-<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>TeleMetrum</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="book" title="TeleMetrum"><div class="titlepage"><div><div><h1 class="title"><a name="id2
681233"></a>TeleMetrum</h1></div><div><h2 class="subtitle">Owner's Manual for the TeleMetrum System</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Bdale</span> <span class="surname">Garbee</span></h3></div></div><div><div class="author"><h3 class="author"><span class="firstname">Keith</span> <span class="surname">Packard</span></h3></div></div><div><p class="copyright">Copyright © 2010 Bdale Garbee and Keith Packard</p></div><div><div class="legalnotice" title="Legal Notice"><a name="id2964839"></a><p>
+<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>TeleMetrum</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="book" title="TeleMetrum"><div class="titlepage"><div><div><h1 class="title"><a name="id2
377993"></a>TeleMetrum</h1></div><div><h2 class="subtitle">Owner's Manual for the TeleMetrum System</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Bdale</span> <span class="surname">Garbee</span></h3></div></div><div><div class="author"><h3 class="author"><span class="firstname">Keith</span> <span class="surname">Packard</span></h3></div></div><div><p class="copyright">Copyright © 2010 Bdale Garbee and Keith Packard</p></div><div><div class="legalnotice" title="Legal Notice"><a name="id2661598"></a><p>
This document is released under the terms of the
<a class="ulink" href="http://creativecommons.org/licenses/by-sa/3.0/" target="_top">
Creative Commons ShareAlike 3.0
</a>
license.
- </p></div></div><div><div class="revhistory"><table border="1" width="100%" summary="Revision history"><tr><th align="left" valign="top" colspan="2"><b>Revision History</b></th></tr><tr><td align="left">Revision 0.1</td><td align="left">30 March 2010</td></tr><tr><td align="left" colspan="2">Initial content</td></tr></table></div></div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="chapter"><a href="#id2961261">1. Introduction and Overview</a></span></dt><dt><span class="chapter"><a href="#id2945012">2. Getting Started</a></span></dt><dd><dl><dt><span class="section"><a href="#id2969939">FAQ</a></span></dt></dl></dd><dt><span class="chapter"><a href="#id2963754">3. Specifications</a></span></dt><dt><span class="chapter"><a href="#id2965995">4. Handling Precautions</a></span></dt><dt><span class="chapter"><a href="#id2979951">5. Hardware Overview</a></span></dt><dt><span class="chapter"><a href="#id2980270">6. Operation</a></span></dt><dd><dl><dt><span class="section"><a href="#id2966264">Firmware Modes </a></span></dt><dt><span class="section"><a href="#id2965911">GPS </a></span></dt><dt><span class="section"><a href="#id2977993">Ground Testing </a></span></dt><dt><span class="section"><a href="#id2962884">Radio Link </a></span></dt><dt><span class="section"><a href="#id2960257">Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#id2955134">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2948360">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2982412">Main Deployment Altitude</a></span></dt></dl></dd><dt><span class="section"><a href="#id2969053">Calibration</a></span></dt><dd><dl><dt><span class="section"><a href="#id2969214">Radio Frequency</a></span></dt><dt><span class="section"><a href="#id2975078">Accelerometer</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#id2976467">7. Using Altus Metrum Products</a></span></dt><dd><dl><dt><span class="section"><a href="#id2964669">Being Legal</a></span></dt><dd><dl><dt><span class="section"><a href="#id2969459">In the Rocket</a></span></dt><dt><span class="section"><a href="#id2964682">On the Ground</a></span></dt><dt><span class="section"><a href="#id2980718">Data Analysis</a></span></dt><dt><span class="section"><a href="#id2957709">Future Plans</a></span></dt></dl></dd><dt><span class="section"><a href="#id2961256">
+ </p></div></div><div><div class="revhistory"><table border="1" width="100%" summary="Revision history"><tr><th align="left" valign="top" colspan="2"><b>Revision History</b></th></tr><tr><td align="left">Revision 0.2</td><td align="left">18 July 2010</td></tr><tr><td align="left" colspan="2">Significant update</td></tr><tr><td align="left">Revision 0.1</td><td align="left">30 March 2010</td></tr><tr><td align="left" colspan="2">Initial content</td></tr></table></div></div></div><hr></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="chapter"><a href="#id2641275">1. Introduction and Overview</a></span></dt><dt><span class="chapter"><a href="#id2656912">2. Getting Started</a></span></dt><dd><dl><dt><span class="section"><a href="#id2675548">FAQ</a></span></dt></dl></dd><dt><span class="chapter"><a href="#id2675022">3. Specifications</a></span></dt><dt><span class="chapter"><a href="#id2668775">4. Handling Precautions</a></span></dt><dt><span class="chapter"><a href="#id2640995">5. Hardware Overview</a></span></dt><dt><span class="chapter"><a href="#id2648902">6. Operation</a></span></dt><dd><dl><dt><span class="section"><a href="#id2645726">Firmware Modes </a></span></dt><dt><span class="section"><a href="#id2644773">GPS </a></span></dt><dt><span class="section"><a href="#id2659643">Ground Testing </a></span></dt><dt><span class="section"><a href="#id2657017">Radio Link </a></span></dt><dt><span class="section"><a href="#id2660834">Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#id2657184">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2665037">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2670409">Main Deployment Altitude</a></span></dt></dl></dd><dt><span class="section"><a href="#id2666172">Calibration</a></span></dt><dd><dl><dt><span class="section"><a href="#id2676235">Radio Frequency</a></span></dt><dt><span class="section"><a href="#id2676108">Accelerometer</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#id2653312">7. Using Altus Metrum Products</a></span></dt><dd><dl><dt><span class="section"><a href="#id2645409">Being Legal</a></span></dt><dd><dl><dt><span class="section"><a href="#id2652849">In the Rocket</a></span></dt><dt><span class="section"><a href="#id2677187">On the Ground</a></span></dt><dt><span class="section"><a href="#id2679244">Data Analysis</a></span></dt><dt><span class="section"><a href="#id2668578">Future Plans</a></span></dt></dl></dd><dt><span class="section"><a href="#id2653941">
How GPS Works
- </a></span></dt></dl></dd></dl></div><div class="chapter" title="Chapter 1. Introduction and Overview"><div class="titlepage"><div><div><h2 class="title"><a name="id2
961261"></a>Chapter 1. Introduction and Overview</h2></div></div></div><p>
+ </a></span></dt></dl></dd></dl></div><div class="chapter" title="Chapter 1. Introduction and Overview"><div class="titlepage"><div><div><h2 class="title"><a name="id2
641275"></a>Chapter 1. Introduction and Overview</h2></div></div></div><p>
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
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.
- </p></div><div class="chapter" title="Chapter 2. Getting Started"><div class="titlepage"><div><div><h2 class="title"><a name="id2945012"></a>Chapter 2. Getting Started</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#id2969939">FAQ</a></span></dt></dl></div><p>
+ </p><p>
+ 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.
+ </p></div><div class="chapter" title="Chapter 2. Getting Started"><div class="titlepage"><div><div><h2 class="title"><a name="id2656912"></a>Chapter 2. Getting Started</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#id2675548">FAQ</a></span></dt></dl></div><p>
This chapter began as "The Mere-Mortals Quick Start/Usage Guide to
the Altus Metrum Starter Kit" by Bob Finch, W9YA, NAR 12965, TRA 12350,
w9ya@amsat.org. Bob was one of our first customers for a production
</p><p>
When you have successfully installed the software suite (either from
compiled source code or as the pre-built Debian package) you will
- have 10 executable programs all of which have names beginning with 'ao-'.
- ('ao-view' is the lone GUI-based program.
- The rest are command-line based.) You will also
- have 10 man pages, that give you basic info on each program.
- And you will also get this documentation in two file types,
- telemetrum.pdf and telemetrum.html.
- Finally you will have a couple of control files that allow the ao-view
+ have 10 or so executable programs all of which have names beginning
+ with 'ao-'.
+ ('ao-view' is the lone GUI-based program, the rest are command-line
+ oriented.) You will also have man pages, that give you basic info
+ on each program.
+ You will also get this documentation in two file types in the doc/
+directory, telemetrum-doc.pdf and telemetrum-doc.html.
+ Finally you will have a couple control files that allow the ao-view
GUI-based program to appear in your menu of programs (under
the 'Internet' category).
</p><p>
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 (I use konsole for this,) to see what
- port-device-name each device has been assigned by the operating system.
+ '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.
second use will be outlined later.
</p><p>
Both TeleMetrum and TeleDongle share the concept of a two level
- command set in their
- firmware. The first layer has several single letter commands. Once
+ 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
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, 'cu' (and possibly 'cutecom') For instance, try to send
- (type) a 'cr2' and verify the channel change by sending a 'cs'.
- Verify you can connect and disconnect from the units while in 'cu'
- by sending the escape-disconnect mentioned above.
+ 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.
</p><p>
Note that the 'reboot' command, which is very useful on TeleMetrum,
will likely just cause problems with the dongle. The *correct* way
</p><p>
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. Mostly you just use
+ 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!
- </p><div class="section" title="FAQ"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
969939"></a>FAQ</h2></div></div></div><p>
+ </p><div class="section" title="FAQ"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
675548"></a>FAQ</h2></div></div></div><p>
The altimeter (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
unlike the rf-linked .telem files that are subject to the
turnarounds/data-packaging time slots in the half-duplex rf data path.
See the above instructions on what and how to save the eeprom stored
- data after physically retrieving your TeleMetrum.
- </p></div></div><div class="chapter" title="Chapter 3. Specifications"><div class="titlepage"><div><div><h2 class="title"><a name="id2963754"></a>Chapter 3. Specifications</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
+ data after physically retrieving your TeleMetrum. Make sure to save
+ the on-board data after each flight, as the current firmware will
+ over-write any previous flight data during a new flight.
+ </p></div></div><div class="chapter" title="Chapter 3. Specifications"><div class="titlepage"><div><div><h2 class="title"><a name="id2675022"></a>Chapter 3. Specifications</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
Recording altimeter for model rocketry.
</p></li><li class="listitem"><p>
Supports dual deployment (can fire 2 ejection charges).
battery if needed.
</p></li><li class="listitem"><p>
2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube.
- </p></li></ul></div></div><div class="chapter" title="Chapter 4. Handling Precautions"><div class="titlepage"><div><div><h2 class="title"><a name="id2
965995"></a>Chapter 4. Handling Precautions</h2></div></div></div><p>
+ </p></li></ul></div></div><div class="chapter" title="Chapter 4. Handling Precautions"><div class="titlepage"><div><div><h2 class="title"><a name="id2
668775"></a>Chapter 4. Handling Precautions</h2></div></div></div><p>
TeleMetrum is a sophisticated electronic device. When handled gently and
properly installed in an airframe, it will deliver impressive results.
However, like all electronic devices, there are some precautions you
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 a 29mm airframe's see-through
- plastic payload bay.
+ designing an installation, for example, in a 29mm airframe with a
+ see-through plastic payload bay.
</p><p>
- The TeleMetrum barometric sensor sampling port must be able to "breathe",
+ The TeleMetrum 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, but also by having a
suitable static vent to outside air.
</p><p>
As with all other rocketry electronics, TeleMetrum must be protected
from exposure to corrosive motor exhaust and ejection charge gasses.
- </p></div><div class="chapter" title="Chapter 5. Hardware Overview"><div class="titlepage"><div><div><h2 class="title"><a name="id2
979951"></a>Chapter 5. Hardware Overview</h2></div></div></div><p>
+ </p></div><div class="chapter" title="Chapter 5. Hardware Overview"><div class="titlepage"><div><div><h2 class="title"><a name="id2
640995"></a>Chapter 5. Hardware Overview</h2></div></div></div><p>
TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to
fit inside coupler for 29mm airframe tubing, but using it in a tube that
small in diameter may require some creativity in mounting and wiring
connectors. If the airframe will not support this much height or if
you want to be able to directly attach e-match leads to the board, we
offer a screw terminal block. This is very similar to what most other
- altimeter vendors provide and so may be the most familiar
- option. You'll need a very small straight blade screwdriver to connect
+ altimeter vendors provide and so may be the most familiar option.
+ You'll need a very small straight blade screwdriver to connect
and disconnect the board in this case, such as you might find in a
jeweler's screwdriver set. Finally, you can forego both options and
solder wires directly to the board, which may be the best choice for
TeleMetrum with an SMA connector for the UHF antenna connection, and
you can unplug the integrated GPS antenna and select an appropriate
off-board GPS antenna with cable terminating in a U.FL connector.
- </p></div><div class="chapter" title="Chapter 6. Operation"><div class="titlepage"><div><div><h2 class="title"><a name="id2
980270"></a>Chapter 6. Operation</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#id2966264">Firmware Modes </a></span></dt><dt><span class="section"><a href="#id2965911">GPS </a></span></dt><dt><span class="section"><a href="#id2977993">Ground Testing </a></span></dt><dt><span class="section"><a href="#id2962884">Radio Link </a></span></dt><dt><span class="section"><a href="#id2960257">Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#id2955134">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2948360">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2982412">Main Deployment Altitude</a></span></dt></dl></dd><dt><span class="section"><a href="#id2969053">Calibration</a></span></dt><dd><dl><dt><span class="section"><a href="#id2969214">Radio Frequency</a></span></dt><dt><span class="section"><a href="#id2975078">Accelerometer</a></span></dt></dl></dd></dl></div><div class="section" title="Firmware Modes"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2966264"></a>Firmware Modes </h2></div></div></div><p>
+ </p></div><div class="chapter" title="Chapter 6. Operation"><div class="titlepage"><div><div><h2 class="title"><a name="id2
648902"></a>Chapter 6. Operation</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#id2645726">Firmware Modes </a></span></dt><dt><span class="section"><a href="#id2644773">GPS </a></span></dt><dt><span class="section"><a href="#id2659643">Ground Testing </a></span></dt><dt><span class="section"><a href="#id2657017">Radio Link </a></span></dt><dt><span class="section"><a href="#id2660834">Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#id2657184">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2665037">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2670409">Main Deployment Altitude</a></span></dt></dl></dd><dt><span class="section"><a href="#id2666172">Calibration</a></span></dt><dd><dl><dt><span class="section"><a href="#id2676235">Radio Frequency</a></span></dt><dt><span class="section"><a href="#id2676108">Accelerometer</a></span></dt></dl></dd></dl></div><div class="section" title="Firmware Modes"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2645726"></a>Firmware Modes </h2></div></div></div><p>
The AltOS firmware build for TeleMetrum has two fundamental modes,
"idle" and "flight". Which of these modes the firmware operates in
is determined by the orientation of the rocket (well, actually the
if the rocket is more or less horizontal, the firmware instead enters
idle mode.
</p><p>
- At power on, you will hear three beeps ("S" in Morse code for startup)
- and then a pause while
+ At power on, you will hear three beeps
+ ("S" in Morse code for startup) and then a pause while
TeleMetrum completes initialization and self tests, and decides which
mode to enter next.
</p><p>
- In flight mode, TeleMetrum turns on the GPS system, engages the flight
+ In flight or "pad" mode, TeleMetrum turns on the GPS system,
+ engages the flight
state machine, goes into transmit-only mode on the RF link sending
telemetry, and waits for launch to be detected. Flight mode is
indicated by an audible "di-dah-dah-dit" ("P" for pad) on the
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!
- </p></div><div class="section" title="GPS"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
965911"></a>GPS </h2></div></div></div><p>
+ </p></div><div class="section" title="GPS"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
644773"></a>GPS </h2></div></div></div><p>
TeleMetrum includes a complete GPS receiver. See a later section for
a brief explanation of how GPS works that will help you understand
the information in the telemetry stream. The bottom line is that
is turned back on, the GPS system should lock very quickly, typically
long before igniter installation and return to the flight line are
complete.
- </p></div><div class="section" title="Ground Testing"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
977993"></a>Ground Testing </h2></div></div></div><p>
+ </p></div><div class="section" title="Ground Testing"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
659643"></a>Ground Testing </h2></div></div></div><p>
An important aspect of preparing a rocket using electronic deployment
for flight is ground testing the recovery system. Thanks
to the bi-directional RF link central to the Altus Metrum system,
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'.
- </p></div><div class="section" title="Radio Link"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
962884"></a>Radio Link </h2></div></div></div><p>
+ </p></div><div class="section" title="Radio Link"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
657017"></a>Radio Link </h2></div></div></div><p>
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
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 a test flight above 12k AGL with good reception, and calculations
- suggest we should be good to 40k AGL or more with a 5-element yagi on
+ had flights to above 21k feet AGL with good 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 soon, and would
of course appreciate customer feedback on performance in higher
altitude flights!
- </p></div><div class="section" title="Configurable Parameters"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
960257"></a>Configurable Parameters</h2></div></div></div><p>
+ </p></div><div class="section" title="Configurable Parameters"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
660834"></a>Configurable Parameters</h2></div></div></div><p>
Configuring a TeleMetrum board for flight is very simple. Because we
have both acceleration and pressure sensors, there is no need to set
a "mach delay", for example. The few configurable parameters can all
be set using a simple terminal program over the USB port or RF link
via TeleDongle.
- </p><div class="section" title="Radio Channel"><div class="titlepage"><div><div><h3 class="title"><a name="id2
955134"></a>Radio Channel</h3></div></div></div><p>
+ </p><div class="section" title="Radio Channel"><div class="titlepage"><div><div><h3 class="title"><a name="id2
657184"></a>Radio Channel</h3></div></div></div><p>
Our firmware supports 10 channels. The default channel 0 corresponds
to a center frequency of 434.550 Mhz, and channels are spaced every
100 khz. Thus, channel 1 is 434.650 Mhz, and channel 9 is 435.550 Mhz.
To set the radio channel, use the 'c r' command, like 'c r 3' to set
channel 3.
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.
- </p></div><div class="section" title="Apogee Delay"><div class="titlepage"><div><div><h3 class="title"><a name="id2948360"></a>Apogee Delay</h3></div></div></div><p>
+ change to the parameter block in the on-board DataFlash chip on
+ your TeleMetrum board if you want the change to stay in place across reboots.
+ </p></div><div class="section" title="Apogee Delay"><div class="titlepage"><div><div><h3 class="title"><a name="id2665037"></a>Apogee Delay</h3></div></div></div><p>
Apogee delay is the number of seconds after TeleMetrum 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
To set the apogee delay, use the [FIXME] 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.
- </p></div><div class="section" title="Main Deployment Altitude"><div class="titlepage"><div><div><h3 class="title"><a name="id2982412"></a>Main Deployment Altitude</h3></div></div></div><p>
+ </p><p>
+ Please note that the TeleMetrum apogee detection algorithm always
+ fires a fraction of a second *after* 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 airframes this way quite happily,
+ including Keith's successful L3 cert.
+ </p></div><div class="section" title="Main Deployment Altitude"><div class="titlepage"><div><div><h3 class="title"><a name="id2670409"></a>Main Deployment Altitude</h3></div></div></div><p>
By default, TeleMetrum 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 airframes, but feel free to change this
To set the main deployment altitude, use the [FIXME] 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.
- </p></div></div><div class="section" title="Calibration"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
969053"></a>Calibration</h2></div></div></div><p>
+ </p></div></div><div class="section" title="Calibration"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
666172"></a>Calibration</h2></div></div></div><p>
There are only two calibrations required for a TeleMetrum board, and
only one for TeleDongle.
- </p><div class="section" title="Radio Frequency"><div class="titlepage"><div><div><h3 class="title"><a name="id2
969214"></a>Radio Frequency</h3></div></div></div><p>
+ </p><div class="section" title="Radio Frequency"><div class="titlepage"><div><div><h3 class="title"><a name="id2
676235"></a>Radio Frequency</h3></div></div></div><p>
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
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.
- </p></div><div class="section" title="Accelerometer"><div class="titlepage"><div><div><h3 class="title"><a name="id2
975078"></a>Accelerometer</h3></div></div></div><p>
+ </p></div><div class="section" title="Accelerometer"><div class="titlepage"><div><div><h3 class="title"><a name="id2
676108"></a>Accelerometer</h3></div></div></div><p>
The 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
Note that we always store and return raw ADC samples for each
sensor... nothing is permanently "lost" or "damaged" if the
calibration is poor.
- </p></div></div></div><div class="chapter" title="Chapter 7. Using Altus Metrum Products"><div class="titlepage"><div><div><h2 class="title"><a name="id2976467"></a>Chapter 7. Using Altus Metrum Products</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#id2964669">Being Legal</a></span></dt><dd><dl><dt><span class="section"><a href="#id2969459">In the Rocket</a></span></dt><dt><span class="section"><a href="#id2964682">On the Ground</a></span></dt><dt><span class="section"><a href="#id2980718">Data Analysis</a></span></dt><dt><span class="section"><a href="#id2957709">Future Plans</a></span></dt></dl></dd><dt><span class="section"><a href="#id2961256">
+ </p></div></div></div><div class="chapter" title="Chapter 7. Using Altus Metrum Products"><div class="titlepage"><div><div><h2 class="title"><a name="id2653312"></a>Chapter 7. Using Altus Metrum Products</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#id2645409">Being Legal</a></span></dt><dd><dl><dt><span class="section"><a href="#id2652849">In the Rocket</a></span></dt><dt><span class="section"><a href="#id2677187">On the Ground</a></span></dt><dt><span class="section"><a href="#id2679244">Data Analysis</a></span></dt><dt><span class="section"><a href="#id2668578">Future Plans</a></span></dt></dl></dd><dt><span class="section"><a href="#id2653941">
How GPS Works
- </a></span></dt></dl></div><div class="section" title="Being Legal"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
964669"></a>Being Legal</h2></div></div></div><p>
+ </a></span></dt></dl></div><div class="section" title="Being Legal"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2
645409"></a>Being Legal</h2></div></div></div><p>
First off, in the US, you need an [amateur radio license](../Radio) or
other authorization to legally operate the radio transmitters that are part
of our products.
- </p><div class="section" title="In the Rocket"><div class="titlepage"><div><div><h3 class="title"><a name="id2
969459"></a>In the Rocket</h3></div></div></div><p>
+ </p><div class="section" title="In the Rocket"><div class="titlepage"><div><div><h3 class="title"><a name="id2
652849"></a>In the Rocket</h3></div></div></div><p>
In the rocket itself, you just need a [TeleMetrum](../TeleMetrum) board and
a LiPo rechargeable battery. An 860mAh battery weighs less than a 9V
alkaline battery, and will run a [TeleMetrum](../TeleMetrum) for hours.
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.
- </p></div><div class="section" title="On the Ground"><div class="titlepage"><div><div><h3 class="title"><a name="id2
964682"></a>On the Ground</h3></div></div></div><p>
+ </p></div><div class="section" title="On the Ground"><div class="titlepage"><div><div><h3 class="title"><a name="id2
677187"></a>On the Ground</h3></div></div></div><p>
To receive the data stream from the rocket, you need an antenna and short
feedline connected to one of our [TeleDongle](../TeleDongle) units. The
TeleDongle in turn plugs directly into the USB port on a notebook
</a>
The 440-3 and 440-5 are both good choices for finding a
TeleMetrum-equipped rocket when used with a suitable 70cm HT.
- </p></div><div class="section" title="Data Analysis"><div class="titlepage"><div><div><h3 class="title"><a name="id2
980718"></a>Data Analysis</h3></div></div></div><p>
+ </p></div><div class="section" title="Data Analysis"><div class="titlepage"><div><div><h3 class="title"><a name="id2
679244"></a>Data Analysis</h3></div></div></div><p>
Our software makes it easy to log the data from each flight, both the
telemetry received over the RF link during the flight itself, and the more
complete data log recorded in the DataFlash memory on the TeleMetrum
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.
- </p></div><div class="section" title="Future Plans"><div class="titlepage"><div><div><h3 class="title"><a name="id2
957709"></a>Future Plans</h3></div></div></div><p>
+ </p></div><div class="section" title="Future Plans"><div class="titlepage"><div><div><h3 class="title"><a name="id2
668578"></a>Future Plans</h3></div></div></div><p>
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. A reference design for a companion board will be documented
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...
- </p></div></div><div class="section" title="How GPS Works"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2961256"></a>
+ </p></div></div><div class="section" title="How GPS Works"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2653941"></a>
How GPS Works
</h2></div></div></div><p>
Placeholder.
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