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-<?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 TeleMetrum, TeleMini and TeleDongle Devices</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>2013</year>
- <holder>Bdale Garbee and Keith Packard</holder>
- </copyright>
- <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>1.2</revnumber>
- <date>14 April 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 a few minor bugs in AltosUI and the AltOS firmware.
- </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>
- <acknowledgements>
- <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>
- </acknowledgements>
- <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.
- </para>
- <para>
- Our second device was TeleMini, a dual deploy altimeter with
- radio telemetry and radio direction finding. This device is only
- 13mm by 38mm (½ inch by 1½ inches) and can fit easily in an 18mm
- air-frame.
- </para>
- <para>
- Complementing TeleMetrum and TeleMini is TeleDongle, a USB to RF
- interface 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.
- </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>
- The TeleMetrum battery can be charged by plugging it into the
- corresponding socket of the TeleMetrum and then using the USB A to
- mini B
- cable to plug the TeleMetrum into your computer's USB socket. The
- TeleMetrum circuitry will charge the battery whenever it is plugged
- in, because the TeleMetrum's on-off switch does NOT control the
- charging circuitry.
- </para>
- <para>
- When the GPS chip is initially searching for
- satellites, TeleMetrum will consume more current than it can pull
- 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>
- The TeleMini battery can be charged by disconnecting it from the
- TeleMini 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>
- 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 Linux and are having problems, try moving
- to a fresher kernel (2.6.33 or newer), as the USB serial driver had
- ugly bugs in some earlier versions.
- </para>
- <para>
- Next you should obtain and install the AltOS software. These include
- the AltosUI ground station program, current firmware images for
- TeleMetrum, TeleMini and TeleDongle, 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>
- </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 both TeleMetrum and TeleMini are
- sensitive to sunlight. In normal TeleMetrum mounting situations, it
- 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, though, when
- designing an installation, for example, in an air-frame with a
- see-through plastic payload bay. It is particularly important to
- consider this with TeleMini, 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>Hardware Overview</title>
- <para>
- TeleMetrum is a 1 inch by 2.75 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 1/4
- 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>
- <para>
- TeleMini is a 0.5 inch by 1.5 inch circuit board. 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 1/4
- wave UHF wire antenna attached to the center of one end of
- the board is about 7 inches long, and wiring for a power switch and
- 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>
- <para>
- A typical TeleMetrum or TeleMini installation involves attaching
- only a suitable Lithium Polymer 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.
- </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 Li-Po 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>
- TeleMetrum also uses the screw terminal block for the power
- switch leads. On TeleMini, 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
- order an altimeter with an SMA connector for the UHF antenna
- connection, and, on TeleMetrum, you can unplug the integrated GPS
- antenna and select an appropriate off-board GPS antenna with
- cable terminating in a U.FL connector.
- </para>
- </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, 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
- TeleMetrum 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 doesn't have an accelerometer we can
- use to determine orientation, "idle" mode is selected when the
- board receives a command packet within the first five seconds
- of operation; if no packet is received, the board enters
- "flight" mode.
- </para>
- <para>
- At power on, you will hear three beeps or see three flashes
- ("S" in Morse code for start up) and then a pause while
- the altimeter completes initialization and self test, and decides
- which mode to enter next.
- </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 or
- rapidly alternating lights 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 to a TeleMetrum in idle mode
- over either
- USB or the radio link equivalently. TeleMini 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>
- One "neat trick" of particular value when TeleMetrum is 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 is configured 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
- offers an 'emergency recovery' mode. In this mode, TeleMini is
- configured as follows:
- <itemizedlist>
- <listitem>
- Sets the radio frequency to 434.550MHz
- </listitem>
- <listitem>
- Sets the radio calibration back to the factory value.
- </listitem>
- <listitem>
- Sets the callsign to N0CALL
- </listitem>
- <listitem>
- Does not go to 'pad' mode after five seconds.
- </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 includes 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 TeleMetrum 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>
- TeleMetrum provides 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 TeleMetrum
- 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 TeleMetrum can
- either be done with TeleMetrum directly connected to the
- computer via the USB cable, or through the radio
- link. TeleMini 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 or main deploy heights
- to respond to changing launch conditions. You can also
- 'reboot' the altimeter. Use this to remotely enable the
- flight computer by turning TeleMetrum 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 assembly 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>
- TeleMetrum only enables radio commanding in 'idle' mode, so
- make sure you have TeleMetrum lying horizontally when you turn
- it on. Otherwise, TeleMetrum 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 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
- selected 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>
- The chip our boards are based on incorporates 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 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 the hardware forward error
- correction support in the cc1111 chip, this allows us to have a very
- robust 38.4 kilobit data link with only 10 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. 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>Configurable Parameters</title>
- <para>
- Configuring an Altus Metrum altimeter for flight is very
- simple. Even on our baro-only TeleMini board, 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.
- </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>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>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>
- TeleMetrum version 1.1 and 1.2 have 2MB of on-board flash storage,
- enough to hold over 40 minutes of data at full data rate
- (100 samples/second). TeleMetrum 1.0 has 1MB of on-board
- storage. As data are stored at a reduced rate during descent
- (10 samples/second), there's plenty of space to store many
- flights worth of data.
- </para>
- <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 TeleMetrum can store more
- flights.
- </para>
- <para>
- All of the configuration data is also stored in the flash
- memory, which consumes 64kB on TeleMetrum v1.1/v1.2 and 256B on
- TeleMetrum v1.0. This configuration space is not available
- for storing flight log data.
- </para>
- <para>
- To compute the amount of space needed for a single flight,
- you can multiply the expected ascent time (in seconds) by
- 800, multiply the expected descent time (in seconds) by 80
- and add the two together. That will slightly under-estimate
- the storage (in bytes) needed for the flight. For instance,
- a flight spending 20 seconds in ascent and 150 seconds in
- descent will take about (20 * 800) + (150 * 80) = 28000
- bytes of storage. You could store dozens of these flights in
- the on-board flash.
- </para>
- <para>
- The default size, 192kB, allows for 10 flights of storage on
- TeleMetrum v1.1/v1.2 and 5 flights on TeleMetrum v1.0. This
- ensures that you won't need to erase the memory before
- flying each time while still allowing more than sufficient
- storage for each flight.
- </para>
- <para>
- As TeleMini does not contain an accelerometer, it stores
- data at 10 samples per second during ascent and one sample
- per second during descent. Each sample is a two byte reading
- from the barometer. These are stored in 5kB of
- on-chip flash memory which can hold 256 seconds at the
- ascent rate or 2560 seconds at the descent rate. Because of
- the limited storage, TeleMini cannot hold data for more than
- one flight, and so must be erased after each flight or it
- will not capture data for subsequent flights.
- </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 that has two
- TeleMetrum computers, 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 measures 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, TeleMetrum must be
- explicitly configured for either Antenna Up or Antenna
- Down. The default, Antenna Up, expects the end of the
- TeleMetrum 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>
-
- </chapter>
- <chapter>
-
- <title>AltosUI</title>
- <para>
- The AltosUI program provides a graphical user interface for
- interacting with the Altus Metrum product family, including
- TeleMetrum, TeleMini and TeleDongle. AltosUI can monitor telemetry data,
- configure TeleMetrum, TeleMini and TeleDongle devices and many other
- tasks. The primary interface window provides a selection of
- buttons, one for each major activity in the system. This manual
- is split into chapters, 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>
- <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. The
- radio inside TeleDongle operates down to about -99dBm;
- weaker signals may not be receivable. 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>
- <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:
- <itemizedlist>
- <listitem>
- <para>
- Battery Voltage. This indicates whether the Li-Po battery
- powering the TeleMetrum has sufficient charge to last for
- the duration of the flight. A value of more than
- 3.7V is required for a 'GO' status.
- </para>
- </listitem>
- <listitem>
- <para>
- Apogee Igniter Voltage. 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>
- <listitem>
- <para>
- Main Igniter Voltage. 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>
- <listitem>
- <para>
- On-board Data Logging. 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 can store multiple flights, depending
- on the configured maximum flight log size. 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>
- <listitem>
- <para>
- GPS Locked. For a TeleMetrum 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>
- <listitem>
- <para>
- GPS Ready. For a TeleMetrum 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>
- </itemizedlist>
- <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>
- </para>
- </section>
- <section>
- <title>Ascent</title>
- <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 and acceleration 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 TeleMetrum 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>
- <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>
- For TeleMetrum altimeters, 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>
- <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>
- Both TeleMini and TeleMetrum 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 will likely 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>Site Map</title>
- <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 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>
- 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>
- <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. As TeleMini has only a barometer, it
- records data at the same rate as the telemetry signal, but there will be
- no data lost due to telemetry drop-outs.
- </para>
- <para>
- Clicking on the 'Save Flight Data' button brings up a list of
- connected TeleMetrum and TeleDongle devices. If you select a
- TeleMetrum device, the flight data will be downloaded from that
- device directly. If you select a TeleDongle device, flight data
- will be downloaded from an altimeter 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>
- Once a flight record is selected, a window with two tabs is
- opened. The first tab contains a graph with acceleration
- (blue), velocity (green) and altitude (red) of the flight,
- measured in metric units. The
- apogee(yellow) and main(magenta) igniter voltages are also
- displayed; high voltages indicate continuity, low voltages
- indicate open circuits. The second tab contains some basic
- flight statistics.
- </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>
- <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>
- </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 (either .eeprom or .telem will do, remember that
- .eeprom files contain higher resolution and more continuous
- data). 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>
- <para>
- Select this button and then select either a TeleMetrum 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>
- <itemizedlist>
- <listitem>
- <para>
- Save. 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>
- <listitem>
- <para>
- Reset. This resets the dialog to the most recently saved values,
- erasing any changes you have made.
- </para>
- </listitem>
- <listitem>
- <para>
- Reboot. 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>
- <listitem>
- <para>
- Close. This closes the dialog. Any unsaved changes will be
- lost.
- </para>
- </listitem>
- </itemizedlist>
- <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>Radio Frequency</title>
- <para>
- This configures which of the configured frequencies to use for both
- telemetry and packet command mode. Note that if you set this
- value via packet command mode, you will have to reconfigure
- the TeleDongle frequency before you will be able to use packet
- command mode again.
- </para>
- </section>
- <section>
- <title>Radio 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>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>Ignite Mode</title>
- <para>
- TeleMetrum and TeleMini provide two igniter channels as they
- were originally designed as dual-deploy flight
- computers. This configuration parameter allows the two
- channels to be used in different configurations.
- </para>
- <itemizedlist>
- <listitem>
- <para>
- Dual Deploy. 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>
- <listitem>
- <para>
- Redundant Apogee. This fires both channels at
- apogee, the 'apogee' channel first followed after a two second
- delay by the 'main' channel.
- </para>
- </listitem>
- <listitem>
- <para>
- Redundant Main. 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>
- </itemizedlist>
- </section>
- <section>
- <title>Pad Orientation</title>
- <para>
- Because it includes an accelerometer, TeleMetrum is
- sensitive to the orientation of the board. By default, it
- expects 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>
- <itemizedlist>
- <listitem>
- <para>
- Antenna Up. In this mode, the antenna end of the
- TeleMetrum board must point forward, in line with the
- expected flight path.
- </para>
- </listitem>
- <listitem>
- <para>
- Antenna Down. In this mode, the antenna end of the
- TeleMetrum board must point aft, in line with the
- expected flight path.
- </para>
- </listitem>
- </itemizedlist>
- </section>
- </section>
- <section>
- <title>Configure AltosUI</title>
- <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>
- <itemizedlist>
- <listitem>
- <para>Enable—turns all voice announcements on and off</para>
- </listitem>
- <listitem>
- <para>
- Test Voice—Plays a short message allowing you to verify
- that the audio system is working and the volume settings
- are reasonable
- </para>
- </listitem>
- </itemizedlist>
- </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>
- </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, 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>
- <para>
- Select this button and then select a TeleDongle 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 the TeleDongle itself doesn't save any configuration
- data, the settings here are recorded on the local machine in
- the Java preferences database. Moving the TeleDongle 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>
- <itemizedlist>
- <listitem>
- <para>
- Save. 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>
- <listitem>
- <para>
- Reset. This resets the dialog to the most recently saved values,
- erasing any changes you have made.
- </para>
- </listitem>
- <listitem>
- <para>
- Close. This closes the dialog. Any unsaved changes will be
- lost.
- </para>
- </listitem>
- </itemizedlist>
- <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>Radio 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'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>
- <section>
- <title>Flash Image</title>
- <para>
- This reprograms any Altus Metrum device by using a TeleMetrum
- or TeleDongle as a programming dongle. Please read the
- directions for flashing devices in the Updating Device
- Firmware chapter below.
- </para>
- <para>
- Once you have the programmer and target devices connected,
- push the 'Flash Image' button. That will present a dialog box
- listing all of the connected devices. Carefully select the
- programmer device, not the device to be programmed.
- </para>
- <para>
- Next, select the image to flash to the device. These are named
- with the product name and firmware version. The file selector
- will start in the directory containing the firmware included
- with the AltosUI package. Navigate to the directory containing
- the desired firmware if it isn't there.
- </para>
- <para>
- Next, a small dialog containing the device serial number and
- RF calibration values should appear. If these values are
- incorrect (possibly due to a corrupted image in the device),
- enter the correct values here.
- </para>
- <para>
- Finally, a dialog containing a progress bar will follow the
- programming process.
- </para>
- <para>
- When programming is complete, the target device will
- reboot. Note that if the target device is connected via USB, you
- will have to unplug it and then plug it back in for the USB
- connection to reset so that you can communicate with the device
- again.
- </para>
- </section>
- <section>
- <title>Fire Igniter</title>
- <para>
- This activates the igniter circuits in TeleMetrum 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 TeleDongle or TeleMetrum
- device. This brings up another window which shows the current
- continuity test status for both apogee and main charges.
- </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>
- <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 three
- telemetry formats should be tried; by default, it only listens
- for the standard telemetry packets used in v1.0 and later
- firmware.
- </para>
- </section>
- <section>
- <title>Load Maps</title>
- <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. This loads a fairly large area
- around the launch site, which should cover any flight you're likely to make.
- </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 at run-time, so as new sites are sent in, they'll
- get automatically added to this list.
- </para>
- <para>
- If the launch site isn't in the list, you can manually enter the lat/lon values
- </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>
- <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.
- </para>
- </section>
- </chapter>
- <chapter>
- <title>AltosDroid</title>
- <para>
- AltosDroid provides the same flight monitoring capabilities as
- AltosUI, but runs on Android devices and is designed to connect
- to a TeleBT receiver over Bluetooth™. Altos Droid monitors
- telemetry data, logging it to internal storage in the Android
- device, and presents that data in a UI the same way the 'Monitor
- Flight' window does in AltosUI.
- </para>
- <para>
- This manual will explain how to configure AltosDroid, connect
- to TeleBT, operate the flight monitoring interface and describe
- what the displayed data means.
- </para>
- <section>
- <title>Installing AltosDroid</title>
- <para>
- AltosDroid is included in the Google Play store. To install
- it on your Android device, open 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>Connecting to TeleBT</title>
- </section>
- <section>
- <title>Configuring AltosDroid</title>
- </section>
- <section>
- <title>Flight Monitoring</title>
- </section>
- <section>
- <title>Downloading Flight Logs</title>
- </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 <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> or
- <ulink url="http://www.altusmetrum.org/TeleMini/">TeleMini</ulink> board 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 for hours.
- A 110mAh battery weighs less than a triple A battery and will run a TeleMetrum for
- a few hours, or a TeleMini for much (much) longer.
- </para>
- <para>
- By default, we ship the altimeters 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 choose to have an SMA connector
- installed so that you can run a coaxial cable to an antenna mounted
- elsewhere in the rocket.
- </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>
- 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 TeleMetrum-equipped 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.
- </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
- and Bdale both currently own and use the Yaesu VX-7R at launches.
- </para>
- <para>
- So, to recap, on the ground the hardware you'll need includes:
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- an antenna and feed-line or adapter
- </listitem>
- <listitem>
- a TeleDongle
- </listitem>
- <listitem>
- a notebook computer
- </listitem>
- <listitem>
- optionally, a hand-held GPS receiver
- </listitem>
- <listitem>
- optionally, an HT or receiver covering 435 MHz
- </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>
- In the future, we intend to offer "companion boards" for the rocket
- that will plug in to TeleMetrum to collect additional data, provide
- more pyro channels, and so forth.
- </para>
- <para>
- Also under design is a new flight computer with more sensors, more
- pyro channels, and a more powerful radio system designed for use
- in multi-stage, complex, and extreme altitude projects.
- </para>
- <para>
- We are also working on alternatives to TeleDongle. One is a
- a stand-alone, hand-held ground terminal that will allow monitoring
- the rocket's status, collecting data during flight, and logging data
- after flight without the need for a notebook computer on the
- flight line. Particularly since it is so difficult to read most
- notebook screens in direct sunlight, we think this will be a great
- thing to have. We are also working on a TeleDongle variant with
- Bluetooth that will work with Android phones and tablets.
- </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 oftentimes you find few perfect solutions. This chapter
- contains some suggestions about how to install Altus Metrum
- products into the 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 TeleMetrum, we use
- nylon standoffs and nylon screws; they're good to at least 50G
- and cannot cause any electrical issues on the board. For
- TeleMini, we usually cut small pieces of 1/16" 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>
- Make sure TeleMetrum is aligned precisely along the axis of
- acceleration so that the accelerometer can accurately
- capture data during the flight.
- </listitem>
- <listitem>
- 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.
- </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 is to 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 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 in TeleMetrum are highly
- sensitive and normally have no trouble tracking enough
- satellites to provide accurate position information for
- recovering the rocket. However, there are many ways to
- attenuate the GPS signal.
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- 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.
- </listitem>
- <listitem>
- 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.
- </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>
- Keep wires from different circuits apart. Moving circuits
- further apart will reduce RFI.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- Avoid resonant lengths. Know what frequencies are present
- in the environment and avoid having wire lengths near a
- natural resonant length. Altusmetrum products transmit on the
- 70cm amateur band, so you should avoid lengths that are a
- simple ratio of that length; essentially any multiple of 1/4
- of the wavelength (17.5cm).
- </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>
- The barometric sensor in the altimeter is 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>
- The big concept to understand is that you have to use a
- TeleDongle as a programmer to update a TeleMetrum or TeleMini,
- and a TeleMetrum or other TeleDongle to program the TeleDongle
- Due to limited memory resources in the cc1111, we don't support
- programming directly over USB.
- </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>
- We recommend updating the altimeter first, before updating TeleDongle.
- </para>
- <section>
- <title>Updating TeleMetrum Firmware</title>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- 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.
- </listitem>
- <listitem>
- Take the 2 screws out of the TeleDongle case to get access
- to the circuit board.
- </listitem>
- <listitem>
- Plug the 8-pin end of the programming cable to the
- matching connector on the TeleDongle, 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.
- </listitem>
- <listitem>
- Attach a battery to the TeleMetrum board.
- </listitem>
- <listitem>
- Plug the TeleDongle into your computer's USB port, and power
- up the TeleMetrum.
- </listitem>
- <listitem>
- Run AltosUI, and select 'Flash Image' from the File menu.
- </listitem>
- <listitem>
- Pick the TeleDongle device from the list, identifying it as the
- programming device.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- Hit the 'OK' button and the software should proceed to flash
- the TeleMetrum with new firmware, showing a progress bar.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- If something goes wrong, give it another try.
- </listitem>
- </orderedlist>
- </section>
- <section>
- <title>Updating TeleMini Firmware</title>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- You'll need a special 'programming cable' to reprogram the
- TeleMini. It's available on the Altus Metrum web store, or
- you can make your own using an 8-pin MicroMaTch connector on
- one end and a set of four pins on the other.
- </listitem>
- <listitem>
- Take the 2 screws out of the TeleDongle case to get access
- to the circuit board.
- </listitem>
- <listitem>
- Plug the 8-pin end of the programming cable to the matching
- connector on the TeleDongle, 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.
- </listitem>
- <listitem>
- Attach a battery to the TeleMini board.
- </listitem>
- <listitem>
- Plug the TeleDongle into your computer's USB port, and power
- up the TeleMini
- </listitem>
- <listitem>
- Run AltosUI, and select 'Flash Image' from the File menu.
- </listitem>
- <listitem>
- Pick the TeleDongle device from the list, identifying it as the
- programming device.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- Hit the 'OK' button and the software should proceed to flash
- the TeleMini with new firmware, showing a progress bar.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- If something goes wrong, give it another try.
- </listitem>
- </orderedlist>
- </section>
- <section>
- <title>Updating TeleDongle Firmware</title>
- <para>
- Updating TeleDongle's firmware is just like updating TeleMetrum or TeleMini
- firmware, but you use either a TeleMetrum or another TeleDongle as the programmer.
- </para>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- 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.
- </listitem>
- <listitem>
- 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 or TeleDongle.
- </listitem>
- <listitem>
- Take the 2 screws out of the TeleDongle case to get access
- to the circuit board.
- </listitem>
- <listitem>
- 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.
- 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.
- </listitem>
- <listitem>
- Attach a battery to the TeleMetrum board if you're using one.
- </listitem>
- <listitem>
- Plug both the programmer and the TeleDongle into your computer's USB
- ports, and power up the programmer.
- </listitem>
- <listitem>
- Run AltosUI, and select 'Flash Image' from the File menu.
- </listitem>
- <listitem>
- Pick the programmer device from the list, identifying it as the
- programming device.
- </listitem>
- <listitem>
- Select the image you want put on the TeleDongle, 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.
- </listitem>
- <listitem>
- 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
- 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.
- </listitem>
- <listitem>
- Hit the 'OK' button and the software should proceed to flash
- the TeleDongle with new firmware, showing a progress bar.
- </listitem>
- <listitem>
- Confirm that the TeleDongle 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.
- </listitem>
- <listitem>
- If something goes wrong, give it another try.
- </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>TeleMetrum 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 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 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 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>
- </chapter>
- <chapter>
- <title>FAQ</title>
- <para>
- TeleMetrum seems to shut off when disconnected from the
- computer. 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>
- It's impossible to stop the TeleDongle when it's in "p" mode, I have
- to unplug the USB cable? 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>
- The amber LED (on the TeleMetrum) lights up when both
- battery and USB are connected. Does this mean it's charging?
- 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>
- There are no "dit-dah-dah-dit" sound or lights like the manual mentions?
- That's the "pad" mode. Weak batteries might be the problem.
- It is also possible that the TeleMetrum 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>
- How do I save flight data?
- 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. 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 DataFlash chip.
- </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>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>
- <mediaobject id="TeleMetrumTemplate">
- <imageobject>
- <imagedata format="SVG" fileref="telemetrum.svg"/>
- </imageobject>
- </mediaobject>
- </section>
- <section>
- <title>TeleMini 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>
- <mediaobject id="TeleMiniTemplate">
- <imageobject>
- <imagedata format="SVG" fileref="telemini.svg"/>
- </imageobject>
- </mediaobject>
- </section>
- </appendix>
- <appendix>
- <title>Calibration</title>
- <para>
- There are only two calibrations required for a TeleMetrum board, and
- only one for TeleDongle and TeleMini. 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 48 MHz
- 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 TeleMetrum, this is best done over USB. For TeleMini,
- 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 DataFlash 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 Accelerometer</title>
- <para>
- The TeleMetrum accelerometer we use has its own 5 volt power
- supply and
- the output must be passed through a resistive voltage divider to match
- the input of our 3.3 volt ADC. This means that unlike the barometric
- sensor, the output of the acceleration sensor is not ratio-metric to
- the ADC converter, and calibration is required. Explicitly
- calibrating the accelerometers also allows us to load any device
- from a Freescale family that includes at least +/- 40g, 50g, 100g,
- and 200g parts. Using gravity,
- a simple 2-point calibration yields acceptable results capturing both
- the different sensitivities and ranges of the different accelerometer
- parts and any variation in power supply voltages or resistor values
- in the divider network.
- </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 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
- xmlns:xi="http://www.w3.org/2001/XInclude">
- <title>Release Notes</title>
- <simplesect><title>Version 1.2</title><xi:include href="release-notes-1.2.xsl" xpointer="xpointer(/article/*)"/></simplesect>
- <simplesect><title>Version 1.1.1</title><xi:include href="release-notes-1.1.1.xsl" xpointer="xpointer(/article/*)"/></simplesect>
- <simplesect><title>Version 1.1</title><xi:include href="release-notes-1.1.xsl" xpointer="xpointer(/article/*)"/></simplesect>
- <simplesect><title>Version 1.0.1</title><xi:include href="release-notes-1.0.1.xsl" xpointer="xpointer(/article/*)"/></simplesect>
- <simplesect><title>Version 0.9.2</title><xi:include href="release-notes-0.9.2.xsl" xpointer="xpointer(/article/*)"/></simplesect>
- <simplesect><title>Version 0.9</title><xi:include href="release-notes-0.9.xsl" xpointer="xpointer(/article/*)"/></simplesect>
- <simplesect><title>Version 0.8</title><xi:include href="release-notes-0.8.xsl" xpointer="xpointer(/article/*)"/></simplesect>
- <simplesect><title>Version 0.7.1</title><xi:include href="release-notes-0.7.1.xsl" xpointer="xpointer(/article/*)"/></simplesect>
- </appendix>
-</book>
-
-<!-- LocalWords: Altusmetrum
--->
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