you select this button, you are prompted to
- select a flight data file, which can be either a .eeprom or .telem.
- The .eeprom files contain higher resolution and more continuous data,
- while .telem files contain receiver signal strength information.
- Next, a second dialog appears which is used to select
- where to write the resulting file. It has a selector to choose
- between CSV and KML file formats.
- </para>
- <section>
- <title>Comma Separated Value Format</title>
- <para>
- This is a text file containing the data in a form suitable for
- import into a spreadsheet or other external data analysis
- tool. The first few lines of the file contain the version and
- configuration information from the altimeter, then
- there is a single header line which labels all of the
- fields. All of these lines start with a '#' character which
- many tools can be configured to skip over.
- </para>
- <para>
- The remaining lines of the file contain the data, with each
- field separated by a comma and at least one space. All of
- the sensor values are converted to standard units, with the
- barometric data reported in both pressure, altitude and
- height above pad units.
- </para>
- </section>
- <section>
- <title>Keyhole Markup Language (for Google Earth)</title>
- <para>
- This is the format used by Google Earth to provide an overlay
- within that application. With this, you can use Google Earth to
- see the whole flight path in 3D.
- </para>
- </section>
- </section>
- <section>
- <title>Configure Altimeter</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="configure-altimeter.png" width="3.6in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- Select this button and then select either an altimeter or
- TeleDongle Device from the list provided. Selecting a TeleDongle
- device will use the radio link to configure a remote altimeter.
- </para>
- <para>
- The first few lines of the dialog provide information about the
- connected device, including the product name,
- software version and hardware serial number. Below that are the
- individual configuration entries.
- </para>
- <para>
- At the bottom of the dialog, there are four buttons:
- </para>
- <variablelist>
- <varlistentry>
- <term>Save</term>
- <listitem>
- <para>
- This writes any changes to the
- configuration parameter block in flash memory. If you don't
- press this button, any changes you make will be lost.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Reset</term>
- <listitem>
- <para>
- This resets the dialog to the most recently saved values,
- erasing any changes you have made.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Reboot</term>
- <listitem>
- <para>
- This reboots the device. Use this to
- switch from idle to pad mode by rebooting once the rocket is
- oriented for flight, or to confirm changes you think you saved
- are really saved.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Close</term>
- <listitem>
- <para>
- This closes the dialog. Any unsaved changes will be
- lost.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- <para>
- The rest of the dialog contains the parameters to be configured.
- </para>
- <section>
- <title>Main Deploy Altitude</title>
- <para>
- This sets the altitude (above the recorded pad altitude) at
- which the 'main' igniter will fire. The drop-down menu shows
- some common values, but you can edit the text directly and
- choose whatever you like. If the apogee charge fires below
- this altitude, then the main charge will fire two seconds
- after the apogee charge fires.
- </para>
- </section>
- <section>
- <title>Apogee Delay</title>
- <para>
- When flying redundant electronics, it's often important to
- ensure that multiple apogee charges don't fire at precisely
- the same time, as that can over pressurize the apogee deployment
- bay and cause a structural failure of the air-frame. The Apogee
- Delay parameter tells the flight computer to fire the apogee
- charge a certain number of seconds after apogee has been
- detected.
- </para>
- </section>
- <section>
- <title>Apogee Lockoug</title>
- <para>
- Apogee lockout is the number of seconds after boost where
- the flight computer will not fire the apogee charge, even if
- the rocket appears to be at apogee. This is often called
- 'Mach Delay', as it is intended to prevent a flight computer
- from unintentionally firing apogee charges due to the pressure
- spike that occurrs across a mach transition. Altus Metrum
- flight computers include a Kalman filter which is not fooled
- by this sharp pressure increase, and so this setting should
- be left at the default value of zero to disable it.
- </para>
- </section>
- <section>
- <title>Frequency</title>
- <para>
- This configures which of the frequencies to use for both
- telemetry and packet command mode. Note that if you set this
- value via packet command mode, the TeleDongle frequency will
- also be automatically reconfigured to match so that
- communication will continue afterwards.
- </para>
- </section>
- <section>
- <title>RF Calibration</title>
- <para>
- The radios in every Altus Metrum device are calibrated at the
- factory to ensure that they transmit and receive on the
- specified frequency. If you need to you can adjust the calibration
- by changing this value. Do not do this without understanding what
- the value means, read the appendix on calibration and/or the source
- code for more information. To change a TeleDongle's calibration,
- you must reprogram the unit completely.
- </para>
- </section>
- <section>
- <title>Telemetry/RDF/APRS Enable</title>
- <para>
- Enables the radio for transmission during flight. When
- disabled, the radio will not transmit anything during flight
- at all.
- </para>
- </section>
- <section>
- <title>Telemetry baud rate</title>
- <para>
- This sets the modulation bit rate for data transmission for
- both telemetry and packet link mode. Lower bit
- rates will increase range while reducing the amount of data
- that can be sent and increasing battery consumption. All
- telemetry is done using a rate 1/2 constraint 4 convolution
- code, so the actual data transmission rate is 1/2 of the
- modulation bit rate specified here.
- </para>
- </section>
- <section>
- <title>APRS Interval</title>
- <para>
- How often to transmit GPS information via APRS (in
- seconds). When set to zero, APRS transmission is
- disabled. This option is available on TeleMetrum v2 and
- TeleMega boards. TeleMetrum v1 boards cannot transmit APRS
- packets. Note that a single APRS packet takes nearly a full
- second to transmit, so enabling this option will prevent
- sending any other telemetry during that time.
- </para>
- </section>
- <section>
- <title>APRS SSID</title>
- <para>
- Which SSID to report in APRS packets. By default, this is
- set to the last digit of the serial number, but can be
- configured to any value from 0 to 9.
- </para>
- </section>
- <section>
- <title>Callsign</title>
- <para>
- This sets the call sign included in each telemetry packet. Set this
- as needed to conform to your local radio regulations.
- </para>
- </section>
- <section>
- <title>Maximum Flight Log Size</title>
- <para>
- This sets the space (in kilobytes) allocated for each flight
- log. The available space will be divided into chunks of this
- size. A smaller value will allow more flights to be stored,
- a larger value will record data from longer flights.
- </para>
- </section>
- <section>
- <title>Ignitor Firing Mode</title>
- <para>
- This configuration parameter allows the two standard ignitor
- channels (Apogee and Main) to be used in different
- configurations.
- </para>
- <variablelist>
- <varlistentry>
- <term>Dual Deploy</term>
- <listitem>
- <para>
- This is the usual mode of operation; the
- 'apogee' channel is fired at apogee and the 'main'
- channel at the height above ground specified by the
- 'Main Deploy Altitude' during descent.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Redundant Apogee</term>
- <listitem>
- <para>
- This fires both channels at
- apogee, the 'apogee' channel first followed after a two second
- delay by the 'main' channel.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Redundant Main</term>
- <listitem>
- <para>
- This fires both channels at the
- height above ground specified by the Main Deploy
- Altitude setting during descent. The 'apogee'
- channel is fired first, followed after a two second
- delay by the 'main' channel.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- </section>
- <section>
- <title>Pad Orientation</title>
- <para>
- Because they include accelerometers, TeleMetrum,
- TeleMega and EasyMega are sensitive to the orientation of the board. By
- default, they expect the antenna end to point forward. This
- parameter allows that default to be changed, permitting the
- board to be mounted with the antenna pointing aft instead.
- </para>
- <variablelist>
- <varlistentry>
- <term>Antenna Up</term>
- <listitem>
- <para>
- In this mode, the antenna end of the
- flight computer must point forward, in line with the
- expected flight path.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Antenna Down</term>
- <listitem>
- <para>
- In this mode, the antenna end of the
- flight computer must point aft, in line with the
- expected flight path.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- </section>
- <section>
- <title>Beeper Frequency</title>
- <para>
- The beeper on all Altus Metrum flight computers works best
- at 4000Hz, however if you have more than one flight computer
- in a single airframe, having all of them sound at the same
- frequency can be confusing. This parameter lets you adjust
- the base beeper frequency value.
- </para>
- </section>
- <section>
- <title>Configure Pyro Channels</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="configure-pyro.png" width="6in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- This opens a separate window to configure the additional
- pyro channels available on TeleMega and EasyMega. One column is
- presented for each channel. Each row represents a single
- parameter, if enabled the parameter must meet the specified
- test for the pyro channel to be fired. See the Pyro Channels
- section in the System Operation chapter above for a
- description of these parameters.
- </para>
- <para>
- Select conditions and set the related value; the pyro
- channel will be activated when <emphasis>all</emphasis> of the
- conditions are met. Each pyro channel has a separate set of
- configuration values, so you can use different values for
- the same condition with different channels.
- </para>
- <para>
- At the bottom of the window, the 'Pyro Firing Time'
- configuration sets the length of time (in seconds) which
- each of these pyro channels will fire for.
- </para>
- <para>
- Once you have selected the appropriate configuration for all
- of the necessary pyro channels, you can save the pyro
- configuration along with the rest of the flight computer
- configuration by pressing the 'Save' button in the main
- Configure Flight Computer window.
- </para>
- </section>
- </section>
- <section>
- <title>Configure AltosUI</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="configure-altosui.png" width="2.4in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- This button presents a dialog so that you can configure the AltosUI global settings.
- </para>
- <section>
- <title>Voice Settings</title>
- <para>
- AltosUI provides voice announcements during flight so that you
- can keep your eyes on the sky and still get information about
- the current flight status. However, sometimes you don't want
- to hear them.
- </para>
- <variablelist>
- <varlistentry>
- <term>Enable</term>
- <listitem>
- <para>Turns all voice announcements on and off</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Test Voice</term>
- <listitem>
- <para>
- Plays a short message allowing you to verify
- that the audio system is working and the volume settings
- are reasonable
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- </section>
- <section>
- <title>Log Directory</title>
- <para>
- AltosUI logs all telemetry data and saves all TeleMetrum flash
- data to this directory. This directory is also used as the
- staring point when selecting data files for display or export.
- </para>
- <para>
- Click on the directory name to bring up a directory choosing
- dialog, select a new directory and click 'Select Directory' to
- change where AltosUI reads and writes data files.
- </para>
- </section>
- <section>
- <title>Callsign</title>
- <para>
- This value is transmitted in each command packet sent from
- TeleDongle and received from an altimeter. It is not used in
- telemetry mode, as the callsign configured in the altimeter board
- is included in all telemetry packets. Configure this
- with the AltosUI operators call sign as needed to comply with
- your local radio regulations.
- </para>
- <para>
- Note that to successfully command a flight computer over the radio
- (to configure the altimeter, monitor idle, or fire pyro charges),
- the callsign configured here must exactly match the callsign
- configured in the flight computer. This matching is case
- sensitive.
- </para>
- </section>
- <section>
- <title>Imperial Units</title>
- <para>
- This switches between metric units (meters) and imperial
- units (feet and miles). This affects the display of values
- use during flight monitoring, configuration, data graphing
- and all of the voice announcements. It does not change the
- units used when exporting to CSV files, those are always
- produced in metric units.
- </para>
- </section>
- <section>
- <title>Font Size</title>
- <para>
- Selects the set of fonts used in the flight monitor
- window. Choose between the small, medium and large sets.
- </para>
- </section>
- <section>
- <title>Serial Debug</title>
- <para>
- This causes all communication with a connected device to be
- dumped to the console from which AltosUI was started. If
- you've started it from an icon or menu entry, the output
- will simply be discarded. This mode can be useful to debug
- various serial communication issues.
- </para>
- </section>
- <section>
- <title>Manage Frequencies</title>
- <para>
- This brings up a dialog where you can configure the set of
- frequencies shown in the various frequency menus. You can
- add as many as you like, or even reconfigure the default
- set. Changing this list does not affect the frequency
- settings of any devices, it only changes the set of
- frequencies shown in the menus.
- </para>
- </section>
- </section>
- <section>
- <title>Configure Groundstation</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="configure-groundstation.png" width="3.1in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- Select this button and then select a TeleDongle or TeleBT Device from the list provided.
- </para>
- <para>
- The first few lines of the dialog provide information about the
- connected device, including the product name,
- software version and hardware serial number. Below that are the
- individual configuration entries.
- </para>
- <para>
- Note that TeleDongle and TeleBT don't save any configuration
- data, the settings here are recorded on the local machine in
- the Java preferences database. Moving the device to
- another machine, or using a different user account on the same
- machine will cause settings made here to have no effect.
- </para>
- <para>
- At the bottom of the dialog, there are three buttons:
- </para>
- <variablelist>
- <varlistentry>
- <term>Save</term>
- <listitem>
- <para>
- This writes any changes to the
- local Java preferences file. If you don't
- press this button, any changes you make will be lost.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Reset</term>
- <listitem>
- <para>
- This resets the dialog to the most recently saved values,
- erasing any changes you have made.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Close</term>
- <listitem>
- <para>
- This closes the dialog. Any unsaved changes will be
- lost.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- <para>
- The rest of the dialog contains the parameters to be configured.
- </para>
- <section>
- <title>Frequency</title>
- <para>
- This configures the frequency to use for both telemetry and
- packet command mode. Set this before starting any operation
- involving packet command mode so that it will use the right
- frequency. Telemetry monitoring mode also provides a menu to
- change the frequency, and that menu also sets the same Java
- preference value used here.
- </para>
- </section>
- <section>
- <title>RF Calibration</title>
- <para>
- The radios in every Altus Metrum device are calibrated at the
- factory to ensure that they transmit and receive on the
- specified frequency. To change a TeleDongle or TeleBT's calibration,
- you must reprogram the unit completely, so this entry simply
- shows the current value and doesn't allow any changes.
- </para>
- </section>
- <section>
- <title>Telemetry Rate</title>
- <para>
- This lets you match the telemetry and packet link rate from
- the transmitter. If they don't match, the device won't
- receive any data.
- </para>
- </section>
- </section>
- <section>
- <title>Flash Image</title>
- <para>
- This reprograms Altus Metrum devices with new
- firmware. TeleMetrum v1.x, TeleDongle v0.2, TeleMini and
- TeleBT are all reprogrammed by using another similar unit as a
- programming dongle (pair programming). TeleMega, EasyMega,
- TeleMetrum v2, EasyMini and TeleDongle v3 are all programmed
- directly over their USB ports (self programming). Please read
- the directions for flashing devices in the Updating Device
- Firmware chapter below.
- </para>
- </section>
- <section>
- <title>Fire Igniter</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="fire-igniter.png" width="1.2in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- This activates the igniter circuits in the flight computer to help
- test recovery systems deployment. Because this command can operate
- over the Packet Command Link, you can prepare the rocket as
- for flight and then test the recovery system without needing
- to snake wires inside the air-frame.
- </para>
- <para>
- Selecting the 'Fire Igniter' button brings up the usual device
- selection dialog. Pick the desired device. This brings up another
- window which shows the current continuity test status for all
- of the pyro channels.
- </para>
- <para>
- Next, select the desired igniter to fire. This will enable the
- 'Arm' button.
- </para>
- <para>
- Select the 'Arm' button. This enables the 'Fire' button. The
- word 'Arm' is replaced by a countdown timer indicating that
- you have 10 seconds to press the 'Fire' button or the system
- will deactivate, at which point you start over again at
- selecting the desired igniter.
- </para>
- </section>
- <section>
- <title>Scan Channels</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="scan-channels.png" width="3.2in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- This listens for telemetry packets on all of the configured
- frequencies, displaying information about each device it
- receives a packet from. You can select which of the baud rates
- and telemetry formats should be tried; by default, it only listens
- at 38400 baud with the standard telemetry format used in v1.0 and later
- firmware.
- </para>
- </section>
- <section>
- <title>Load Maps</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="load-maps.png" width="5.2in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- Before heading out to a new launch site, you can use this to
- load satellite images in case you don't have internet
- connectivity at the site.
- </para>
- <para>
- There's a drop-down menu of launch sites we know about; if
- your favorites aren't there, please let us know the lat/lon
- and name of the site. The contents of this list are actually
- downloaded from our server at run-time, so as new sites are sent
- in, they'll get automatically added to this list.
- If the launch site isn't in the list, you can manually enter the lat/lon values
- </para>
- <para>
- There are four different kinds of maps you can view; you can
- select which to download by selecting as many as you like from
- the available types:
- <variablelist>
- <varlistentry>
- <term>Hybrid</term>
- <listitem>
- <para>
- A combination of satellite imagery and road data. This
- is the default view.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Satellite</term>
- <listitem>
- <para>
- Just the satellite imagery without any annotation.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Roadmap</term>
- <listitem>
- <para>
- Roads, political boundaries and a few geographic features.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Terrain</term>
- <listitem>
- <para>
- Contour intervals and shading that show hills and
- valleys.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- </para>
- <para>
- You can specify the range of zoom levels to download; smaller
- numbers show more area with less resolution. The default
- level, 0, shows about 3m/pixel. One zoom level change
- doubles or halves that number. Larger zoom levels show more
- detail, smaller zoom levels less.
- </para>
- <para>
- The Map Radius value sets how large an area around the center
- point to download. Select a value large enough to cover any
- plausible flight from that site. Be aware that loading a large
- area with a high maximum zoom level can attempt to download a
- lot of data. Loading hybrid maps with a 10km radius at a
- minimum zoom of -2 and a maximum zoom of 2 consumes about
- 120MB of space. Terrain and road maps consume about 1/10 as
- much space as satellite or hybrid maps.
- </para>
- <para>
- Clicking the 'Load Map' button will fetch images from Google
- Maps; note that Google limits how many images you can fetch at
- once, so if you load more than one launch site, you may get
- some gray areas in the map which indicate that Google is tired
- of sending data to you. Try again later.
- </para>
- </section>
- <section>
- <title>Monitor Idle</title>
- <informalfigure>
- <mediaobject>
- <imageobject>
- <imagedata fileref="monitor-idle.png" width="5.2in" scalefit="1"/>
- </imageobject>
- </mediaobject>
- </informalfigure>
- <para>
- This brings up a dialog similar to the Monitor Flight UI,
- except it works with the altimeter in “idle” mode by sending
- query commands to discover the current state rather than
- listening for telemetry packets. Because this uses command
- mode, it needs to have the TeleDongle and flight computer
- callsigns match exactly. If you can receive telemetry, but
- cannot manage to run Monitor Idle, then it's very likely that
- your callsigns are different in some way.
- </para>
- <para>
- You can change the frequency and callsign used to communicate
- with the flight computer; they must both match the
- configuration in the flight computer exactly.
- </para>
- </section>
- </chapter>
- <chapter>
- <title>AltosDroid</title>
- <para>
- AltosDroid provides the same flight monitoring capabilities as
- AltosUI, but runs on Android devices. AltosDroid is designed to connect
- to a TeleBT receiver over Bluetooth™ and (on Android devices supporting
- USB On-the-go) TeleDongle and TeleBT devices over USB. AltosDroid monitors
- telemetry data, logging it to internal storage in the Android
- device, and presents that data in a UI similar to the 'Monitor
- Flight' window in AltosUI.
- </para>
- <para>
- This manual will explain how to configure AltosDroid, connect to
- TeleBT or TeleDongle, operate the flight monitoring interface
- and describe what the displayed data means.
- </para>
- <section>
- <title>Installing AltosDroid</title>
- <para>
- AltosDroid is available from the Google Play store. To install
- it on your Android device, open the Google Play Store
- application and search for “altosdroid”. Make sure you don't
- have a space between “altos” and “droid” or you probably won't
- find what you want. That should bring you to the right page
- from which you can download and install the application.
- </para>
- </section>
- <section>
- <title>Charging TeleBT Battery</title>
- <para>
- Before using TeleBT with AltosDroid, make sure the internal
- TeleBT battery is charged. To do this, attach a micro USB
- cable from a computer or other USB power source to TeleBT.
- A dual LED on the circuit board should illuminate, showing
- red while the battery is charging, green when charging is
- completed, and both red and green on at the same time if
- there is a battery fault.
- </para>
- </section>
- <section>
- <title>Connecting to TeleBT over Bluetooth™</title>
- <para>
- Press the Android 'Menu' button or soft-key to see the
- configuration options available. Select the 'Connect a device'
- option and then the 'Scan for devices' entry at the bottom to
- look for your TeleBT device. Select your device, and when it
- asks for the code, enter '1234'.
- </para>
- <para>
- Subsequent connections will not require you to enter that
- code, and your 'paired' device will appear in the list without
- scanning.
- </para>
- </section>
- <section>
- <title>Connecting to TeleDongle or TeleBT over USB</title>
- <para>
- Get a special USB On-the-go adapter cable. These cables have a USB
- micro-B male connector on one end and a standard A female
- connector on the other end. Plug in your TeleDongle or TeleBT
- device to the adapter cable and the adapter cable into your
- phone and AltosDroid should automatically start up. If it
- doesn't, the most likely reason is that your Android device
- doesn't support USB On-the-go.
- </para>
- </section>
- <section>
- <title>Configuring AltosDroid</title>
- <para>
- There are several configuration and operation parameters
- available in the AltosDroid menu.
- </para>
- <section>
- <title>Select radio frequency</title>
- <para>
- This selects which frequency to listen on by bringing up a
- menu of pre-set radio frequencies. Pick the one which matches
- your altimeter.
- </para>
- </section>
- <section>
- <title>Select data rate</title>
- <para>
- Altus Metrum transmitters can be configured to operate at
- lower data rates to improve transmission range. If you have
- configured your device to do this, this menu item allows you
- to change the receiver to match.
- </para>
- </section>
- <section>
- <title>Change units</title>
- <para>
- This toggles between metric and imperial units.
- </para>
- </section>
- <section>
- <title>Load maps</title>
- <para>
- Brings up a dialog allowing you to download offline map
- tiles so that you can have maps available even if you have
- no network connectivity at the launch site.
- </para>
- </section>
- <section>
- <title>Map type</title>
- <para>
- Displays a menu of map types and lets you select one. Hybrid
- maps include satellite images with a roadmap
- overlaid. Satellite maps dispense with the roadmap
- overlay. Roadmap shows just the roads. Terrain includes
- roads along with shadows indicating changes in elevation,
- and other geographical features.
- </para>
- </section>
- <section>
- <title>Toggle Online/Offline maps</title>
- <para>
- Switches between online and offline maps. Online maps will
- show a 'move to current position' icon in the upper right
- corner, while offline maps will have copyright information
- all over the map. Otherwise, they're pretty similar.
- </para>
- </section>
- <section>
- <title>Select Tracker</title>
- <para>
- Switches the information displays to show data for a
- different transmitting device. The map will always show all
- of the devices in view. Trackers are shown and selected by
- serial number, so make sure you note the serial number of
- devices in each airframe.
- </para>
- </section>
- <section>
- <title>Delete Track</title>
- <para>
- Deletes all information about a transmitting device.
- </para>
- </section>
- </section>
- <section>
- <title>AltosDroid Flight Monitoring</title>
- <para>
- AltosDroid is designed to mimic the AltosUI flight monitoring
- display, providing separate tabs for each stage of your rocket
- flight along with a tab containing a map of the local area
- with icons marking the current location of the altimeter and
- the Android device.
- </para>
- <section>
- <title>Pad</title>
- <para>
- The 'Pad' tab shows information used to decide when the
- rocket is ready for flight. The first elements include red/green
- indicators, if any of these is red, you'll want to evaluate
- whether the rocket is ready to launch.
- </para>
- <para>
- When the pad tab is selected, the voice responses will
- include status changes to the igniters and GPS reception,
- letting you know if the rocket is still ready for launch.
- </para>
- <variablelist>
- <varlistentry>
- <term>Battery</term>
- <listitem>
- <para>
- This indicates whether the Li-Po battery
- powering the transmitter has sufficient charge to last for
- the duration of the flight. A value of more than
- 3.8V is required for a 'GO' status.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Receiver Battery</term>
- <listitem>
- <para>
- This indicates whether the Li-Po battery
- powering the TeleBT has sufficient charge to last for
- the duration of the flight. A value of more than
- 3.8V is required for a 'GO' status.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Data Logging</term>
- <listitem>
- <para>
- This indicates whether there is space remaining
- on-board to store flight data for the upcoming
- flight. If you've downloaded data, but failed to
- erase flights, there may not be any space
- left. TeleMetrum and TeleMega can store multiple
- flights, depending on the configured maximum flight
- log size. TeleGPS logs data continuously. TeleMini
- stores only a single flight, so it will need to be
- downloaded and erased after each flight to capture
- data. This only affects on-board flight logging; the
- altimeter will still transmit telemetry and fire
- ejection charges at the proper times.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>GPS Locked</term>
- <listitem>
- <para>
- For a TeleMetrum or TeleMega device, this indicates whether the GPS receiver is
- currently able to compute position information. GPS requires
- at least 4 satellites to compute an accurate position.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>GPS Ready</term>
- <listitem>
- <para>
- For a TeleMetrum or TeleMega device, this indicates whether GPS has reported at least
- 10 consecutive positions without losing lock. This ensures
- that the GPS receiver has reliable reception from the
- satellites.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Apogee Igniter</term>
- <listitem>
- <para>
- This indicates whether the apogee
- igniter has continuity. If the igniter has a low
- resistance, then the voltage measured here will be close
- to the Li-Po battery voltage. A value greater than 3.2V is
- required for a 'GO' status.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Main Igniter</term>
- <listitem>
- <para>
- This indicates whether the main
- igniter has continuity. If the igniter has a low
- resistance, then the voltage measured here will be close
- to the Li-Po battery voltage. A value greater than 3.2V is
- required for a 'GO' status.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Igniter A-D</term>
- <listitem>
- <para>
- This indicates whether the indicated additional pyro
- channel igniter has continuity. If the igniter has a
- low resistance, then the voltage measured here will
- be close to the Li-Po battery voltage. A value
- greater than 3.2V is required for a 'GO' status.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- <para>
- The Pad tab also shows the location of the Android device.
- </para>
- </section>
- <section>
- <title>Flight</title>
- <para>
- The 'Flight' tab shows information used to evaluate and spot
- a rocket while in flight. It displays speed and height data
- to monitor the health of the rocket, along with elevation,
- range and bearing to help locate the rocket in the sky.
- </para>
- <para>
- While the Flight tab is displayed, the voice announcements
- will include current speed, height, elevation and bearing
- information.
- </para>
- <variablelist>
- <varlistentry>
- <term>Speed</term>
- <listitem>
- <para>
- Shows current vertical speed. During descent, the
- speed values are averaged over a fairly long time to
- try and make them steadier.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Height</term>
- <listitem>
- <para>
- Shows the current height above the launch pad.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Max Speed</term>
- <listitem>
- <para>
- Shows the maximum vertical speed seen during the flight.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Max Height</term>
- <listitem>
- <para>
- Shows the maximum height above launch pad.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Elevation</term>
- <listitem>
- <para>
- This is the angle above the horizon from the android
- devices current position.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Range</term>
- <listitem>
- <para>
- The total distance from the android device to the
- rocket, including both ground distance and
- difference in altitude. Use this to gauge how large
- the rocket is likely to appear in the sky.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Bearing</term>
- <listitem>
- <para>
- This is the aziumuth from true north for the rocket
- from the android device. Use this in combination
- with the Elevation value to help locate the rocket
- in the sky, or at least to help point the antenna in
- the general direction. This is provided in both
- degrees and a compass point (like West South
- West). You'll want to know which direction is true
- north before launching your rocket.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Ground Distance</term>
- <listitem>
- <para>
- This shows the distance across the ground to the
- lat/lon where the rocket is located. Use this to
- estimate what is currently under the rocket.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Latitude/Longitude</term>
- <listitem>
- <para>
- Displays the last known location of the rocket.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Apogee Igniter</term>
- <listitem>
- <para>
- This indicates whether the apogee
- igniter has continuity. If the igniter has a low
- resistance, then the voltage measured here will be close
- to the Li-Po battery voltage. A value greater than 3.2V is
- required for a 'GO' status.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Main Igniter</term>
- <listitem>
- <para>
- This indicates whether the main
- igniter has continuity. If the igniter has a low
- resistance, then the voltage measured here will be close
- to the Li-Po battery voltage. A value greater than 3.2V is
- required for a 'GO' status.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- </section>
- <section>
- <title>Recover</title>
- <para>
- The 'Recover' tab shows information used while recovering the
- rocket on the ground after flight.
- </para>
- <para>
- While the Recover tab is displayed, the voice announcements
- will include distance along with either bearing or
- direction, depending on whether you are moving.
- </para>
- <variablelist>
- <varlistentry>
- <term>Bearing</term>
- <listitem>
- <para>
- This is the aziumuth from true north for the rocket
- from the android device. Use this in combination
- with the Elevation value to help locate the rocket
- in the sky, or at least to help point the antenna in
- the general direction. This is provided in both
- degrees and a compass point (like West South
- West). You'll want to know which direction is true
- north before launching your rocket.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Direction</term>
- <listitem>
- <para>
- When you are in motion, this provides the angle from
- your current direction of motion towards the rocket.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Distance</term>
- <listitem>
- <para>
- Distance over the ground to the rocket.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Tar Lat/Tar Lon</term>
- <listitem>
- <para>
- Displays the last known location of the rocket.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>My Lat/My Lon</term>
- <listitem>
- <para>
- Displays the location of the Android device.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Max Height</term>
- <listitem>
- <para>
- Shows the maximum height above launch pad.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Max Speed</term>
- <listitem>
- <para>
- Shows the maximum vertical speed seen during the flight.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>Max Accel</term>
- <listitem>
- <para>
- Shows the maximum vertical acceleration seen during the flight.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- </section>
- <section>
- <title>Map</title>
- <para>
- The 'Map' tab shows a map of the area around the rocket
- being tracked along with information needed to recover it.
- </para>
- <para>
- On the map itself, icons showing the location of the android
- device along with the last known location of each tracker. A
- blue line is drawn from the android device location to the
- currently selected tracker.
- </para>
- <para>
- Below the map, the distance and either bearing or direction
- along with the lat/lon of the target and the android device
- are shown
- </para>
- <para>
- The Map tab provides the same voice announcements as the
- Recover tab.
- </para>
- </section>
- </section>
- <section>
- <title>Downloading Flight Logs</title>
- <para>
- AltosDroid always saves every bit of telemetry data it
- receives. To download that to a computer for use with AltosUI,
- remove the SD card from your Android device, or connect your
- device to your computer's USB port and browse the files on
- that device. You will find '.telem' files in the TeleMetrum
- directory that will work with AltosUI directly.
- </para>
- </section>
- </chapter>
- <chapter>
- <title>Using Altus Metrum Products</title>
- <section>
- <title>Being Legal</title>
- <para>
- First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
- other authorization to legally operate the radio transmitters that are part
- of our products.
- </para>
- </section>
- <section>
- <title>In the Rocket</title>
- <para>
- In the rocket itself, you just need a flight computer and
- a single-cell, 3.7 volt nominal Li-Po rechargeable battery. An
- 850mAh battery weighs less than a 9V alkaline battery, and will
- run a TeleMetrum, TeleMega or EasyMega for hours.
- A 110mAh battery weighs less than a triple A battery and is a good
- choice for use with TeleMini or EasyMini.
- </para>
- <para>
- By default, we ship TeleMini, TeleMetrum and TeleMega flight computers with a simple wire antenna.
- If your electronics bay or the air-frame it resides within is made
- of carbon fiber, which is opaque to RF signals, you may prefer to
- install an SMA connector so that you can run a coaxial cable to an
- antenna mounted elsewhere in the rocket. However, note that the
- GPS antenna is fixed on all current products, so you really want
- to install the flight computer in a bay made of RF-transparent
- materials if at all possible.
- </para>
- </section>
- <section>
- <title>On the Ground</title>
- <para>
- To receive the data stream from the rocket, you need an antenna and short
- feed-line connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> units. If possible, use an SMA to BNC
- adapter instead of feedline between the antenna feedpoint and
- TeleDongle, as this will give you the best performance. The
- TeleDongle in turn plugs directly into the USB port on a notebook
- computer. Because TeleDongle looks like a simple serial port, your computer
- does not require special device drivers... just plug it in.
- </para>
- <para>
- The GUI tool, AltosUI, is written in Java and runs across
- Linux, Mac OS and Windows. There's also a suite of C tools
- for Linux which can perform most of the same tasks.
- </para>
- <para>
- Alternatively, a TeleBT attached with an SMA to BNC adapter at the
- feed point of a hand-held yagi used in conjunction with an Android
- device running AltosDroid makes an outstanding ground station.
- </para>
- <para>
- After the flight, you can use the radio link to extract the more detailed data
- logged in either TeleMetrum or TeleMini devices, or you can use a mini USB cable to plug into the
- TeleMetrum board directly. Pulling out the data without having to open up
- the rocket is pretty cool! A USB cable is also how you charge the Li-Po
- battery, so you'll want one of those anyway... the same cable used by lots
- of digital cameras and other modern electronic stuff will work fine.
- </para>
- <para>
- If your rocket lands out of sight, you may enjoy having a hand-held
- GPS receiver, so that you can put in a way-point for the last
- reported rocket position before touch-down. This makes looking for
- your rocket a lot like Geo-Caching... just go to the way-point and
- look around starting from there. AltosDroid on an Android device
- with GPS receiver works great for this, too!
- </para>
- <para>
- You may also enjoy having a ham radio “HT” that covers the 70cm band... you
- can use that with your antenna to direction-find the rocket on the ground
- the same way you can use a Walston or Beeline tracker. This can be handy
- if the rocket is hiding in sage brush or a tree, or if the last GPS position
- doesn't get you close enough because the rocket dropped into a canyon, or
- the wind is blowing it across a dry lake bed, or something like that... Keith
- currently uses a Yaesu FT1D, Bdale has a Yaesu VX-7R, which
- is a nicer radio in most ways but doesn't support APRS.
- </para>
- <para>
- So, to recap, on the ground the hardware you'll need includes:
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- <para>
- an antenna and feed-line or adapter
- </para>
- </listitem>
- <listitem>
- <para>
- a TeleDongle
- </para>
- </listitem>
- <listitem>
- <para>
- a notebook computer
- </para>
- </listitem>
- <listitem>
- <para>
- optionally, a hand-held GPS receiver
- </para>
- </listitem>
- <listitem>
- <para>
- optionally, an HT or receiver covering 435 MHz
- </para>
- </listitem>
- </orderedlist>
- </para>
- <para>
- The best hand-held commercial directional antennas we've found for radio
- direction finding rockets are from
- <ulink url="http://www.arrowantennas.com/" >
- Arrow Antennas.
- </ulink>
- The 440-3 and 440-5 are both good choices for finding a
- TeleMetrum- or TeleMini- equipped rocket when used with a suitable
- 70cm HT. TeleDongle and an SMA to BNC adapter fit perfectly
- between the driven element and reflector of Arrow antennas.
- </para>
- </section>
- <section>
- <title>Data Analysis</title>
- <para>
- Our software makes it easy to log the data from each flight, both the
- telemetry received during the flight itself, and the more
- complete data log recorded in the flash memory on the altimeter
- board. Once this data is on your computer, our post-flight tools make it
- easy to quickly get to the numbers everyone wants, like apogee altitude,
- max acceleration, and max velocity. You can also generate and view a
- standard set of plots showing the altitude, acceleration, and
- velocity of the rocket during flight. And you can even export a TeleMetrum data file
- usable with Google Maps and Google Earth for visualizing the flight path
- in two or three dimensions!
- </para>
- <para>
- Our ultimate goal is to emit a set of files for each flight that can be
- published as a web page per flight, or just viewed on your local disk with
- a web browser.
- </para>
- </section>
- <section>
- <title>Future Plans</title>
- <para>
- We have designed and prototyped several “companion boards” that
- can attach to the companion connector on TeleMetrum,
- TeleMega and EasyMega
- flight computers to collect more data, provide more pyro channels,
- and so forth. We do not yet know if or when any of these boards
- will be produced in enough quantity to sell. If you have specific
- interests for data collection or control of events in your rockets
- beyond the capabilities of our existing productions, please let
- us know!
- </para>
- <para>
- Because all of our work is open, both the hardware designs and the
- software, if you have some great idea for an addition to the current
- Altus Metrum family, feel free to dive in and help! Or let us know
- what you'd like to see that we aren't already working on, and maybe
- we'll get excited about it too...
- </para>
- <para>
- Watch our
- <ulink url="http://altusmetrum.org/">web site</ulink> for more news
- and information as our family of products evolves!
- </para>
- </section>
- </chapter>
- <chapter>
- <title>Altimeter Installation Recommendations</title>
- <para>
- Building high-power rockets that fly safely is hard enough. Mix
- in some sophisticated electronics and a bunch of radio energy
- and some creativity and/or compromise may be required. This chapter
- contains some suggestions about how to install Altus Metrum
- products into a rocket air-frame, including how to safely and
- reliably mix a variety of electronics into the same air-frame.
- </para>
- <section>
- <title>Mounting the Altimeter</title>
- <para>
- The first consideration is to ensure that the altimeter is
- securely fastened to the air-frame. For most of our products, we
- prefer nylon standoffs and nylon screws; they're good to at least 50G
- and cannot cause any electrical issues on the board. Metal screws
- and standoffs are fine, too, just be careful to avoid electrical
- shorts! For TeleMini v1.0, we usually cut small pieces of 1/16 inch
- balsa to fit
- under the screw holes, and then take 2x56 nylon screws and
- screw them through the TeleMini mounting holes, through the
- balsa and into the underlying material.
- </para>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- <para>
- Make sure accelerometer-equipped products like TeleMetrum,
- TeleMega and EasyMega are aligned precisely along the axis of
- acceleration so that the accelerometer can accurately
- capture data during the flight.
- </para>
- </listitem>
- <listitem>
- <para>
- Watch for any metal touching components on the
- board. Shorting out connections on the bottom of the board
- can cause the altimeter to fail during flight.
- </para>
- </listitem>
- </orderedlist>
- </section>
- <section>
- <title>Dealing with the Antenna</title>
- <para>
- The antenna supplied is just a piece of solid, insulated,
- wire. If it gets damaged or broken, it can be easily
- replaced. It should be kept straight and not cut; bending or
- cutting it will change the resonant frequency and/or
- impedance, making it a less efficient radiator and thus
- reducing the range of the telemetry signal.
- </para>
- <para>
- Keeping metal away from the antenna will provide better range
- and a more even radiation pattern. In most rockets, it's not
- entirely possible to isolate the antenna from metal
- components; there are often bolts, all-thread and wires from other
- electronics to contend with. Just be aware that the more stuff
- like this around the antenna, the lower the range.
- </para>
- <para>
- Make sure the antenna is not inside a tube made or covered
- with conducting material. Carbon fiber is the most common
- culprit here -- CF is a good conductor and will effectively
- shield the antenna, dramatically reducing signal strength and
- range. Metallic flake paint is another effective shielding
- material which should be avoided around any antennas.
- </para>
- <para>
- If the ebay is large enough, it can be convenient to simply
- mount the altimeter at one end and stretch the antenna out
- inside. Taping the antenna to the sled can keep it straight
- under acceleration. If there are metal rods, keep the
- antenna as far away as possible.
- </para>
- <para>
- For a shorter ebay, it's quite practical to have the antenna
- run through a bulkhead and into an adjacent bay. Drill a small
- hole in the bulkhead, pass the antenna wire through it and
- then seal it up with glue or clay. We've also used acrylic
- tubing to create a cavity for the antenna wire. This works a
- bit better in that the antenna is known to stay straight and
- not get folded by recovery components in the bay. Angle the
- tubing towards the side wall of the rocket and it ends up
- consuming very little space.
- </para>
- <para>
- If you need to place the UHF antenna at a distance from the
- altimeter, you can replace the antenna with an edge-mounted
- SMA connector, and then run 50Ω coax from the board to the
- antenna. Building a remote antenna is beyond the scope of this
- manual.
- </para>
- </section>
- <section>
- <title>Preserving GPS Reception</title>
- <para>
- The GPS antenna and receiver used in TeleMetrum and TeleMega is
- highly sensitive and normally have no trouble tracking enough
- satellites to provide accurate position information for
- recovering the rocket. However, there are many ways the GPS signal
- can end up attenuated, negatively affecting GPS performance.
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- <para>
- Conductive tubing or coatings. Carbon fiber and metal
- tubing, or metallic paint will all dramatically attenuate the
- GPS signal. We've never heard of anyone successfully
- receiving GPS from inside these materials.
- </para>
- </listitem>
- <listitem>
- <para>
- Metal components near the GPS patch antenna. These will
- de-tune the patch antenna, changing the resonant frequency
- away from the L1 carrier and reduce the effectiveness of the
- antenna. You can place as much stuff as you like beneath the
- antenna as that's covered with a ground plane. But, keep
- wires and metal out from above the patch antenna.
- </para>
- </listitem>
- </orderedlist>
- </para>
- </section>
- <section>
- <title>Radio Frequency Interference</title>
- <para>
- Any altimeter will generate RFI; the digital circuits use
- high-frequency clocks that spray radio interference across a
- wide band. Altus Metrum altimeters generate intentional radio
- signals as well, increasing the amount of RF energy around the board.
- </para>
- <para>
- Rocketry altimeters also use precise sensors measuring air
- pressure and acceleration. Tiny changes in voltage can cause
- these sensor readings to vary by a huge amount. When the
- sensors start mis-reporting data, the altimeter can either
- fire the igniters at the wrong time, or not fire them at all.
- </para>
- <para>
- Voltages are induced when radio frequency energy is
- transmitted from one circuit to another. Here are things that
- influence the induced voltage and current:
- </para>
- <itemizedlist>
- <listitem>
- <para>
- Keep wires from different circuits apart. Moving circuits
- further apart will reduce RFI.
- </para>
- </listitem>
- <listitem>
- <para>
- Avoid parallel wires from different circuits. The longer two
- wires run parallel to one another, the larger the amount of
- transferred energy. Cross wires at right angles to reduce
- RFI.
- </para>
- </listitem>
- <listitem>
- <para>
- Twist wires from the same circuits. Two wires the same
- distance from the transmitter will get the same amount of
- induced energy which will then cancel out. Any time you have
- a wire pair running together, twist the pair together to
- even out distances and reduce RFI. For altimeters, this
- includes battery leads, switch hookups and igniter
- circuits.
- </para>
- </listitem>
- <listitem>
- <para>
- Avoid resonant lengths. Know what frequencies are present
- in the environment and avoid having wire lengths near a
- natural resonant length. Altus Metrum products transmit on the
- 70cm amateur band, so you should avoid lengths that are a
- simple ratio of that length; essentially any multiple of ¼
- of the wavelength (17.5cm).
- </para>
- </listitem>
- </itemizedlist>
- </section>
- <section>
- <title>The Barometric Sensor</title>
- <para>
- Altusmetrum altimeters measure altitude with a barometric
- sensor, essentially measuring the amount of air above the
- rocket to figure out how high it is. A large number of
- measurements are taken as the altimeter initializes itself to
- figure out the pad altitude. Subsequent measurements are then
- used to compute the height above the pad.
- </para>
- <para>
- To accurately measure atmospheric pressure, the ebay
- containing the altimeter must be vented outside the
- air-frame. The vent must be placed in a region of linear
- airflow, have smooth edges, and away from areas of increasing or
- decreasing pressure.
- </para>
- <para>
- All barometric sensors are quite sensitive to chemical damage from
- the products of APCP or BP combustion, so make sure the ebay is
- carefully sealed from any compartment which contains ejection
- charges or motors.
- </para>
- </section>
- <section>
- <title>Ground Testing</title>
- <para>
- The most important aspect of any installation is careful
- ground testing. Bringing an air-frame up to the LCO table which
- hasn't been ground tested can lead to delays or ejection
- charges firing on the pad, or, even worse, a recovery system
- failure.
- </para>
- <para>
- Do a 'full systems' test that includes wiring up all igniters
- without any BP and turning on all of the electronics in flight
- mode. This will catch any mistakes in wiring and any residual
- RFI issues that might accidentally fire igniters at the wrong
- time. Let the air-frame sit for several minutes, checking for
- adequate telemetry signal strength and GPS lock. If any igniters
- fire unexpectedly, find and resolve the issue before loading any
- BP charges!
- </para>
- <para>
- Ground test the ejection charges. Prepare the rocket for
- flight, loading ejection charges and igniters. Completely
- assemble the air-frame and then use the 'Fire Igniters'
- interface through a TeleDongle to command each charge to
- fire. Make sure the charge is sufficient to robustly separate
- the air-frame and deploy the recovery system.
- </para>
- </section>
- </chapter>
- <chapter>
- <title>Updating Device Firmware</title>
- <para>
- TeleMega, TeleMetrum v2, EasyMega, EasyMini and TeleDongle v3
- are all programmed directly over their USB connectors (self
- programming). TeleMetrum v1, TeleMini and TeleDongle v0.2 are
- all programmed by using another device as a programmer (pair
- programming). It's important to recognize which kind of devices
- you have before trying to reprogram them.
- </para>
- <para>
- You may wish to begin by ensuring you have current firmware images.
- These are distributed as part of the AltOS software bundle that
- also includes the AltosUI ground station program. Newer ground
- station versions typically work fine with older firmware versions,
- so you don't need to update your devices just to try out new
- software features. You can always download the most recent
- version from <ulink url="http://www.altusmetrum.org/AltOS/"/>.
- </para>
- <para>
- If you need to update the firmware on a TeleDongle v0.2, we recommend
- updating the altimeter first, before updating TeleDongle. However,
- note that TeleDongle rarely need to be updated. Any firmware version
- 1.0.1 or later will work, version 1.2.1 may have improved receiver
- performance slightly.
- </para>
- <para>
- Self-programmable devices (TeleMega, TeleMetrum v2, EasyMega and EasyMini)
- are reprogrammed by connecting them to your computer over USB
- </para>
- <section>
- <title>
- Updating TeleMega, TeleMetrum v2, EasyMega, EasyMini or
- TeleDongle v3 Firmware
- </title>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- <para>
- Attach a battery if necessary and power switch to the target
- device. Power up the device.
- </para>
- </listitem>
- <listitem>
- <para>
- Using a Micro USB cable, connect the target device to your
- computer's USB socket.
- </para>
- </listitem>
- <listitem>
- <para>
- Run AltosUI, and select 'Flash Image' from the File menu.
- </para>
- </listitem>
- <listitem>
- <para>
- Select the target device in the Device Selection dialog.
- </para>
- </listitem>
- <listitem>
- <para>
- Select the image you want to flash to the device, which
- should have a name in the form
- <product>-v<product-version>-<software-version>.ihx, such
- as TeleMega-v1.0-1.3.0.ihx.
- </para>
- </listitem>
- <listitem>
- <para>
- Make sure the configuration parameters are reasonable
- looking. If the serial number and/or RF configuration
- values aren't right, you'll need to change them.
- </para>
- </listitem>
- <listitem>
- <para>
- Hit the 'OK' button and the software should proceed to flash
- the device with new firmware, showing a progress bar.
- </para>
- </listitem>
- <listitem>
- <para>
- Verify that the device is working by using the 'Configure
- Altimeter' or 'Configure Groundstation' item to check over
- the configuration.
- </para>
- </listitem>
- </orderedlist>
- <section>
- <title>Recovering From Self-Flashing Failure</title>
- <para>
- If the firmware loading fails, it can leave the device
- unable to boot. Not to worry, you can force the device to
- start the boot loader instead, which will let you try to
- flash the device again.
- </para>
- <para>
- On each device, connecting two pins from one of the exposed
- connectors will force the boot loader to start, even if the
- regular operating system has been corrupted in some way.
- </para>
- <variablelist>
- <varlistentry>
- <term>TeleMega</term>
- <listitem>
- <para>
- Connect pin 6 and pin 1 of the companion connector. Pin 1
- can be identified by the square pad around it, and then
- the pins could sequentially across the board. Be very
- careful to <emphasis>not</emphasis> short pin 8 to
- anything as that is connected directly to the battery. Pin
- 7 carries 3.3V and the board will crash if that is
- connected to pin 1, but shouldn't damage the board.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>EasyMega</term>
- <listitem>
- <para>
- Connect pin 6 and pin 1 of the companion connector. Pin 1
- can be identified by the square pad around it, and then
- the pins could sequentially across the board. Be very
- careful to <emphasis>not</emphasis> short pin 8 to
- anything as that is connected directly to the battery. Pin
- 7 carries 3.3V and the board will crash if that is
- connected to pin 1, but shouldn't damage the board.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>TeleMetrum v2</term>
- <listitem>
- <para>
- Connect pin 6 and pin 1 of the companion connector. Pin 1
- can be identified by the square pad around it, and then
- the pins could sequentially across the board. Be very
- careful to <emphasis>not</emphasis> short pin 8 to
- anything as that is connected directly to the battery. Pin
- 7 carries 3.3V and the board will crash if that is
- connected to pin 1, but shouldn't damage the board.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>EasyMini</term>
- <listitem>
- <para>
- Connect pin 6 and pin 1 of the debug connector, which is
- the six holes next to the beeper. Pin 1 can be identified
- by the square pad around it, and then the pins could
- sequentially across the board, making Pin 6 the one on the
- other end of the row.
- </para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term>TeleDongle v3</term>
- <listitem>
- <para>
- Connect pin 32 on the CPU to ground. Pin 32 is closest
- to the USB wires on the row of pins towards the center
- of the board. Ground is available on the capacitor
- next to it, on the end towards the USB wires.
- </para>
- </listitem>
- </varlistentry>
- </variablelist>
- <para>
- Once you've located the right pins:
- </para>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- <para>
- Turn the altimeter power off.
- </para>
- </listitem>
- <listitem>
- <para>
- Connect a battery.
- </para>
- </listitem>
- <listitem>
- <para>
- Connect the indicated terminals together with a short
- piece of wire. Take care not to accidentally connect
- anything else.
- </para>
- </listitem>
- <listitem>
- <para>
- Connect USB
- </para>
- </listitem>
- <listitem>
- <para>
- Turn the board power on.
- </para>
- </listitem>
- <listitem>
- <para>
- The board should now be visible over USB as 'AltosFlash'
- and be ready to receive firmware.
- </para>
- </listitem>
- <listitem>
- <para>
- Once the board has been powered up, you can remove the
- piece of wire.
- </para>
- </listitem>
- </orderedlist>
- </section>
- </section>
- <section>
- <title>Pair Programming</title>
- <para>
- The big concept to understand is that you have to use a
- TeleMetrum v1.0, TeleBT v1.0 or TeleDongle v0.2 as a
- programmer to update a pair programmed device. Due to limited
- memory resources in the cc1111, we don't support programming
- directly over USB for these devices.
- </para>
- </section>
- <section>
- <title>Updating TeleMetrum v1.x Firmware</title>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- <para>
- Find the 'programming cable' that you got as part of the starter
- kit, that has a red 8-pin MicroMaTch connector on one end and a
- red 4-pin MicroMaTch connector on the other end.
- </para>
- </listitem>
- <listitem>
- <para>
- Take the 2 screws out of the TeleDongle v0.2 or TeleBT v1.0
- case to get access to the circuit board.
- </para>
- </listitem>
- <listitem>
- <para>
- Plug the 8-pin end of the programming cable to the
- matching connector on the TeleDongle v0.2 or TeleBT v1.0, and the 4-pin end to the
- matching connector on the TeleMetrum.
- Note that each MicroMaTch connector has an alignment pin that
- goes through a hole in the PC board when you have the cable
- oriented correctly.
- </para>
- </listitem>
- <listitem>
- <para>
- Attach a battery to the TeleMetrum board.
- </para>
- </listitem>
- <listitem>
- <para>
- Plug the TeleDongle v0.2 or TeleBT v1.0 into your computer's USB port, and power
- up the TeleMetrum.
- </para>
- </listitem>
- <listitem>
- <para>
- Run AltosUI, and select 'Flash Image' from the File menu.
- </para>
- </listitem>
- <listitem>
- <para>
- Pick the TeleDongle v0.2 or TeleBT v1.0 device from the list, identifying it as the
- programming device.
- </para>
- </listitem>
- <listitem>
- <para>
- Select the image you want put on the TeleMetrum, which should have a
- name in the form telemetrum-v1.2-1.0.0.ihx. It should be visible
- in the default directory, if not you may have to poke around
- your system to find it.
- </para>
- </listitem>
- <listitem>
- <para>
- Make sure the configuration parameters are reasonable
- looking. If the serial number and/or RF configuration
- values aren't right, you'll need to change them.
- </para>
- </listitem>
- <listitem>
- <para>
- Hit the 'OK' button and the software should proceed to flash
- the TeleMetrum with new firmware, showing a progress bar.
- </para>
- </listitem>
- <listitem>
- <para>
- Confirm that the TeleMetrum board seems to have updated OK, which you
- can do by plugging in to it over USB and using a terminal program
- to connect to the board and issue the 'v' command to check
- the version, etc.
- </para>
- </listitem>
- <listitem>
- <para>
- If something goes wrong, give it another try.
- </para>
- </listitem>
- </orderedlist>
- </section>
- <section>
- <title>Updating TeleMini Firmware</title>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
-<para>
- You'll need a special 'programming cable' to reprogram the
- TeleMini. You can make your own using an 8-pin MicroMaTch
- connector on one end and a set of four pins on the other.
- </para>
-</listitem>
- <listitem>
-<para>
- Take the 2 screws out of the TeleDongle v0.2 or TeleBT v1.0 case to get access
- to the circuit board.
- </para>
-</listitem>
- <listitem>
-<para>
- Plug the 8-pin end of the programming cable to the matching
- connector on the TeleDongle v0.2 or TeleBT v1.0, and the 4-pins into the holes
- in the TeleMini circuit board. Note that the MicroMaTch
- connector has an alignment pin that goes through a hole in
- the PC board when you have the cable oriented correctly, and
- that pin 1 on the TeleMini board is marked with a square pad
- while the other pins have round pads.
- </para>
-</listitem>
- <listitem>
-<para>
- Attach a battery to the TeleMini board.
- </para>
-</listitem>
- <listitem>
-<para>
- Plug the TeleDongle v0.2 or TeleBT v1.0 into your computer's USB port, and power
- up the TeleMini
- </para>
-</listitem>
- <listitem>
-<para>
- Run AltosUI, and select 'Flash Image' from the File menu.
- </para>
-</listitem>
- <listitem>
-<para>
- Pick the TeleDongle v0.2 or TeleBT v1.0 device from the list, identifying it as the
- programming device.
- </para>
-</listitem>
- <listitem>
-<para>
- Select the image you want put on the TeleMini, which should have a
- name in the form telemini-v1.0-1.0.0.ihx. It should be visible
- in the default directory, if not you may have to poke around
- your system to find it.
- </para>
-</listitem>
- <listitem>
-<para>
- Make sure the configuration parameters are reasonable
- looking. If the serial number and/or RF configuration
- values aren't right, you'll need to change them.
- </para>
-</listitem>
- <listitem>
-<para>
- Hit the 'OK' button and the software should proceed to flash
- the TeleMini with new firmware, showing a progress bar.
- </para>
-</listitem>
- <listitem>
-<para>
- Confirm that the TeleMini board seems to have updated OK, which you
- can do by configuring it over the radio link through the TeleDongle, or
- letting it come up in “flight” mode and listening for telemetry.
- </para>
-</listitem>
- <listitem>
-<para>
- If something goes wrong, give it another try.
- </para>
-</listitem>
- </orderedlist>
- </section>
- <section>
- <title>Updating TeleDongle v0.2 Firmware</title>
- <para>
- Updating TeleDongle v0.2 firmware is just like updating
- TeleMetrum v1.x or TeleMini
- firmware, but you use either a TeleMetrum v1.x, TeleDongle
- v0.2 or TeleBT v1.0 as the programmer.
- </para>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
-<para>
- Find the 'programming cable' that you got as part of the starter
- kit, that has a red 8-pin MicroMaTch connector on one end and a
- red 4-pin MicroMaTch connector on the other end.
- </para>
-</listitem>
- <listitem>
-<para>
- Find the USB cable that you got as part of the starter kit, and
- plug the “mini” end in to the mating connector on TeleMetrum
- v1.x, TeleDongle v0.2 or TeleBT v1.0.
- </para>
-</listitem>
- <listitem>
-<para>
- Take the 2 screws out of the TeleDongle v0.2 or TeleBT v1.0 case to get access
- to the circuit board.
- </para>
-</listitem>
- <listitem>
-<para>
- Plug the 8-pin end of the programming cable to the
- matching connector on the programmer, and the 4-pin end to the
- matching connector on the TeleDongle v0.2.
- Note that each MicroMaTch connector has an alignment pin that
- goes through a hole in the PC board when you have the cable
- oriented correctly.
- </para>
-</listitem>
- <listitem>
-<para>
- Attach a battery to the TeleMetrum v1.x board if you're using one.
- </para>
-</listitem>
- <listitem>
-<para>
- Plug both the programmer and the TeleDongle into your computer's USB
- ports, and power up the programmer.
- </para>
-</listitem>
- <listitem>
-<para>
- Run AltosUI, and select 'Flash Image' from the File menu.
- </para>
-</listitem>
- <listitem>
-<para>
- Pick the programmer device from the list, identifying it as the
- programming device.
- </para>
-</listitem>
- <listitem>
-<para>
- Select the image you want put on the TeleDongle v0.2, which should have a
- name in the form teledongle-v0.2-1.0.0.ihx. It should be visible
- in the default directory, if not you may have to poke around
- your system to find it.
- </para>
-</listitem>
- <listitem>
-<para>
- Make sure the configuration parameters are reasonable
- looking. If the serial number and/or RF configuration
- values aren't right, you'll need to change them. The
- TeleDongle v0.2
- serial number is on the “bottom” of the circuit board, and can
- usually be read through the translucent blue plastic case without
- needing to remove the board from the case.
- </para>
-</listitem>
- <listitem>
-<para>
- Hit the 'OK' button and the software should proceed to flash
- the TeleDongle v0.2 with new firmware, showing a progress bar.
- </para>
-</listitem>
- <listitem>
-<para>
- Confirm that the TeleDongle v0.2 board seems to have updated OK, which you
- can do by plugging in to it over USB and using a terminal program
- to connect to the board and issue the 'v' command to check
- the version, etc. Once you're happy, remove the programming cable
- and put the cover back on the TeleDongle v0.2.
- </para>
-</listitem>
- <listitem>
-<para>
- If something goes wrong, give it another try.
- </para>
-</listitem>
- </orderedlist>
- <para>
- Be careful removing the programming cable from the locking 8-pin
- connector on TeleMetrum. You'll need a fingernail or perhaps a thin
- screwdriver or knife blade to gently pry the locking ears out
- slightly to extract the connector. We used a locking connector on
- TeleMetrum to help ensure that the cabling to companion boards
- used in a rocket don't ever come loose accidentally in flight.
- </para>
- </section>
- </chapter>
- <chapter>
- <title>Hardware Specifications</title>
- <section>
- <title>
- TeleMega Specifications
- </title>
- <itemizedlist>
- <listitem>
- <para>
- Recording altimeter for model rocketry.
- </para>
- </listitem>
- <listitem>
- <para>
- Supports dual deployment and four auxiliary pyro channels
- (a total of 6 events).
- </para>
- </listitem>
- <listitem>
- <para>
- 70cm 40mW ham-band transceiver for telemetry down-link.
- </para>
- </listitem>
- <listitem>
- <para>
- Barometric pressure sensor good to 100k feet MSL.
- </para>
- </listitem>
- <listitem>
- <para>
- 1-axis high-g accelerometer for motor characterization, capable of
- +/- 102g.
- </para>
- </listitem>
- <listitem>
- <para>
- 9-axis IMU including integrated 3-axis accelerometer,
- 3-axis gyroscope and 3-axis magnetometer.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board, integrated uBlox Max 7 GPS receiver with 5Hz update rate capability.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board 8 Megabyte non-volatile memory for flight data storage.
- </para>
- </listitem>
- <listitem>
- <para>
- USB interface for battery charging, configuration, and data recovery.
- </para>
- </listitem>
- <listitem>
- <para>
- Fully integrated support for Li-Po rechargeable batteries.
- </para>
- </listitem>
- <listitem>
- <para>
- Can use either main system Li-Po or optional separate pyro battery
- to fire e-matches.
- </para>
- </listitem>
- <listitem>
- <para>
- 3.25 x 1.25 inch board designed to fit inside 38mm air-frame coupler tube.
- </para>
- </listitem>
- </itemizedlist>
- </section>
- <section>
- <title>
- EasyMega Specifications
- </title>
- <itemizedlist>
- <listitem>
- <para>
- Recording altimeter for model rocketry.
- </para>
- </listitem>
- <listitem>
- <para>
- Supports dual deployment and four auxiliary pyro channels
- (a total of 6 events).
- </para>
- </listitem>
- <listitem>
- <para>
- Barometric pressure sensor good to 100k feet MSL.
- </para>
- </listitem>
- <listitem>
- <para>
- 1-axis high-g accelerometer for motor characterization, capable of
- +/- 102g.
- </para>
- </listitem>
- <listitem>
- <para>
- 9-axis IMU including integrated 3-axis accelerometer,
- 3-axis gyroscope and 3-axis magnetometer.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board 8 Megabyte non-volatile memory for flight data storage.
- </para>
- </listitem>
- <listitem>
- <para>
- USB interface for battery charging, configuration, and data recovery.
- </para>
- </listitem>
- <listitem>
- <para>
- Fully integrated support for Li-Po rechargeable batteries.
- </para>
- </listitem>
- <listitem>
- <para>
- Can use either main system Li-Po or optional separate pyro battery
- to fire e-matches.
- </para>
- </listitem>
- <listitem>
- <para>
- 1.25 x 1.25 inch board designed to fit inside 38mm air-frame coupler tube.
- </para>
- </listitem>
- </itemizedlist>
- </section>
- <section>
- <title>
- TeleMetrum v2 Specifications
- </title>
- <itemizedlist>
- <listitem>
- <para>
- Recording altimeter for model rocketry.
- </para>
- </listitem>
- <listitem>
- <para>
- Supports dual deployment (can fire 2 ejection charges).
- </para>
- </listitem>
- <listitem>
- <para>
- 70cm, 40mW ham-band transceiver for telemetry down-link.
- </para>
- </listitem>
- <listitem>
- <para>
- Barometric pressure sensor good to 100k feet MSL.
- </para>
- </listitem>
- <listitem>
- <para>
- 1-axis high-g accelerometer for motor characterization, capable of
- +/- 102g.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board, integrated uBlox Max 7 GPS receiver with 5Hz update rate capability.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board 8 Megabyte non-volatile memory for flight data storage.
- </para>
- </listitem>
- <listitem>
- <para>
- USB interface for battery charging, configuration, and data recovery.
- </para>
- </listitem>
- <listitem>
- <para>
- Fully integrated support for Li-Po rechargeable batteries.
- </para>
- </listitem>
- <listitem>
- <para>
- Uses Li-Po to fire e-matches, can be modified to support
- optional separate pyro battery if needed.
- </para>
- </listitem>
- <listitem>
- <para>
- 2.75 x 1 inch board designed to fit inside 29mm air-frame coupler tube.
- </para>
- </listitem>
- </itemizedlist>
- </section>
- <section>
- <title>TeleMetrum v1 Specifications</title>
- <itemizedlist>
- <listitem>
- <para>
- Recording altimeter for model rocketry.
- </para>
- </listitem>
- <listitem>
- <para>
- Supports dual deployment (can fire 2 ejection charges).
- </para>
- </listitem>
- <listitem>
- <para>
- 70cm, 10mW ham-band transceiver for telemetry down-link.
- </para>
- </listitem>
- <listitem>
- <para>
- Barometric pressure sensor good to 45k feet MSL.
- </para>
- </listitem>
- <listitem>
- <para>
- 1-axis high-g accelerometer for motor characterization, capable of
- +/- 50g using default part.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board, integrated GPS receiver with 5Hz update rate capability.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board 1 megabyte non-volatile memory for flight data storage.
- </para>
- </listitem>
- <listitem>
- <para>
- USB interface for battery charging, configuration, and data recovery.
- </para>
- </listitem>
- <listitem>
- <para>
- Fully integrated support for Li-Po rechargeable batteries.
- </para>
- </listitem>
- <listitem>
- <para>
- Uses Li-Po to fire e-matches, can be modified to support
- optional separate pyro battery if needed.
- </para>
- </listitem>
- <listitem>
- <para>
- 2.75 x 1 inch board designed to fit inside 29mm air-frame coupler tube.
- </para>
- </listitem>
- </itemizedlist>
- </section>
- <section>
- <title>
- TeleMini v2.0 Specifications
- </title>
- <itemizedlist>
- <listitem>
- <para>
- Recording altimeter for model rocketry.
- </para>
- </listitem>
- <listitem>
- <para>
- Supports dual deployment (can fire 2 ejection charges).
- </para>
- </listitem>
- <listitem>
- <para>
- 70cm, 10mW ham-band transceiver for telemetry down-link.
- </para>
- </listitem>
- <listitem>
- <para>
- Barometric pressure sensor good to 100k feet MSL.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board 1 megabyte non-volatile memory for flight data storage.
- </para>
- </listitem>
- <listitem>
- <para>
- USB interface for configuration, and data recovery.
- </para>
- </listitem>
- <listitem>
- <para>
- Support for Li-Po rechargeable batteries (using an
- external charger), or any 3.7-15V external battery.
- </para>
- </listitem>
- <listitem>
- <para>
- Uses Li-Po to fire e-matches, can be modified to support
- optional separate pyro battery if needed.
- </para>
- </listitem>
- <listitem>
- <para>
- 1.5 x .8 inch board designed to fit inside 24mm air-frame coupler tube.
- </para>
- </listitem>
- </itemizedlist>
- </section>
- <section>
- <title>
- TeleMini v1.0 Specifications
- </title>
- <itemizedlist>
- <listitem>
- <para>
- Recording altimeter for model rocketry.
- </para>
- </listitem>
- <listitem>
- <para>
- Supports dual deployment (can fire 2 ejection charges).
- </para>
- </listitem>
- <listitem>
- <para>
- 70cm, 10mW ham-band transceiver for telemetry down-link.
- </para>
- </listitem>
- <listitem>
- <para>
- Barometric pressure sensor good to 45k feet MSL.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board 5 kilobyte non-volatile memory for flight data storage.
- </para>
- </listitem>
- <listitem>
- <para>
- RF interface for configuration, and data recovery.
- </para>
- </listitem>
- <listitem>
- <para>
- Support for Li-Po rechargeable batteries, using an external charger.
- </para>
- </listitem>
- <listitem>
- <para>
- Uses Li-Po to fire e-matches, can be modified to support
- optional separate pyro battery if needed.
- </para>
- </listitem>
- <listitem>
- <para>
- 1.5 x .5 inch board designed to fit inside 18mm air-frame coupler tube.
- </para>
- </listitem>
- </itemizedlist>
- </section>
- <section>
- <title>
- EasyMini Specifications
- </title>
- <itemizedlist>
- <listitem>
- <para>
- Recording altimeter for model rocketry.
- </para>
- </listitem>
- <listitem>
- <para>
- Supports dual deployment (can fire 2 ejection charges).
- </para>
- </listitem>
- <listitem>
- <para>
- Barometric pressure sensor good to 100k feet MSL.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board 1 megabyte non-volatile memory for flight data storage.
- </para>
- </listitem>
- <listitem>
- <para>
- USB interface for configuration, and data recovery.
- </para>
- </listitem>
- <listitem>
- <para>
- Support for Li-Po rechargeable batteries (using an
- external charger), or any 3.7-15V external battery.
- </para>
- </listitem>
- <listitem>
- <para>
- Uses Li-Po to fire e-matches, can be modified to support
- optional separate pyro battery if needed.
- </para>
- </listitem>
- <listitem>
- <para>
- 1.5 x .8 inch board designed to fit inside 24mm air-frame coupler tube.
- </para>
- </listitem>
- </itemizedlist>
- </section>
- </chapter>
- <chapter>
- <title>FAQ</title>
- <para>
- <emphasis>TeleMetrum seems to shut off when disconnected from the
- computer.</emphasis> <?linebreak?>
- Make sure the battery is adequately charged. Remember the
- unit will pull more power than the USB port can deliver before the
- GPS enters “locked” mode. The battery charges best when TeleMetrum
- is turned off.
- </para>
- <para>
- <emphasis>It's impossible to stop the TeleDongle when it's in “p” mode, I have
- to unplug the USB cable? </emphasis><?linebreak?>
- Make sure you have tried to “escape out” of
- this mode. If this doesn't work the reboot procedure for the
- TeleDongle *is* to simply unplug it. 'cu' however will retain it's
- outgoing buffer IF your “escape out” ('~~') does not work.
- At this point using either 'ao-view' (or possibly
- 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
- communication.
- </para>
- <para>
- <emphasis>The amber LED (on the TeleMetrum) lights up when both
- battery and USB are connected. Does this mean it's charging?
- </emphasis><?linebreak?>
- Yes, the yellow LED indicates the charging at the 'regular' rate.
- If the led is out but the unit is still plugged into a USB port,
- then the battery is being charged at a 'trickle' rate.
- </para>
- <para>
- <emphasis>There are no “dit-dah-dah-dit” sound or lights like the manual
- mentions?</emphasis><?linebreak?>
- That's the “pad” mode. Weak batteries might be the problem.
- It is also possible that the flight computer is horizontal and the
- output
- is instead a “dit-dit” meaning 'idle'. For TeleMini, it's possible that
- it received a command packet which would have left it in “pad” mode.
- </para>
- <para>
- <emphasis>How do I save flight data?</emphasis><?linebreak?>
- Live telemetry is written to file(s) whenever AltosUI is connected
- to the TeleDongle. The file area defaults to ~/TeleMetrum
- but is easily changed using the menus in AltosUI. The files that
- are written end in '.telem'. The after-flight
- data-dumped files will end in .eeprom and represent continuous data
- unlike the .telem files that are subject to losses
- along the RF data path.
- See the above instructions on what and how to save the eeprom stored
- data after physically retrieving your altimeter. Make sure to save
- the on-board data after each flight; while the TeleMetrum can store
- multiple flights, you never know when you'll lose the altimeter...
- </para>
- </chapter>
- <appendix>
- <title>Notes for Older Software</title>
- <para>
- <emphasis>
- Before AltosUI was written, using Altus Metrum devices required
- some finesse with the Linux command line. There was a limited
- GUI tool, ao-view, which provided functionality similar to the
- Monitor Flight window in AltosUI, but everything else was a
- fairly 80's experience. This appendix includes documentation for
- using that software.
- </emphasis>
- </para>
- <para>
- Both TeleMetrum and TeleDongle can be directly communicated
- with using USB ports. The first thing you should try after getting
- both units plugged into to your computer's USB port(s) is to run
- 'ao-list' from a terminal-window to see what port-device-name each
- device has been assigned by the operating system.
- You will need this information to access the devices via their
- respective on-board firmware and data using other command line
- programs in the AltOS software suite.
- </para>
- <para>
- TeleMini can be communicated with through a TeleDongle device
- over the radio link. When first booted, TeleMini listens for a
- TeleDongle device and if it receives a packet, it goes into
- 'idle' mode. Otherwise, it goes into 'pad' mode and waits to be
- launched. The easiest way to get it talking is to start the
- communication link on the TeleDongle and the power up the
- TeleMini board.
- </para>
- <para>
- To access the device's firmware for configuration you need a terminal
- program such as you would use to talk to a modem. The software
- authors prefer using the program 'cu' which comes from the UUCP package
- on most Unix-like systems such as Linux. An example command line for
- cu might be 'cu -l /dev/ttyACM0', substituting the correct number
- indicated from running the
- ao-list program. Another reasonable terminal program for Linux is
- 'cutecom'. The default 'escape'
- character used by CU (i.e. the character you use to
- issue commands to cu itself instead of sending the command as input
- to the connected device) is a '~'. You will need this for use in
- only two different ways during normal operations. First is to exit
- the program by sending a '~.' which is called a 'escape-disconnect'
- and allows you to close-out from 'cu'. The
- second use will be outlined later.
- </para>
- <para>
- All of the Altus Metrum devices share the concept of a two level
- command set in their firmware.
- The first layer has several single letter commands. Once
- you are using 'cu' (or 'cutecom') sending (typing) a '?'
- returns a full list of these
- commands. The second level are configuration sub-commands accessed
- using the 'c' command, for
- instance typing 'c?' will give you this second level of commands
- (all of which require the
- letter 'c' to access). Please note that most configuration options
- are stored only in Flash memory; TeleDongle doesn't provide any storage
- for these options and so they'll all be lost when you unplug it.
- </para>
- <para>
- Try setting these configuration ('c' or second level menu) values. A good
- place to start is by setting your call sign. By default, the boards
- use 'N0CALL' which is cute, but not exactly legal!
- Spend a few minutes getting comfortable with the units, their
- firmware, and 'cu' (or possibly 'cutecom').
- For instance, try to send
- (type) a 'c r 2' and verify the channel change by sending a 'c s'.
- Verify you can connect and disconnect from the units while in your
- terminal program by sending the escape-disconnect mentioned above.
- </para>
- <para>
- To set the radio frequency, use the 'c R' command to specify the
- radio transceiver configuration parameter. This parameter is computed
- using the desired frequency, 'F', the radio calibration parameter, 'C' (showed by the 'c s' command) and
- the standard calibration reference frequency, 'S', (normally 434.550MHz):
- <programlisting>
- R = F / S * C
- </programlisting>
- Round the result to the nearest integer value.
- As with all 'c' sub-commands, follow this with a 'c w' to write the
- change to the parameter block in the on-board flash on
- your altimeter board if you want the change to stay in place across reboots.
- </para>
- <para>
- To set the apogee delay, use the 'c d' command.
- As with all 'c' sub-commands, follow this with a 'c w' to write the
- change to the parameter block in the on-board DataFlash chip.
- </para>
- <para>
- To set the main deployment altitude, use the 'c m' command.
- As with all 'c' sub-commands, follow this with a 'c w' to write the
- change to the parameter block in the on-board DataFlash chip.
- </para>
- <para>
- To calibrate the radio frequency, connect the UHF antenna port to a
- frequency counter, set the board to 434.550MHz, and use the 'C'
- command to generate a CW carrier. Wait for the transmitter temperature
- to stabilize and the frequency to settle down.
- Then, divide 434.550 MHz by the
- measured frequency and multiply by the current radio cal value show
- in the 'c s' command. For an unprogrammed board, the default value
- is 1186611 for cc1111 based products and 7119667 for cc1120
- based products. Take the resulting integer and program it using the 'c f'
- command. Testing with the 'C' command again should show a carrier
- within a few tens of Hertz of the intended frequency.
- As with all 'c' sub-commands, follow this with a 'c w' to write the
- change to the configuration memory.
- </para>
- <para>
- Note that the 'reboot' command, which is very useful on the altimeters,
- will likely just cause problems with the dongle. The *correct* way
- to reset the dongle is just to unplug and re-plug it.
- </para>
- <para>
- A fun thing to do at the launch site and something you can do while
- learning how to use these units is to play with the radio link access
- between an altimeter and the TeleDongle. Be aware that you *must* create
- some physical separation between the devices, otherwise the link will
- not function due to signal overload in the receivers in each device.
- </para>
- <para>
- Now might be a good time to take a break and read the rest of this
- manual, particularly about the two “modes” that the altimeters
- can be placed in. TeleMetrum uses the position of the device when booting
- up will determine whether the unit is in “pad” or “idle” mode. TeleMini
- enters “idle” mode when it receives a command packet within the first 5 seconds
- of being powered up, otherwise it enters “pad” mode.
- </para>
- <para>
- You can access an altimeter in idle mode from the TeleDongle's USB
- connection using the radio link
- by issuing a 'p' command to the TeleDongle. Practice connecting and
- disconnecting ('~~' while using 'cu') from the altimeter. If
- you cannot escape out of the “p” command, (by using a '~~' when in
- CU) then it is likely that your kernel has issues. Try a newer version.
- </para>
- <para>
- Using this radio link allows you to configure the altimeter, test
- fire e-matches and igniters from the flight line, check pyro-match
- continuity and so forth. You can leave the unit turned on while it
- is in 'idle mode' and then place the
- rocket vertically on the launch pad, walk away and then issue a
- reboot command. The altimeter will reboot and start sending data
- having changed to the “pad” mode. If the TeleDongle is not receiving
- this data, you can disconnect 'cu' from the TeleDongle using the
- procedures mentioned above and THEN connect to the TeleDongle from
- inside 'ao-view'. If this doesn't work, disconnect from the
- TeleDongle, unplug it, and try again after plugging it back in.
- </para>
- <para>
- In order to reduce the chance of accidental firing of pyrotechnic
- charges, the command to fire a charge is intentionally somewhat
- difficult to type, and the built-in help is slightly cryptic to
- prevent accidental echoing of characters from the help text back at
- the board from firing a charge. The command to fire the apogee
- drogue charge is 'i DoIt drogue' and the command to fire the main
- charge is 'i DoIt main'.
- </para>
- <para>
- On TeleMetrum, the GPS will eventually find enough satellites, lock in on them,
- and 'ao-view' will both auditorily announce and visually indicate
- that GPS is ready.
- Now you can launch knowing that you have a good data path and
- good satellite lock for flight data and recovery. Remember
- you MUST tell ao-view to connect to the TeleDongle explicitly in
- order for ao-view to be able to receive data.
- </para>
- <para>
- The altimeters provide RDF (radio direction finding) tones on
- the pad, during descent and after landing. These can be used to
- locate the rocket using a directional antenna; the signal
- strength providing an indication of the direction from receiver to rocket.
- </para>
- <para>
- TeleMetrum also provides GPS tracking data, which can further simplify
- locating the rocket once it has landed. (The last good GPS data
- received before touch-down will be on the data screen of 'ao-view'.)
- </para>
- <para>
- Once you have recovered the rocket you can download the eeprom
- contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over
- either a USB cable or over the radio link using TeleDongle.
- And by following the man page for 'ao-postflight' you can create
- various data output reports, graphs, and even KML data to see the
- flight trajectory in Google-earth. (Moving the viewing angle making
- sure to connect the yellow lines while in Google-earth is the proper
- technique.)
- </para>
- <para>
- As for ao-view.... some things are in the menu but don't do anything
- very useful. The developers have stopped working on ao-view to focus
- on a new, cross-platform ground station program. So ao-view may or
- may not be updated in the future. Mostly you just use
- the Log and Device menus. It has a wonderful display of the incoming
- flight data and I am sure you will enjoy what it has to say to you
- once you enable the voice output!
- </para>
- </appendix>
- <appendix>
- <title>Drill Templates</title>
- <para>
- These images, when printed, provide precise templates for the
- mounting holes in Altus Metrum flight computers
- </para>
- <section>
- <title>TeleMega template</title>
- <para>
- TeleMega has overall dimensions of 1.250 x 3.250 inches, and
- the mounting holes are sized for use with 4-40 or M3 screws.
- </para>
- <informalfigure>
- <mediaobject id="TeleMegaTemplate">
- <imageobject>
- <imagedata format="SVG" fileref="telemega.svg"
- scalefit="0" scale="100" align="center" />
- </imageobject>
- </mediaobject>
- </informalfigure>
- </section>
- <section>
- <title>EasyMega template</title>
- <para>
- EasyMega has overall dimensions of 1.250 x 2.250 inches, and
- the mounting holes are sized for use with 4-40 or M3 screws.
- </para>
- <informalfigure>
- <mediaobject id="EasyMegaTemplate">
- <imageobject>
- <imagedata format="SVG" fileref="easymega.svg"
- scalefit="0" scale="100" align="center" />
- </imageobject>
- </mediaobject>
- </informalfigure>
- </section>
- <section>
- <title>TeleMetrum template</title>
- <para>
- TeleMetrum has overall dimensions of 1.000 x 2.750 inches, and the
- mounting holes are sized for use with 4-40 or M3 screws.
- </para>
- <informalfigure>
- <mediaobject id="TeleMetrumTemplate">
- <imageobject>
- <imagedata format="SVG" fileref="telemetrum.svg"
- scalefit="0" scale="100" align="center" />
- </imageobject>
- </mediaobject>
- </informalfigure>
- </section>
- <section>
- <title>TeleMini v2/EasyMini template</title>
- <para>
- TeleMini v2 and EasyMini have overall dimensions of 0.800 x 1.500 inches, and the
- mounting holes are sized for use with 4-40 or M3 screws.
- </para>
- <informalfigure>
- <mediaobject id="MiniTemplate">
- <imageobject>
- <imagedata format="SVG" fileref="easymini.svg"
- scalefit="0" scale="100" align="center" />
- </imageobject>
- </mediaobject>
- </informalfigure>
- </section>
- <section>
- <title>TeleMini v1 template</title>
- <para>
- TeleMini has overall dimensions of 0.500 x 1.500 inches, and the
- mounting holes are sized for use with 2-56 or M2 screws.
- </para>
- <informalfigure>
- <mediaobject id="TeleMiniTemplate">
- <imageobject>
- <imagedata format="SVG" fileref="telemini.svg"
- scalefit="0" scale="100" align="center" />
- </imageobject>
- </mediaobject>
- </informalfigure>
- </section>
- </appendix>
- <appendix>
- <title>Calibration</title>
- <para>
- There are only two calibrations required for TeleMetrum and
- TeleMega, and only one for EasyMega, TeleDongle, TeleMini and EasyMini.
- All boards are shipped from the factory pre-calibrated, but
- the procedures are documented here in case they are ever
- needed. Re-calibration is not supported by AltosUI, you must
- connect to the board with a serial terminal program and
- interact directly with the on-board command interpreter to
- effect calibration.
- </para>
- <section>
- <title>Radio Frequency</title>
- <para>
- The radio frequency is synthesized from a clock based on the
- crystal on the board. The actual frequency of this oscillator
- must be measured to generate a calibration constant. While our
- GFSK modulation
- bandwidth is wide enough to allow boards to communicate even when
- their oscillators are not on exactly the same frequency, performance
- is best when they are closely matched.
- Radio frequency calibration requires a calibrated frequency counter.
- Fortunately, once set, the variation in frequency due to aging and
- temperature changes is small enough that re-calibration by customers
- should generally not be required.
- </para>
- <para>
- To calibrate the radio frequency, connect the UHF antenna
- port to a frequency counter, set the board to 434.550MHz,
- and use the 'C' command in the on-board command interpreter
- to generate a CW carrier. For USB-enabled boards, this is
- best done over USB. For TeleMini v1, note that the only way
- to escape the 'C' command is via power cycle since the board
- will no longer be listening for commands once it starts
- generating a CW carrier.
- </para>
- <para>
- Wait for the transmitter temperature to stabilize and the frequency
- to settle down. Then, divide 434.550 MHz by the
- measured frequency and multiply by the current radio cal value show
- in the 'c s' command. For an unprogrammed board, the default value
- is 1186611. Take the resulting integer and program it using the 'c f'
- command. Testing with the 'C' command again should show a carrier
- within a few tens of Hertz of the intended frequency.
- As with all 'c' sub-commands, follow this with a 'c w' to write the
- change to the parameter block in the on-board storage chip.
- </para>
- <para>
- Note that any time you re-do the radio frequency calibration, the
- radio frequency is reset to the default 434.550 Mhz. If you want
- to use another frequency, you will have to set that again after
- calibration is completed.
- </para>
- </section>
- <section>
- <title>TeleMetrum, TeleMega and EasyMega Accelerometers</title>
- <para>
- While barometric sensors are factory-calibrated,
- accelerometers are not, and so each must be calibrated once
- installed in a flight computer. Explicitly calibrating the
- accelerometers also allows us to load any compatible device.
- We perform a two-point calibration using gravity.
- </para>
- <para>
- To calibrate the acceleration sensor, use the 'c a 0' command. You
- will be prompted to orient the board vertically with the UHF antenna
- up and press a key, then to orient the board vertically with the
- UHF antenna down and press a key. Note that the accuracy of this
- calibration depends primarily on how perfectly vertical and still
- the board is held during the cal process. As with all 'c'
- sub-commands, follow this with a 'c w' to write the
- change to the parameter block in the on-board DataFlash chip.
- </para>
- <para>
- The +1g and -1g calibration points are included in each telemetry
- frame and are part of the header stored in onboard flash to be
- downloaded after flight. We always store and return raw ADC
- samples for each sensor... so nothing is permanently “lost” or
- “damaged” if the calibration is poor.
- </para>
- <para>
- In the unlikely event an accel cal goes badly, it is possible
- that TeleMetrum, TeleMega or EasyMega may always come up in 'pad mode'
- and as such not be listening to either the USB or radio link.
- If that happens, there is a special hook in the firmware to
- force the board back in to 'idle mode' so you can re-do the
- cal. To use this hook, you just need to ground the SPI clock
- pin at power-on. This pin is available as pin 2 on the 8-pin
- companion connector, and pin 1 is ground. So either
- carefully install a fine-gauge wire jumper between the two
- pins closest to the index hole end of the 8-pin connector, or
- plug in the programming cable to the 8-pin connector and use
- a small screwdriver or similar to short the two pins closest
- to the index post on the 4-pin end of the programming cable,
- and power up the board. It should come up in 'idle mode'
- (two beeps), allowing a re-cal.
- </para>
- </section>
- </appendix>
- <appendix>
- <title>Igniter Current</title>
- <para>
- The question "how much igniter current can Altus Metrum products
- handle?" comes up fairly frequently. The short answer is "more than
- you're likely to need", the remainder of this appendix provides a
- longer answer.
- </para>
- <section>
- <title>Current Products</title>
- <para>
- The FET switches we're using on all of our current products that
- have pyro channels are the Vishay Siliconix Si7232DN. These parts
- have exceptionally low Rds(on) values, better than 0.02 ohms! That
- means they aren't making a lot of heat... and the limit on current
- is "package limited", meaning it's all about how much you can heat
- the die before something breaks.
- </para>
- <para>
- Cutting to the chase, the Si7232DN specs are 25 amps <emphasis>continuous</emphasis> at
- 20V at a temperature of 25C. In pulsed mode, they're rated for 40A.
- However, those specs are a little mis-leading because it really is
- all about the heat generated... you can get something like 85A
- through one briefly. Note that a typical commercial e-match only
- needed about 13 microseconds to fire in tests on my bench a couple
- years ago!
- </para>
- <para>
- So a great plan is to use something like an e-match as the initiator
- and build up pyrogen(s) as required to actually light what you're
- trying to light... But if you want to use a high-current igniter,
- we can probably handle it!
- </para>
- </section>
- <section>
- <title>Version 1 Products</title>
- <para>
- The FET switches used on TeleMetrum v1 and TeleMini v1 products
- were Fairchild FDS9926A. The Rds(on) values under our operating
- conditions are on the order of 0.04 ohms. These parts were rated
- for a continuous current-carrying capacity of 6.5A, and a pulsed
- current capacity of 20A.
- </para>
- <para>
- As with the more modern parts, the real limit is based on the heat
- generated in the part during the firing interval. So, while the
- specs on these parts aren't as good as the ones we use on current
- products, they were still great, and we never had a complaint about
- current carrying capacity with any of our v1 boards.
- </para>
- </section>
- </appendix>
- <appendix>
- <title>Release Notes</title>
- <simplesect>
- <title>Version 1.6.1</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.6.1.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.6</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.6.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.5</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.5.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.4.1</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.4.1.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.4</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.4.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.3.2</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.3.2.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.3.1</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.3.1.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.3</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.3.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.2.1</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.2.1.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.2</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.2.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.1.1</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.1.1.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.1</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.1.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 1.0.1</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-1.0.1.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 0.9.2</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-0.9.2.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 0.9</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-0.9.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 0.8</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-0.8.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- <simplesect>
- <title>Version 0.7.1</title>
- <xi:include
- xmlns:xi="http://www.w3.org/2001/XInclude"
- href="release-notes-0.7.1.xsl"
- xpointer="xpointer(/article/*)"/>
- </simplesect>
- </appendix>
-</book>
-
-<!-- LocalWords: Altusmetrum
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