1 <html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>The Altus Metrum System</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="The Altus Metrum System"><div class="titlepage"><div><div><h1 class="title"><a name="id2285355"></a>The Altus Metrum System</h1></div><div><h2 class="subtitle">An Owner's Manual for TeleMetrum and TeleDongle Devices</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><div class="author"><h3 class="author"><span class="firstname">Bob</span> <span class="surname">Finch</span></h3></div></div><div><div class="author"><h3 class="author"><span class="firstname">Anthony</span> <span class="surname">Towns</span></h3></div></div><div><p class="copyright">Copyright © 2011 Bdale Garbee and Keith Packard</p></div><div><div class="legalnotice" title="Legal Notice"><a name="id2560854"></a><p>
2 This document is released under the terms of the
3 <a class="ulink" href="http://creativecommons.org/licenses/by-sa/3.0/" target="_top">
4 Creative Commons ShareAlike 3.0
7 </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 0.9.2</td><td align="left">19 March 2011</td></tr><tr><td align="left" colspan="2">
8 Updated for software version 0.9.2. This version has minor
9 updates to the AltosUI code to fix graphing on Mac OS X and
10 make flight data download more reliable. It is otherwise
11 completely compatible with version 0.9.
12 </td></tr><tr><td align="left">Revision 0.9</td><td align="left">18 January 2011</td></tr><tr><td align="left" colspan="2">
13 Updated for software version 0.9. Note that 0.9 represents a
14 telemetry format change, meaning both ends of a link (TeleMetrum and
15 TeleDongle) must be updated or communications will fail.
16 </td></tr></table></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 0.8</td><td align="left">24 November 2010</td></tr><tr><td align="left" colspan="2">Updated for software version 0.8 </td></tr></table></div></div></div><hr></div><div class="acknowledgements" title="Acknowledgements"><div class="titlepage"><div><div><h2 class="title"><a name="id2561425"></a>Acknowledgements</h2></div></div></div>
18 Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing "The
19 Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter
20 Kit" which has turned into the Getting Started chapter in this
21 book. Bob was one of our first customers for a production
22 TeleMetrum, and the enthusiasm that led to his contribution of
23 this section is immensely gratifying and highy appreciated!
26 And thanks to Anthony (AJ) Towns for contributing the
27 AltosUI graphing and site map code and documentation. Free
28 software means that our customers and friends can become our
29 collaborators, and we certainly appreciate this level of
33 Have fun using these products, and we hope to meet all of you
34 out on the rocket flight line somewhere.
35 </p><div class="literallayout"><p><br>
36 Bdale Garbee, KB0G<br>
37 NAR #87103, TRA #12201<br>
39 Keith Packard, KD7SQG<br>
40 NAR #88757, TRA #12200<br>
43 </div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="chapter"><a href="#id2529908">1. Introduction and Overview</a></span></dt><dt><span class="chapter"><a href="#id2529949">2. Getting Started</a></span></dt><dd><dl><dt><span class="section"><a href="#id2568943">FAQ</a></span></dt></dl></dd><dt><span class="chapter"><a href="#id2556049">3. Specifications</a></span></dt><dt><span class="chapter"><a href="#id2583902">4. Handling Precautions</a></span></dt><dt><span class="chapter"><a href="#id2556280">5. Hardware Overview</a></span></dt><dt><span class="chapter"><a href="#id2562146">6. System Operation</a></span></dt><dd><dl><dt><span class="section"><a href="#id2565293">Firmware Modes </a></span></dt><dt><span class="section"><a href="#id2567005">GPS </a></span></dt><dt><span class="section"><a href="#id2581409">Ground Testing </a></span></dt><dt><span class="section"><a href="#id2581407">Radio Link </a></span></dt><dt><span class="section"><a href="#id2552127">Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#id2572399">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2563312">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2581119">Main Deployment Altitude</a></span></dt></dl></dd><dt><span class="section"><a href="#id2559748">Calibration</a></span></dt><dd><dl><dt><span class="section"><a href="#id2583470">Radio Frequency</a></span></dt><dt><span class="section"><a href="#id2573580">Accelerometer</a></span></dt></dl></dd><dt><span class="section"><a href="#id2581818">Updating Device Firmware</a></span></dt><dd><dl><dt><span class="section"><a href="#id2554717">Updating TeleMetrum Firmware</a></span></dt><dt><span class="section"><a href="#id2564109">Updating TeleDongle Firmware</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#id2562062">7. AltosUI</a></span></dt><dd><dl><dt><span class="section"><a href="#id2578432">Packet Command Mode</a></span></dt><dt><span class="section"><a href="#id2572301">Monitor Flight</a></span></dt><dd><dl><dt><span class="section"><a href="#id2554918">Launch Pad</a></span></dt><dt><span class="section"><a href="#id2574995">Ascent</a></span></dt><dt><span class="section"><a href="#id2576209">Descent</a></span></dt><dt><span class="section"><a href="#id2561512">Landed</a></span></dt><dt><span class="section"><a href="#id2587026">Site Map</a></span></dt></dl></dd><dt><span class="section"><a href="#id2576446">Save Flight Data</a></span></dt><dt><span class="section"><a href="#id2586529">Replay Flight</a></span></dt><dt><span class="section"><a href="#id2573351">Graph Data</a></span></dt><dt><span class="section"><a href="#id2568352">Export Data</a></span></dt><dd><dl><dt><span class="section"><a href="#id2575553">Comma Separated Value Format</a></span></dt><dt><span class="section"><a href="#id2579115">Keyhole Markup Language (for Google Earth)</a></span></dt></dl></dd><dt><span class="section"><a href="#id2570375">Configure TeleMetrum</a></span></dt><dd><dl><dt><span class="section"><a href="#id2559233">Main Deploy Altitude</a></span></dt><dt><span class="section"><a href="#id2552914">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2582365">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2563940">Radio Calibration</a></span></dt><dt><span class="section"><a href="#id2561819">Callsign</a></span></dt><dt><span class="section"><a href="#id2572471">Maximum Flight Log Size</a></span></dt></dl></dd><dt><span class="section"><a href="#id2564177">Configure AltosUI</a></span></dt><dd><dl><dt><span class="section"><a href="#id2575461">Voice Settings</a></span></dt><dt><span class="section"><a href="#id2573515">Log Directory</a></span></dt><dt><span class="section"><a href="#id2565097">Callsign</a></span></dt><dt><span class="section"><a href="#id2546395">Serial Debug</a></span></dt></dl></dd><dt><span class="section"><a href="#id2575721">Flash Image</a></span></dt><dt><span class="section"><a href="#id2576287">Fire Igniter</a></span></dt></dl></dd><dt><span class="chapter"><a href="#id2570538">8. Using Altus Metrum Products</a></span></dt><dd><dl><dt><span class="section"><a href="#id2576134">Being Legal</a></span></dt><dt><span class="section"><a href="#id2573850">In the Rocket</a></span></dt><dt><span class="section"><a href="#id2572694">On the Ground</a></span></dt><dt><span class="section"><a href="#id2579324">Data Analysis</a></span></dt><dt><span class="section"><a href="#id2585899">Future Plans</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="id2529908"></a>Chapter 1. Introduction and Overview</h2></div></div></div><p>
44 Welcome to the Altus Metrum community! Our circuits and software reflect
45 our passion for both hobby rocketry and Free Software. We hope their
46 capabilities and performance will delight you in every way, but by
47 releasing all of our hardware and software designs under open licenses,
48 we also hope to empower you to take as active a role in our collective
51 The focal point of our community is TeleMetrum, a dual deploy altimeter
52 with fully integrated GPS and radio telemetry as standard features, and
53 a "companion interface" that will support optional capabilities in the
56 Complementing TeleMetrum is TeleDongle, a USB to RF interface for
57 communicating with TeleMetrum. Combined with your choice of antenna and
58 notebook computer, TeleDongle and our associated user interface software
59 form a complete ground station capable of logging and displaying in-flight
60 telemetry, aiding rocket recovery, then processing and archiving flight
61 data for analysis and review.
63 More products will be added to the Altus Metrum family over time, and
64 we currently envision that this will be a single, comprehensive manual
65 for the entire product family.
66 </p></div><div class="chapter" title="Chapter 2. Getting Started"><div class="titlepage"><div><div><h2 class="title"><a name="id2529949"></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="#id2568943">FAQ</a></span></dt></dl></div><p>
67 The first thing to do after you check the inventory of parts in your
68 "starter kit" is to charge the battery by plugging it into the
69 corresponding socket of the TeleMetrum and then using the USB A to
71 cable to plug the Telemetrum into your computer's USB socket. The
72 TeleMetrum circuitry will charge the battery whenever it is plugged
73 in, because the TeleMetrum's on-off switch does NOT control the
74 charging circuitry. When the GPS chip is initially searching for
75 satellites, TeleMetrum will consume more current than it can pull
76 from the usb port, so the battery must be attached in order to get
77 satellite lock. Once GPS is locked, the current consumption goes back
78 down enough to enable charging while
79 running. So it's a good idea to fully charge the battery as your
80 first item of business so there is no issue getting and maintaining
81 satellite lock. The yellow charge indicator led will go out when the
82 battery is nearly full and the charger goes to trickle charge. It
83 can take several hours to fully recharge a deeply discharged battery.
85 The other active device in the starter kit is the TeleDongle USB to
86 RF interface. If you plug it in to your Mac or Linux computer it should
87 "just work", showing up as a serial port device. Windows systems need
88 driver information that is part of the AltOS download to know that the
89 existing USB modem driver will work. If you are using Linux and are
90 having problems, try moving to a fresher kernel (2.6.33 or newer), as
91 the USB serial driver had ugly bugs in some earlier versions.
93 Next you should obtain and install the AltOS utilities. These include
94 the AltosUI ground station program, current firmware images for
95 TeleMetrum and TeleDongle, and a number of standalone utilities that
96 are rarely needed. Pre-built binary packages are available for Debian
97 Linux, Microsoft Windows, and recent MacOSX versions. Full sourcecode
98 and build instructions for some other Linux variants are also available.
99 The latest version may always be downloaded from
100 <a class="ulink" href="http://altusmetrum.org/AltOS" target="_top">http://altusmetrum.org/AltOS</a>.
102 Both Telemetrum and TeleDongle can be directly communicated
103 with using USB ports. The first thing you should try after getting
104 both units plugged into to your computer's usb port(s) is to run
105 'ao-list' from a terminal-window to see what port-device-name each
106 device has been assigned by the operating system.
107 You will need this information to access the devices via their
108 respective on-board firmware and data using other command line
109 programs in the AltOS software suite.
111 To access the device's firmware for configuration you need a terminal
112 program such as you would use to talk to a modem. The software
113 authors prefer using the program 'cu' which comes from the UUCP package
114 on most Unix-like systems such as Linux. An example command line for
115 cu might be 'cu -l /dev/ttyACM0', substituting the correct number
116 indicated from running the
117 ao-list program. Another reasonable terminal program for Linux is
118 'cutecom'. The default 'escape'
119 character used by CU (i.e. the character you use to
120 issue commands to cu itself instead of sending the command as input
121 to the connected device) is a '~'. You will need this for use in
122 only two different ways during normal operations. First is to exit
123 the program by sending a '~.' which is called a 'escape-disconnect'
124 and allows you to close-out from 'cu'. The
125 second use will be outlined later.
127 Both TeleMetrum and TeleDongle share the concept of a two level
128 command set in their firmware.
129 The first layer has several single letter commands. Once
130 you are using 'cu' (or 'cutecom') sending (typing) a '?'
131 returns a full list of these
132 commands. The second level are configuration sub-commands accessed
133 using the 'c' command, for
134 instance typing 'c?' will give you this second level of commands
135 (all of which require the
136 letter 'c' to access). Please note that most configuration options
137 are stored only in DataFlash memory, and only TeleMetrum has this
138 memory to save the various values entered like the channel number
139 and your callsign when powered off. TeleDongle requires that you
140 set these each time you plug it in, which ao-view can help with.
142 Try setting these config ('c' or second level menu) values. A good
143 place to start is by setting your call sign. By default, the boards
144 use 'N0CALL' which is cute, but not exactly legal!
145 Spend a few minutes getting comfortable with the units, their
146 firmware, and 'cu' (or possibly 'cutecom').
147 For instance, try to send
148 (type) a 'c r 2' and verify the channel change by sending a 'c s'.
149 Verify you can connect and disconnect from the units while in your
150 terminal program by sending the escape-disconnect mentioned above.
152 Note that the 'reboot' command, which is very useful on TeleMetrum,
153 will likely just cause problems with the dongle. The *correct* way
154 to reset the dongle is just to unplug and re-plug it.
156 A fun thing to do at the launch site and something you can do while
157 learning how to use these units is to play with the rf-link access
158 of the TeleMetrum from the TeleDongle. Be aware that you *must* create
159 some physical separation between the devices, otherwise the link will
160 not function due to signal overload in the receivers in each device.
162 Now might be a good time to take a break and read the rest of this
163 manual, particularly about the two "modes" that the TeleMetrum
164 can be placed in and how the position of the TeleMetrum when booting
165 up will determine whether the unit is in "pad" or "idle" mode.
167 You can access a TeleMetrum in idle mode from the Teledongle's USB
168 connection using the rf link
169 by issuing a 'p' command to the TeleDongle. Practice connecting and
170 disconnecting ('~~' while using 'cu') from the TeleMetrum. If
171 you cannot escape out of the "p" command, (by using a '~~' when in
172 CU) then it is likely that your kernel has issues. Try a newer version.
174 Using this rf link allows you to configure the TeleMetrum, test
175 fire e-matches and igniters from the flight line, check pyro-match
176 continuity and so forth. You can leave the unit turned on while it
177 is in 'idle mode' and then place the
178 rocket vertically on the launch pad, walk away and then issue a
179 reboot command. The TeleMetrum will reboot and start sending data
180 having changed to the "pad" mode. If the TeleDongle is not receiving
181 this data, you can disconnect 'cu' from the Teledongle using the
182 procedures mentioned above and THEN connect to the TeleDongle from
183 inside 'ao-view'. If this doesn't work, disconnect from the
184 TeleDongle, unplug it, and try again after plugging it back in.
186 Eventually the GPS will find enough satellites, lock in on them,
187 and 'ao-view' will both auditorially announce and visually indicate
189 Now you can launch knowing that you have a good data path and
190 good satellite lock for flight data and recovery. Remember
191 you MUST tell ao-view to connect to the TeleDongle explicitly in
192 order for ao-view to be able to receive data.
194 Both RDF (radio direction finding) tones from the TeleMetrum and
195 GPS trekking data are available and together are very useful in
196 locating the rocket once it has landed. (The last good GPS data
197 received before touch-down will be on the data screen of 'ao-view'.)
199 Once you have recovered the rocket you can download the eeprom
200 contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over
201 either a USB cable or over the radio link using TeleDongle.
202 And by following the man page for 'ao-postflight' you can create
203 various data output reports, graphs, and even kml data to see the
204 flight trajectory in google-earth. (Moving the viewing angle making
205 sure to connect the yellow lines while in google-earth is the proper
208 As for ao-view.... some things are in the menu but don't do anything
209 very useful. The developers have stopped working on ao-view to focus
210 on a new, cross-platform ground station program. So ao-view may or
211 may not be updated in the future. Mostly you just use
212 the Log and Device menus. It has a wonderful display of the incoming
213 flight data and I am sure you will enjoy what it has to say to you
214 once you enable the voice output!
215 </p><div class="section" title="FAQ"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2568943"></a>FAQ</h2></div></div></div><p>
216 The altimeter (TeleMetrum) seems to shut off when disconnected from the
217 computer. Make sure the battery is adequately charged. Remember the
218 unit will pull more power than the USB port can deliver before the
219 GPS enters "locked" mode. The battery charges best when TeleMetrum
222 It's impossible to stop the TeleDongle when it's in "p" mode, I have
223 to unplug the USB cable? Make sure you have tried to "escape out" of
224 this mode. If this doesn't work the reboot procedure for the
225 TeleDongle *is* to simply unplug it. 'cu' however will retain it's
226 outgoing buffer IF your "escape out" ('~~') does not work.
227 At this point using either 'ao-view' (or possibly
228 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
231 The amber LED (on the TeleMetrum/altimeter) lights up when both
232 battery and USB are connected. Does this mean it's charging?
233 Yes, the yellow LED indicates the charging at the 'regular' rate.
234 If the led is out but the unit is still plugged into a USB port,
235 then the battery is being charged at a 'trickle' rate.
237 There are no "dit-dah-dah-dit" sound like the manual mentions?
238 That's the "pad" mode. Weak batteries might be the problem.
239 It is also possible that the unit is horizontal and the output
240 is instead a "dit-dit" meaning 'idle'.
242 It's unclear how to use 'ao-view' and other programs when 'cu'
243 is running. You cannot have more than one program connected to
244 the TeleDongle at one time without apparent data loss as the
245 incoming data will not make it to both programs intact.
246 Disconnect whatever programs aren't currently being used.
248 How do I save flight data?
249 Live telemetry is written to file(s) whenever 'ao-view' is connected
250 to the TeleDongle. The file area defaults to ~/altos
251 but is easily changed using the menus in 'ao-view'. The files that
252 are written end in '.telem'. The after-flight
253 data-dumped files will end in .eeprom and represent continuous data
254 unlike the rf-linked .telem files that are subject to the
255 turnarounds/data-packaging time slots in the half-duplex rf data path.
256 See the above instructions on what and how to save the eeprom stored
257 data after physically retrieving your TeleMetrum. Make sure to save
258 the on-board data after each flight, as the current firmware will
259 over-write any previous flight data during a new flight.
260 </p></div></div><div class="chapter" title="Chapter 3. Specifications"><div class="titlepage"><div><div><h2 class="title"><a name="id2556049"></a>Chapter 3. Specifications</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
261 Recording altimeter for model rocketry.
262 </p></li><li class="listitem"><p>
263 Supports dual deployment (can fire 2 ejection charges).
264 </p></li><li class="listitem"><p>
265 70cm ham-band transceiver for telemetry downlink.
266 </p></li><li class="listitem"><p>
267 Barometric pressure sensor good to 45k feet MSL.
268 </p></li><li class="listitem"><p>
269 1-axis high-g accelerometer for motor characterization, capable of
270 +/- 50g using default part.
271 </p></li><li class="listitem"><p>
272 On-board, integrated GPS receiver with 5hz update rate capability.
273 </p></li><li class="listitem"><p>
274 On-board 1 megabyte non-volatile memory for flight data storage.
275 </p></li><li class="listitem"><p>
276 USB interface for battery charging, configuration, and data recovery.
277 </p></li><li class="listitem"><p>
278 Fully integrated support for LiPo rechargeable batteries.
279 </p></li><li class="listitem"><p>
280 Uses LiPo to fire e-matches, can be modiied to support
281 optional separate pyro battery if needed.
282 </p></li><li class="listitem"><p>
283 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube.
284 </p></li></ul></div></div><div class="chapter" title="Chapter 4. Handling Precautions"><div class="titlepage"><div><div><h2 class="title"><a name="id2583902"></a>Chapter 4. Handling Precautions</h2></div></div></div><p>
285 TeleMetrum is a sophisticated electronic device. When handled gently and
286 properly installed in an airframe, it will deliver impressive results.
287 However, like all electronic devices, there are some precautions you
290 The Lithium Polymer rechargeable batteries used with TeleMetrum have an
291 extraordinary power density. This is great because we can fly with
292 much less battery mass than if we used alkaline batteries or previous
293 generation rechargeable batteries... but if they are punctured
294 or their leads are allowed to short, they can and will release their
296 Thus we recommend that you take some care when handling our batteries
297 and consider giving them some extra protection in your airframe. We
298 often wrap them in suitable scraps of closed-cell packing foam before
299 strapping them down, for example.
301 The TeleMetrum barometric sensor is sensitive to sunlight. In normal
302 mounting situations, it and all of the other surface mount components
303 are "down" towards whatever the underlying mounting surface is, so
304 this is not normally a problem. Please consider this, though, when
305 designing an installation, for example, in a 29mm airframe with a
306 see-through plastic payload bay.
308 The TeleMetrum barometric sensor sampling port must be able to
310 both by not being covered by foam or tape or other materials that might
311 directly block the hole on the top of the sensor, but also by having a
312 suitable static vent to outside air.
314 As with all other rocketry electronics, TeleMetrum must be protected
315 from exposure to corrosive motor exhaust and ejection charge gasses.
316 </p></div><div class="chapter" title="Chapter 5. Hardware Overview"><div class="titlepage"><div><div><h2 class="title"><a name="id2556280"></a>Chapter 5. Hardware Overview</h2></div></div></div><p>
317 TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to
318 fit inside coupler for 29mm airframe tubing, but using it in a tube that
319 small in diameter may require some creativity in mounting and wiring
320 to succeed! The default 1/4
321 wave UHF wire antenna attached to the center of the nose-cone end of
322 the board is about 7 inches long, and wiring for a power switch and
323 the e-matches for apogee and main ejection charges depart from the
324 fin can end of the board. Given all this, an ideal "simple" avionics
325 bay for TeleMetrum should have at least 10 inches of interior length.
327 A typical TeleMetrum installation using the on-board GPS antenna and
328 default wire UHF antenna involves attaching only a suitable
329 Lithium Polymer battery, a single pole switch for power on/off, and
330 two pairs of wires connecting e-matches for the apogee and main ejection
333 By default, we use the unregulated output of the LiPo battery directly
334 to fire ejection charges. This works marvelously with standard
335 low-current e-matches like the J-Tek from MJG Technologies, and with
336 Quest Q2G2 igniters. However, if you
337 want or need to use a separate pyro battery, the board can be factory
338 modified to do so. This involves cutting two traces and adding a jumper
339 in a densely populated part of the board on TeleMetrum v1.0 and v1.1,
340 along with installation of a pyro battery connector at location B2.
342 We offer two choices of pyro and power switch connector, or you can
343 choose neither and solder wires directly to the board. All three choices
344 are reasonable depending on the constraints of your airframe. Our
345 favorite option when there is sufficient room above the board is to use
346 the Tyco pin header with polarization and locking. If you choose this
347 option, you crimp individual wires for the power switch and e-matches
348 into a mating connector, and installing and removing the TeleMetrum
349 board from an airframe is as easy as plugging or unplugging two
350 connectors. If the airframe will not support this much height or if
351 you want to be able to directly attach e-match leads to the board, we
352 offer a screw terminal block. This is very similar to what most other
353 altimeter vendors provide and so may be the most familiar option.
354 You'll need a very small straight blade screwdriver to connect
355 and disconnect the board in this case, such as you might find in a
356 jeweler's screwdriver set. Finally, you can forego both options and
357 solder wires directly to the board, which may be the best choice for
358 minimum diameter and/or minimum mass designs.
360 For most airframes, the integrated GPS antenna and wire UHF antenna are
361 a great combination. However, if you are installing in a carbon-fiber
362 electronics bay which is opaque to RF signals, you may need to use
363 off-board external antennas instead. In this case, you can order
364 TeleMetrum with an SMA connector for the UHF antenna connection, and
365 you can unplug the integrated GPS antenna and select an appropriate
366 off-board GPS antenna with cable terminating in a U.FL connector.
367 </p></div><div class="chapter" title="Chapter 6. System Operation"><div class="titlepage"><div><div><h2 class="title"><a name="id2562146"></a>Chapter 6. System Operation</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#id2565293">Firmware Modes </a></span></dt><dt><span class="section"><a href="#id2567005">GPS </a></span></dt><dt><span class="section"><a href="#id2581409">Ground Testing </a></span></dt><dt><span class="section"><a href="#id2581407">Radio Link </a></span></dt><dt><span class="section"><a href="#id2552127">Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#id2572399">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2563312">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2581119">Main Deployment Altitude</a></span></dt></dl></dd><dt><span class="section"><a href="#id2559748">Calibration</a></span></dt><dd><dl><dt><span class="section"><a href="#id2583470">Radio Frequency</a></span></dt><dt><span class="section"><a href="#id2573580">Accelerometer</a></span></dt></dl></dd><dt><span class="section"><a href="#id2581818">Updating Device Firmware</a></span></dt><dd><dl><dt><span class="section"><a href="#id2554717">Updating TeleMetrum Firmware</a></span></dt><dt><span class="section"><a href="#id2564109">Updating TeleDongle Firmware</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="id2565293"></a>Firmware Modes </h2></div></div></div><p>
368 The AltOS firmware build for TeleMetrum has two fundamental modes,
369 "idle" and "flight". Which of these modes the firmware operates in
370 is determined by the orientation of the rocket (well, actually the
371 board, of course...) at the time power is switched on. If the rocket
372 is "nose up", then TeleMetrum assumes it's on a rail or rod being
373 prepared for launch, so the firmware chooses flight mode. However,
374 if the rocket is more or less horizontal, the firmware instead enters
377 At power on, you will hear three beeps
378 ("S" in Morse code for startup) and then a pause while
379 TeleMetrum completes initialization and self tests, and decides which
382 In flight or "pad" mode, TeleMetrum turns on the GPS system,
384 state machine, goes into transmit-only mode on the RF link sending
385 telemetry, and waits for launch to be detected. Flight mode is
386 indicated by an audible "di-dah-dah-dit" ("P" for pad) on the
388 beeps indicating the state of the pyrotechnic igniter continuity.
389 One beep indicates apogee continuity, two beeps indicate
390 main continuity, three beeps indicate both apogee and main continuity,
391 and one longer "brap" sound indicates no continuity. For a dual
392 deploy flight, make sure you're getting three beeps before launching!
393 For apogee-only or motor eject flights, do what makes sense.
395 In idle mode, you will hear an audible "di-dit" ("I" for idle), and
396 the normal flight state machine is disengaged, thus
397 no ejection charges will fire. TeleMetrum also listens on the RF
398 link when in idle mode for packet mode requests sent from TeleDongle.
399 Commands can be issued to a TeleMetrum in idle mode over either
400 USB or the RF link equivalently.
401 Idle mode is useful for configuring TeleMetrum, for extracting data
402 from the on-board storage chip after flight, and for ground testing
405 One "neat trick" of particular value when TeleMetrum is used with very
406 large airframes, is that you can power the board up while the rocket
407 is horizontal, such that it comes up in idle mode. Then you can
408 raise the airframe to launch position, use a TeleDongle to open
409 a packet connection, and issue a 'reset' command which will cause
410 TeleMetrum to reboot, realize it's now nose-up, and thus choose
411 flight mode. This is much safer than standing on the top step of a
412 rickety step-ladder or hanging off the side of a launch tower with
413 a screw-driver trying to turn on your avionics before installing
415 </p></div><div class="section" title="GPS"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2567005"></a>GPS </h2></div></div></div><p>
416 TeleMetrum includes a complete GPS receiver. See a later section for
417 a brief explanation of how GPS works that will help you understand
418 the information in the telemetry stream. The bottom line is that
419 the TeleMetrum GPS receiver needs to lock onto at least four
420 satellites to obtain a solid 3 dimensional position fix and know
423 TeleMetrum provides backup power to the GPS chip any time a LiPo
424 battery is connected. This allows the receiver to "warm start" on
425 the launch rail much faster than if every power-on were a "cold start"
426 for the GPS receiver. In typical operations, powering up TeleMetrum
427 on the flight line in idle mode while performing final airframe
428 preparation will be sufficient to allow the GPS receiver to cold
429 start and acquire lock. Then the board can be powered down during
430 RSO review and installation on a launch rod or rail. When the board
431 is turned back on, the GPS system should lock very quickly, typically
432 long before igniter installation and return to the flight line are
434 </p></div><div class="section" title="Ground Testing"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2581409"></a>Ground Testing </h2></div></div></div><p>
435 An important aspect of preparing a rocket using electronic deployment
436 for flight is ground testing the recovery system. Thanks
437 to the bi-directional RF link central to the Altus Metrum system,
438 this can be accomplished in a TeleMetrum-equipped rocket without as
439 much work as you may be accustomed to with other systems. It can
442 Just prep the rocket for flight, then power up TeleMetrum while the
443 airframe is horizontal. This will cause the firmware to go into
444 "idle" mode, in which the normal flight state machine is disabled and
445 charges will not fire without manual command. Then, establish an
446 RF packet connection from a TeleDongle-equipped computer using the
447 P command from a safe distance. You can now command TeleMetrum to
448 fire the apogee or main charges to complete your testing.
450 In order to reduce the chance of accidental firing of pyrotechnic
451 charges, the command to fire a charge is intentionally somewhat
452 difficult to type, and the built-in help is slightly cryptic to
453 prevent accidental echoing of characters from the help text back at
454 the board from firing a charge. The command to fire the apogee
455 drogue charge is 'i DoIt drogue' and the command to fire the main
456 charge is 'i DoIt main'.
457 </p></div><div class="section" title="Radio Link"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2581407"></a>Radio Link </h2></div></div></div><p>
458 The chip our boards are based on incorporates an RF transceiver, but
459 it's not a full duplex system... each end can only be transmitting or
460 receiving at any given moment. So we had to decide how to manage the
463 By design, TeleMetrum firmware listens for an RF connection when
464 it's in "idle mode" (turned on while the rocket is horizontal), which
465 allows us to use the RF link to configure the rocket, do things like
466 ejection tests, and extract data after a flight without having to
467 crack open the airframe. However, when the board is in "flight
468 mode" (turned on when the rocket is vertical) the TeleMetrum only
469 transmits and doesn't listen at all. That's because we want to put
470 ultimate priority on event detection and getting telemetry out of
471 the rocket and out over
472 the RF link in case the rocket crashes and we aren't able to extract
475 We don't use a 'normal packet radio' mode because they're just too
476 inefficient. The GFSK modulation we use is just FSK with the
477 baseband pulses passed through a
478 Gaussian filter before they go into the modulator to limit the
479 transmitted bandwidth. When combined with the hardware forward error
480 correction support in the cc1111 chip, this allows us to have a very
481 robust 38.4 kilobit data link with only 10 milliwatts of transmit power,
482 a whip antenna in the rocket, and a hand-held Yagi on the ground. We've
483 had flights to above 21k feet AGL with good reception, and calculations
484 suggest we should be good to well over 40k feet AGL with a 5-element yagi on
485 the ground. We hope to fly boards to higher altitudes soon, and would
486 of course appreciate customer feedback on performance in higher
488 </p></div><div class="section" title="Configurable Parameters"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2552127"></a>Configurable Parameters</h2></div></div></div><p>
489 Configuring a TeleMetrum board for flight is very simple. Because we
490 have both acceleration and pressure sensors, there is no need to set
491 a "mach delay", for example. The few configurable parameters can all
492 be set using a simple terminal program over the USB port or RF link
494 </p><div class="section" title="Radio Channel"><div class="titlepage"><div><div><h3 class="title"><a name="id2572399"></a>Radio Channel</h3></div></div></div><p>
495 Our firmware supports 10 channels. The default channel 0 corresponds
496 to a center frequency of 434.550 Mhz, and channels are spaced every
497 100 khz. Thus, channel 1 is 434.650 Mhz, and channel 9 is 435.550 Mhz.
498 At any given launch, we highly recommend coordinating who will use
499 each channel and when to avoid interference. And of course, both
500 TeleMetrum and TeleDongle must be configured to the same channel to
501 successfully communicate with each other.
503 To set the radio channel, use the 'c r' command, like 'c r 3' to set
505 As with all 'c' sub-commands, follow this with a 'c w' to write the
506 change to the parameter block in the on-board DataFlash chip on
507 your TeleMetrum board if you want the change to stay in place across reboots.
508 </p></div><div class="section" title="Apogee Delay"><div class="titlepage"><div><div><h3 class="title"><a name="id2563312"></a>Apogee Delay</h3></div></div></div><p>
509 Apogee delay is the number of seconds after TeleMetrum detects flight
510 apogee that the drogue charge should be fired. In most cases, this
511 should be left at the default of 0. However, if you are flying
512 redundant electronics such as for an L3 certification, you may wish
513 to set one of your altimeters to a positive delay so that both
514 primary and backup pyrotechnic charges do not fire simultaneously.
516 To set the apogee delay, use the 'c d' command.
517 As with all 'c' sub-commands, follow this with a 'c w' to write the
518 change to the parameter block in the on-board DataFlash chip.
520 Please note that the TeleMetrum apogee detection algorithm always
521 fires a fraction of a second *after* apogee. If you are also flying
522 an altimeter like the PerfectFlite MAWD, which only supports selecting
523 0 or 1 seconds of apogee delay, you may wish to set the MAWD to 0
524 seconds delay and set the TeleMetrum to fire your backup 2 or 3
525 seconds later to avoid any chance of both charges firing
526 simultaneously. We've flown several airframes this way quite happily,
527 including Keith's successful L3 cert.
528 </p></div><div class="section" title="Main Deployment Altitude"><div class="titlepage"><div><div><h3 class="title"><a name="id2581119"></a>Main Deployment Altitude</h3></div></div></div><p>
529 By default, TeleMetrum will fire the main deployment charge at an
530 elevation of 250 meters (about 820 feet) above ground. We think this
531 is a good elevation for most airframes, but feel free to change this
532 to suit. In particular, if you are flying two altimeters, you may
534 deployment elevation for the backup altimeter to be something lower
535 than the primary so that both pyrotechnic charges don't fire
538 To set the main deployment altitude, use the 'c m' command.
539 As with all 'c' sub-commands, follow this with a 'c w' to write the
540 change to the parameter block in the on-board DataFlash chip.
541 </p></div></div><div class="section" title="Calibration"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2559748"></a>Calibration</h2></div></div></div><p>
542 There are only two calibrations required for a TeleMetrum board, and
543 only one for TeleDongle.
544 </p><div class="section" title="Radio Frequency"><div class="titlepage"><div><div><h3 class="title"><a name="id2583470"></a>Radio Frequency</h3></div></div></div><p>
545 The radio frequency is synthesized from a clock based on the 48 Mhz
546 crystal on the board. The actual frequency of this oscillator must be
547 measured to generate a calibration constant. While our GFSK modulation
548 bandwidth is wide enough to allow boards to communicate even when
549 their oscillators are not on exactly the same frequency, performance
550 is best when they are closely matched.
551 Radio frequency calibration requires a calibrated frequency counter.
552 Fortunately, once set, the variation in frequency due to aging and
553 temperature changes is small enough that re-calibration by customers
554 should generally not be required.
556 To calibrate the radio frequency, connect the UHF antenna port to a
557 frequency counter, set the board to channel 0, and use the 'C'
558 command to generate a CW carrier. Wait for the transmitter temperature
559 to stabilize and the frequency to settle down.
560 Then, divide 434.550 Mhz by the
561 measured frequency and multiply by the current radio cal value show
562 in the 'c s' command. For an unprogrammed board, the default value
563 is 1186611. Take the resulting integer and program it using the 'c f'
564 command. Testing with the 'C' command again should show a carrier
565 within a few tens of Hertz of the intended frequency.
566 As with all 'c' sub-commands, follow this with a 'c w' to write the
567 change to the parameter block in the on-board DataFlash chip.
568 </p></div><div class="section" title="Accelerometer"><div class="titlepage"><div><div><h3 class="title"><a name="id2573580"></a>Accelerometer</h3></div></div></div><p>
569 The accelerometer we use has its own 5 volt power supply and
570 the output must be passed through a resistive voltage divider to match
571 the input of our 3.3 volt ADC. This means that unlike the barometric
572 sensor, the output of the acceleration sensor is not ratiometric to
573 the ADC converter, and calibration is required. We also support the
574 use of any of several accelerometers from a Freescale family that
575 includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity,
576 a simple 2-point calibration yields acceptable results capturing both
577 the different sensitivities and ranges of the different accelerometer
578 parts and any variation in power supply voltages or resistor values
579 in the divider network.
581 To calibrate the acceleration sensor, use the 'c a 0' command. You
582 will be prompted to orient the board vertically with the UHF antenna
583 up and press a key, then to orient the board vertically with the
584 UHF antenna down and press a key.
585 As with all 'c' sub-commands, follow this with a 'c w' to write the
586 change to the parameter block in the on-board DataFlash chip.
588 The +1g and -1g calibration points are included in each telemetry
589 frame and are part of the header extracted by ao-dumplog after flight.
590 Note that we always store and return raw ADC samples for each
591 sensor... nothing is permanently "lost" or "damaged" if the
594 In the unlikely event an accel cal that goes badly, it is possible
595 that TeleMetrum may always come up in 'pad mode' and as such not be
596 listening to either the USB or radio interfaces. If that happens,
597 there is a special hook in the firmware to force the board back
598 in to 'idle mode' so you can re-do the cal. To use this hook, you
599 just need to ground the SPI clock pin at power-on. This pin is
600 available as pin 2 on the 8-pin companion connector, and pin 1 is
601 ground. So either carefully install a fine-gauge wire jumper
602 between the two pins closest to the index hole end of the 8-pin
603 connector, or plug in the programming cable to the 8-pin connector
604 and use a small screwdriver or similar to short the two pins closest
605 to the index post on the 4-pin end of the programming cable, and
606 power up the board. It should come up in 'idle mode' (two beeps).
607 </p></div></div><div class="section" title="Updating Device Firmware"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2581818"></a>Updating Device Firmware</h2></div></div></div><p>
608 The big conceptual thing to realize is that you have to use a
609 TeleDongle as a programmer to update a TeleMetrum, and vice versa.
610 Due to limited memory resources in the cc1111, we don't support
611 programming either unit directly over USB.
613 You may wish to begin by ensuring you have current firmware images.
614 These are distributed as part of the AltOS software bundle that
615 also includes the AltosUI ground station program. Newer ground
616 station versions typically work fine with older firmware versions,
617 so you don't need to update your devices just to try out new
618 software features. You can always download the most recent
619 version from <a class="ulink" href="http://www.altusmetrum.org/AltOS/" target="_top">http://www.altusmetrum.org/AltOS/</a>.
621 We recommend updating TeleMetrum first, before updating TeleDongle.
622 </p><div class="section" title="Updating TeleMetrum Firmware"><div class="titlepage"><div><div><h3 class="title"><a name="id2554717"></a>Updating TeleMetrum Firmware</h3></div></div></div><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
623 Find the 'programming cable' that you got as part of the starter
624 kit, that has a red 8-pin MicroMaTch connector on one end and a
625 red 4-pin MicroMaTch connector on the other end.
626 </li><li class="listitem">
627 Take the 2 screws out of the TeleDongle case to get access
628 to the circuit board.
629 </li><li class="listitem">
630 Plug the 8-pin end of the programming cable to the
631 matching connector on the TeleDongle, and the 4-pin end to the
632 matching connector on the TeleMetrum.
633 Note that each MicroMaTch connector has an alignment pin that
634 goes through a hole in the PC board when you have the cable
636 </li><li class="listitem">
637 Attach a battery to the TeleMetrum board.
638 </li><li class="listitem">
639 Plug the TeleDongle into your computer's USB port, and power
641 </li><li class="listitem">
642 Run AltosUI, and select 'Flash Image' from the File menu.
643 </li><li class="listitem">
644 Pick the TeleDongle device from the list, identifying it as the
646 </li><li class="listitem">
647 Select the image you want put on the TeleMetrum, which should have a
648 name in the form telemetrum-v1.0-0.7.1.ihx. It should be visible
649 in the default directory, if not you may have to poke around
650 your system to find it.
651 </li><li class="listitem">
652 Make sure the configuration parameters are reasonable
653 looking. If the serial number and/or RF configuration
654 values aren't right, you'll need to change them.
655 </li><li class="listitem">
656 Hit the 'OK' button and the software should proceed to flash
657 the TeleMetrum with new firmware, showing a progress bar.
658 </li><li class="listitem">
659 Confirm that the TeleMetrum board seems to have updated ok, which you
660 can do by plugging in to it over USB and using a terminal program
661 to connect to the board and issue the 'v' command to check
663 </li><li class="listitem">
664 If something goes wrong, give it another try.
665 </li></ol></div></div><div class="section" title="Updating TeleDongle Firmware"><div class="titlepage"><div><div><h3 class="title"><a name="id2564109"></a>Updating TeleDongle Firmware</h3></div></div></div><p>
666 Updating TeleDongle's firmware is just like updating TeleMetrum
667 firmware, but you switch which board is the programmer and which
668 is the programming target.
669 </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
670 Find the 'programming cable' that you got as part of the starter
671 kit, that has a red 8-pin MicroMaTch connector on one end and a
672 red 4-pin MicroMaTch connector on the other end.
673 </li><li class="listitem">
674 Find the USB cable that you got as part of the starter kit, and
675 plug the "mini" end in to the mating connector on TeleMetrum.
676 </li><li class="listitem">
677 Take the 2 screws out of the TeleDongle case to get access
678 to the circuit board.
679 </li><li class="listitem">
680 Plug the 8-pin end of the programming cable to the (latching)
681 matching connector on the TeleMetrum, and the 4-pin end to the
682 matching connector on the TeleDongle.
683 Note that each MicroMaTch connector has an alignment pin that
684 goes through a hole in the PC board when you have the cable
686 </li><li class="listitem">
687 Attach a battery to the TeleMetrum board.
688 </li><li class="listitem">
689 Plug both TeleMetrum and TeleDongle into your computer's USB
690 ports, and power up the TeleMetrum.
691 </li><li class="listitem">
692 Run AltosUI, and select 'Flash Image' from the File menu.
693 </li><li class="listitem">
694 Pick the TeleMetrum device from the list, identifying it as the
696 </li><li class="listitem">
697 Select the image you want put on the TeleDongle, which should have a
698 name in the form teledongle-v0.2-0.7.1.ihx. It should be visible
699 in the default directory, if not you may have to poke around
700 your system to find it.
701 </li><li class="listitem">
702 Make sure the configuration parameters are reasonable
703 looking. If the serial number and/or RF configuration
704 values aren't right, you'll need to change them. The TeleDongle
705 serial number is on the "bottom" of the circuit board, and can
706 usually be read through the translucent blue plastic case without
707 needing to remove the board from the case.
708 </li><li class="listitem">
709 Hit the 'OK' button and the software should proceed to flash
710 the TeleDongle with new firmware, showing a progress bar.
711 </li><li class="listitem">
712 Confirm that the TeleDongle board seems to have updated ok, which you
713 can do by plugging in to it over USB and using a terminal program
714 to connect to the board and issue the 'v' command to check
715 the version, etc. Once you're happy, remove the programming cable
716 and put the cover back on the TeleDongle.
717 </li><li class="listitem">
718 If something goes wrong, give it another try.
720 Be careful removing the programming cable from the locking 8-pin
721 connector on TeleMetrum. You'll need a fingernail or perhaps a thin
722 screwdriver or knife blade to gently pry the locking ears out
723 slightly to extract the connector. We used a locking connector on
724 TeleMetrum to help ensure that the cabling to companion boards
725 used in a rocket don't ever come loose accidentally in flight.
726 </p></div></div></div><div class="chapter" title="Chapter 7. AltosUI"><div class="titlepage"><div><div><h2 class="title"><a name="id2562062"></a>Chapter 7. AltosUI</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="section"><a href="#id2578432">Packet Command Mode</a></span></dt><dt><span class="section"><a href="#id2572301">Monitor Flight</a></span></dt><dd><dl><dt><span class="section"><a href="#id2554918">Launch Pad</a></span></dt><dt><span class="section"><a href="#id2574995">Ascent</a></span></dt><dt><span class="section"><a href="#id2576209">Descent</a></span></dt><dt><span class="section"><a href="#id2561512">Landed</a></span></dt><dt><span class="section"><a href="#id2587026">Site Map</a></span></dt></dl></dd><dt><span class="section"><a href="#id2576446">Save Flight Data</a></span></dt><dt><span class="section"><a href="#id2586529">Replay Flight</a></span></dt><dt><span class="section"><a href="#id2573351">Graph Data</a></span></dt><dt><span class="section"><a href="#id2568352">Export Data</a></span></dt><dd><dl><dt><span class="section"><a href="#id2575553">Comma Separated Value Format</a></span></dt><dt><span class="section"><a href="#id2579115">Keyhole Markup Language (for Google Earth)</a></span></dt></dl></dd><dt><span class="section"><a href="#id2570375">Configure TeleMetrum</a></span></dt><dd><dl><dt><span class="section"><a href="#id2559233">Main Deploy Altitude</a></span></dt><dt><span class="section"><a href="#id2552914">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2582365">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2563940">Radio Calibration</a></span></dt><dt><span class="section"><a href="#id2561819">Callsign</a></span></dt><dt><span class="section"><a href="#id2572471">Maximum Flight Log Size</a></span></dt></dl></dd><dt><span class="section"><a href="#id2564177">Configure AltosUI</a></span></dt><dd><dl><dt><span class="section"><a href="#id2575461">Voice Settings</a></span></dt><dt><span class="section"><a href="#id2573515">Log Directory</a></span></dt><dt><span class="section"><a href="#id2565097">Callsign</a></span></dt><dt><span class="section"><a href="#id2546395">Serial Debug</a></span></dt></dl></dd><dt><span class="section"><a href="#id2575721">Flash Image</a></span></dt><dt><span class="section"><a href="#id2576287">Fire Igniter</a></span></dt></dl></div><p>
727 The AltosUI program provides a graphical user interface for
728 interacting with the Altus Metrum product family, including
729 TeleMetrum and TeleDongle. AltosUI can monitor telemetry data,
730 configure TeleMetrum and TeleDongle devices and many other
731 tasks. The primary interface window provides a selection of
732 buttons, one for each major activity in the system. This manual
733 is split into chapters, each of which documents one of the tasks
734 provided from the top-level toolbar.
735 </p><div class="section" title="Packet Command Mode"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2578432"></a>Packet Command Mode</h2></div><div><h3 class="subtitle">Controlling TeleMetrum Over The Radio Link</h3></div></div></div><p>
736 One of the unique features of the Altus Metrum environment is
737 the ability to create a two way command link between TeleDongle
738 and TeleMetrum using the digital radio transceivers built into
739 each device. This allows you to interact with TeleMetrum from
740 afar, as if it were directly connected to the computer.
742 Any operation which can be performed with TeleMetrum
743 can either be done with TeleMetrum directly connected to
744 the computer via the USB cable, or through the packet
745 link. Simply select the appropriate TeleDongle device when
746 the list of devices is presented and AltosUI will use packet
749 One oddity in the current interface is how AltosUI selects the
750 channel for packet mode communications. Instead of providing
751 an interface to specifically configure the channel, it uses
752 whatever channel was most recently selected for the target
753 TeleDongle device in Monitor Flight mode. If you haven't ever
754 used that mode with the TeleDongle in question, select the
755 Monitor Flight button from the top level UI, pick the
756 appropriate TeleDongle device. Once the flight monitoring
757 window is open, select the desired channel and then close it
758 down again. All Packet Command Mode operations will now use
760 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
761 Save Flight Data—Recover flight data from the rocket without
763 </p></li><li class="listitem"><p>
764 Configure TeleMetrum—Reset apogee delays or main deploy
765 heights to respond to changing launch conditions. You can
766 also 'reboot' the TeleMetrum device. Use this to remotely
767 enable the flight computer by turning TeleMetrum on while
768 horizontal, then once the airframe is oriented for launch,
769 you can reboot TeleMetrum and have it restart in pad mode
770 without having to climb the scary ladder.
771 </p></li><li class="listitem"><p>
772 Fire Igniters—Test your deployment charges without snaking
773 wires out through holes in the airframe. Simply assembly the
774 rocket as if for flight with the apogee and main charges
775 loaded, then remotely command TeleMetrum to fire the
777 </p></li></ul></div><p>
778 Packet command mode uses the same RF channels as telemetry
779 mode. Configure the desired TeleDongle channel using the
780 flight monitor window channel selector and then close that
781 window before performing the desired operation.
783 TeleMetrum only enables packet command mode in 'idle' mode, so
784 make sure you have TeleMetrum lying horizontally when you turn
785 it on. Otherwise, TeleMetrum will start in 'pad' mode ready for
786 flight and will not be listening for command packets from TeleDongle.
788 When packet command mode is enabled, you can monitor the link
789 by watching the lights on the TeleDongle and TeleMetrum
790 devices. The red LED will flash each time TeleDongle or
791 TeleMetrum transmit a packet while the green LED will light up
792 on TeleDongle while it is waiting to receive a packet from
794 </p></div><div class="section" title="Monitor Flight"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2572301"></a>Monitor Flight</h2></div><div><h3 class="subtitle">Receive, Record and Display Telemetry Data</h3></div></div></div><p>
795 Selecting this item brings up a dialog box listing all of the
796 connected TeleDongle devices. When you choose one of these,
797 AltosUI will create a window to display telemetry data as
798 received by the selected TeleDongle device.
800 All telemetry data received are automatically recorded in
801 suitable log files. The name of the files includes the current
802 date and rocket serial and flight numbers.
804 The radio channel being monitored by the TeleDongle device is
805 displayed at the top of the window. You can configure the
806 channel by clicking on the channel box and selecting the desired
807 channel. AltosUI remembers the last channel selected for each
808 TeleDongle and selects that automatically the next time you use
811 Below the TeleDongle channel selector, the window contains a few
812 significant pieces of information about the TeleMetrum providing
813 the telemetry data stream:
814 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>The TeleMetrum callsign</p></li><li class="listitem"><p>The TeleMetrum serial number</p></li><li class="listitem"><p>The flight number. Each TeleMetrum remembers how many
816 </p></li><li class="listitem"><p>
817 The rocket flight state. Each flight passes through several
818 states including Pad, Boost, Fast, Coast, Drogue, Main and
820 </p></li><li class="listitem"><p>
821 The Received Signal Strength Indicator value. This lets
822 you know how strong a signal TeleDongle is receiving. The
823 radio inside TeleDongle operates down to about -99dBm;
824 weaker signals may not be receiveable. The packet link uses
825 error correction and detection techniques which prevent
826 incorrect data from being reported.
827 </p></li></ul></div><p>
828 Finally, the largest portion of the window contains a set of
829 tabs, each of which contain some information about the rocket.
830 They're arranged in 'flight order' so that as the flight
831 progresses, the selected tab automatically switches to display
832 data relevant to the current state of the flight. You can select
833 other tabs at any time. The final 'table' tab contains all of
834 the telemetry data in one place.
835 </p><div class="section" title="Launch Pad"><div class="titlepage"><div><div><h3 class="title"><a name="id2554918"></a>Launch Pad</h3></div></div></div><p>
836 The 'Launch Pad' tab shows information used to decide when the
837 rocket is ready for flight. The first elements include red/green
838 indicators, if any of these is red, you'll want to evaluate
839 whether the rocket is ready to launch:
840 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
841 Battery Voltage. This indicates whether the LiPo battery
842 powering the TeleMetrum has sufficient charge to last for
843 the duration of the flight. A value of more than
844 3.7V is required for a 'GO' status.
845 </p></li><li class="listitem"><p>
846 Apogee Igniter Voltage. This indicates whether the apogee
847 igniter has continuity. If the igniter has a low
848 resistance, then the voltage measured here will be close
849 to the LiPo battery voltage. A value greater than 3.2V is
850 required for a 'GO' status.
851 </p></li><li class="listitem"><p>
852 Main Igniter Voltage. This indicates whether the main
853 igniter has continuity. If the igniter has a low
854 resistance, then the voltage measured here will be close
855 to the LiPo battery voltage. A value greater than 3.2V is
856 required for a 'GO' status.
857 </p></li><li class="listitem"><p>
858 GPS Locked. This indicates whether the GPS receiver is
859 currently able to compute position information. GPS requires
860 at least 4 satellites to compute an accurate position.
861 </p></li><li class="listitem"><p>
862 GPS Ready. This indicates whether GPS has reported at least
863 10 consecutive positions without losing lock. This ensures
864 that the GPS receiver has reliable reception from the
866 </p></li></ul></div><p>
868 The LaunchPad tab also shows the computed launch pad position
869 and altitude, averaging many reported positions to improve the
872 </p></div><div class="section" title="Ascent"><div class="titlepage"><div><div><h3 class="title"><a name="id2574995"></a>Ascent</h3></div></div></div><p>
873 This tab is shown during Boost, Fast and Coast
874 phases. The information displayed here helps monitor the
875 rocket as it heads towards apogee.
877 The height, speed and acceleration are shown along with the
878 maxium values for each of them. This allows you to quickly
879 answer the most commonly asked questions you'll hear during
882 The current latitude and longitude reported by the GPS are
883 also shown. Note that under high acceleration, these values
884 may not get updated as the GPS receiver loses position
885 fix. Once the rocket starts coasting, the receiver should
886 start reporting position again.
888 Finally, the current igniter voltages are reported as in the
889 Launch Pad tab. This can help diagnose deployment failures
890 caused by wiring which comes loose under high acceleration.
891 </p></div><div class="section" title="Descent"><div class="titlepage"><div><div><h3 class="title"><a name="id2576209"></a>Descent</h3></div></div></div><p>
892 Once the rocket has reached apogee and (we hope) activated the
893 apogee charge, attention switches to tracking the rocket on
894 the way back to the ground, and for dual-deploy flights,
895 waiting for the main charge to fire.
897 To monitor whether the apogee charge operated correctly, the
898 current descent rate is reported along with the current
899 height. Good descent rates generally range from 15-30m/s.
901 To help locate the rocket in the sky, use the elevation and
902 bearing information to figure out where to look. Elevation is
903 in degrees above the horizon. Bearing is reported in degrees
904 relative to true north. Range can help figure out how big the
905 rocket will appear. Note that all of these values are relative
906 to the pad location. If the elevation is near 90°, the rocket
907 is over the pad, not over you.
909 Finally, the igniter voltages are reported in this tab as
910 well, both to monitor the main charge as well as to see what
911 the status of the apogee charge is.
912 </p></div><div class="section" title="Landed"><div class="titlepage"><div><div><h3 class="title"><a name="id2561512"></a>Landed</h3></div></div></div><p>
913 Once the rocket is on the ground, attention switches to
914 recovery. While the radio signal is generally lost once the
915 rocket is on the ground, the last reported GPS position is
916 generally within a short distance of the actual landing location.
918 The last reported GPS position is reported both by
919 latitude and longitude as well as a bearing and distance from
920 the launch pad. The distance should give you a good idea of
921 whether you'll want to walk or hitch a ride. Take the reported
922 latitude and longitude and enter them into your handheld GPS
923 unit and have that compute a track to the landing location.
925 Finally, the maximum height, speed and acceleration reported
926 during the flight are displayed for your admiring observers.
927 </p></div><div class="section" title="Site Map"><div class="titlepage"><div><div><h3 class="title"><a name="id2587026"></a>Site Map</h3></div></div></div><p>
928 When the rocket gets a GPS fix, the Site Map tab will map
929 the rocket's position to make it easier for you to locate the
930 rocket, both while it is in the air, and when it has landed. The
931 rocket's state is indicated by colour: white for pad, red for
932 boost, pink for fast, yellow for coast, light blue for drogue,
933 dark blue for main, and black for landed.
935 The map's scale is approximately 3m (10ft) per pixel. The map
936 can be dragged using the left mouse button. The map will attempt
937 to keep the rocket roughly centred while data is being received.
939 Images are fetched automatically via the Google Maps Static API,
940 and are cached for reuse. If map images cannot be downloaded,
941 the rocket's path will be traced on a dark grey background
943 </p></div></div><div class="section" title="Save Flight Data"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2576446"></a>Save Flight Data</h2></div></div></div><p>
944 TeleMetrum records flight data to its internal flash memory.
945 This data is recorded at a much higher rate than the telemetry
946 system can handle, and is not subject to radio drop-outs. As
947 such, it provides a more complete and precise record of the
948 flight. The 'Save Flight Data' button allows you to read the
949 flash memory and write it to disk.
951 Clicking on the 'Save Flight Data' button brings up a list of
952 connected TeleMetrum and TeleDongle devices. If you select a
953 TeleMetrum device, the flight data will be downloaded from that
954 device directly. If you select a TeleDongle device, flight data
955 will be downloaded from a TeleMetrum device connected via the
956 packet command link to the specified TeleDongle. See the chapter
957 on Packet Command Mode for more information about this.
959 After the device has been selected, a dialog showing the
960 flight data saved in the device will be shown allowing you to
961 select which flights to download and which to delete. With
962 version 0.9 or newer firmware, you must erase flights in order
963 for the space they consume to be reused by another
964 flight. This prevents you from accidentally losing flight data
965 if you neglect to download data before flying again. Note that
966 if there is no more space available in the device, then no
967 data will be recorded for a flight.
969 The filename for each flight log is computed automatically
970 from the recorded flight date, TeleMetrum serial number and
971 flight number information.
972 </p></div><div class="section" title="Replay Flight"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2586529"></a>Replay Flight</h2></div></div></div><p>
973 Select this button and you are prompted to select a flight
974 record file, either a .telem file recording telemetry data or a
975 .eeprom file containing flight data saved from the TeleMetrum
978 Once a flight record is selected, the flight monitor interface
979 is displayed and the flight is re-enacted in real time. Check
980 the Monitor Flight chapter above to learn how this window operates.
981 </p></div><div class="section" title="Graph Data"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2573351"></a>Graph Data</h2></div></div></div><p>
982 Select this button and you are prompted to select a flight
983 record file, either a .telem file recording telemetry data or a
984 .eeprom file containing flight data saved from the TeleMetrum
987 Once a flight record is selected, the acceleration (blue),
988 velocity (green) and altitude (red) of the flight are plotted and
989 displayed, measured in metric units.
991 The graph can be zoomed into a particular area by clicking and
992 dragging down and to the right. Once zoomed, the graph can be
993 reset by clicking and dragging up and to the left. Holding down
994 control and clicking and dragging allows the graph to be panned.
995 The right mouse button causes a popup menu to be displayed, giving
996 you the option save or print the plot.
998 Note that telemetry files will generally produce poor graphs
999 due to the lower sampling rate and missed telemetry packets,
1000 and will also often have significant amounts of data received
1001 while the rocket was waiting on the pad. Use saved flight data
1002 for graphing where possible.
1003 </p></div><div class="section" title="Export Data"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2568352"></a>Export Data</h2></div></div></div><p>
1004 This tool takes the raw data files and makes them available for
1005 external analysis. When you select this button, you are prompted to select a flight
1006 data file (either .eeprom or .telem will do, remember that
1007 .eeprom files contain higher resolution and more continuous
1008 data). Next, a second dialog appears which is used to select
1009 where to write the resulting file. It has a selector to choose
1010 between CSV and KML file formats.
1011 </p><div class="section" title="Comma Separated Value Format"><div class="titlepage"><div><div><h3 class="title"><a name="id2575553"></a>Comma Separated Value Format</h3></div></div></div><p>
1012 This is a text file containing the data in a form suitable for
1013 import into a spreadsheet or other external data analysis
1014 tool. The first few lines of the file contain the version and
1015 configuration information from the TeleMetrum device, then
1016 there is a single header line which labels all of the
1017 fields. All of these lines start with a '#' character which
1018 most tools can be configured to skip over.
1020 The remaining lines of the file contain the data, with each
1021 field separated by a comma and at least one space. All of
1022 the sensor values are converted to standard units, with the
1023 barometric data reported in both pressure, altitude and
1024 height above pad units.
1025 </p></div><div class="section" title="Keyhole Markup Language (for Google Earth)"><div class="titlepage"><div><div><h3 class="title"><a name="id2579115"></a>Keyhole Markup Language (for Google Earth)</h3></div></div></div><p>
1026 This is the format used by
1027 Googleearth to provide an overlay within that
1028 application. With this, you can use Googleearth to see the
1029 whole flight path in 3D.
1030 </p></div></div><div class="section" title="Configure TeleMetrum"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2570375"></a>Configure TeleMetrum</h2></div></div></div><p>
1031 Select this button and then select either a TeleMetrum or
1032 TeleDongle Device from the list provided. Selecting a TeleDongle
1033 device will use Packet Comamnd Mode to configure remote
1034 TeleMetrum device. Learn how to use this in the Packet Command
1037 The first few lines of the dialog provide information about the
1038 connected TeleMetrum device, including the product name,
1039 software version and hardware serial number. Below that are the
1040 individual configuration entries.
1042 At the bottom of the dialog, there are four buttons:
1043 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
1044 Save. This writes any changes to the TeleMetrum
1045 configuration parameter block in flash memory. If you don't
1046 press this button, any changes you make will be lost.
1047 </p></li><li class="listitem"><p>
1048 Reset. This resets the dialog to the most recently saved values,
1049 erasing any changes you have made.
1050 </p></li><li class="listitem"><p>
1051 Reboot. This reboots the TeleMetrum device. Use this to
1052 switch from idle to pad mode by rebooting once the rocket is
1053 oriented for flight.
1054 </p></li><li class="listitem"><p>
1055 Close. This closes the dialog. Any unsaved changes will be
1057 </p></li></ul></div><p>
1058 The rest of the dialog contains the parameters to be configured.
1059 </p><div class="section" title="Main Deploy Altitude"><div class="titlepage"><div><div><h3 class="title"><a name="id2559233"></a>Main Deploy Altitude</h3></div></div></div><p>
1060 This sets the altitude (above the recorded pad altitude) at
1061 which the 'main' igniter will fire. The drop-down menu shows
1062 some common values, but you can edit the text directly and
1063 choose whatever you like. If the apogee charge fires below
1064 this altitude, then the main charge will fire two seconds
1065 after the apogee charge fires.
1066 </p></div><div class="section" title="Apogee Delay"><div class="titlepage"><div><div><h3 class="title"><a name="id2552914"></a>Apogee Delay</h3></div></div></div><p>
1067 When flying redundant electronics, it's often important to
1068 ensure that multiple apogee charges don't fire at precisely
1069 the same time as that can overpressurize the apogee deployment
1070 bay and cause a structural failure of the airframe. The Apogee
1071 Delay parameter tells the flight computer to fire the apogee
1072 charge a certain number of seconds after apogee has been
1074 </p></div><div class="section" title="Radio Channel"><div class="titlepage"><div><div><h3 class="title"><a name="id2582365"></a>Radio Channel</h3></div></div></div><p>
1075 This configures which of the 10 radio channels to use for both
1076 telemetry and packet command mode. Note that if you set this
1077 value via packet command mode, you will have to reconfigure
1078 the TeleDongle channel before you will be able to use packet
1080 </p></div><div class="section" title="Radio Calibration"><div class="titlepage"><div><div><h3 class="title"><a name="id2563940"></a>Radio Calibration</h3></div></div></div><p>
1081 The radios in every Altus Metrum device are calibrated at the
1082 factory to ensure that they transmit and receive on the
1083 specified frequency for each channel. You can adjust that
1084 calibration by changing this value. To change the TeleDongle's
1085 calibration, you must reprogram the unit completely.
1086 </p></div><div class="section" title="Callsign"><div class="titlepage"><div><div><h3 class="title"><a name="id2561819"></a>Callsign</h3></div></div></div><p>
1087 This sets the callsign included in each telemetry packet. Set this
1088 as needed to conform to your local radio regulations.
1089 </p></div><div class="section" title="Maximum Flight Log Size"><div class="titlepage"><div><div><h3 class="title"><a name="id2572471"></a>Maximum Flight Log Size</h3></div></div></div><p>
1090 This sets the space (in kilobytes) allocated for each flight
1091 log. The available space will be divided into chunks of this
1092 size. A smaller value will allow more flights to be stored,
1093 a larger value will record data from longer flights.
1095 During ascent, TeleMetrum records barometer and
1096 accelerometer values 100 times per second, other analog
1097 information (voltages and temperature) 6 times per second
1098 and GPS data once per second. During descent, the non-GPS
1099 data is recorded 1/10th as often. Each barometer +
1100 accelerometer record takes 8 bytes.
1102 The default, 192kB, will store over 200 seconds of data at
1103 the ascent rate, or over 2000 seconds of data at the descent
1104 rate. That's plenty for most flights. This leaves enough
1105 storage for five flights in a 1MB system, or 10 flights in a
1108 The configuration block takes the last available block of
1109 memory, on v1.0 boards that's just 256 bytes. However, the
1110 flash part on the v1.1 boards uses 64kB for each block.
1111 </p></div></div><div class="section" title="Configure AltosUI"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2564177"></a>Configure AltosUI</h2></div></div></div><p>
1112 This button presents a dialog so that you can configure the AltosUI global settings.
1113 </p><div class="section" title="Voice Settings"><div class="titlepage"><div><div><h3 class="title"><a name="id2575461"></a>Voice Settings</h3></div></div></div><p>
1114 AltosUI provides voice annoucements during flight so that you
1115 can keep your eyes on the sky and still get information about
1116 the current flight status. However, sometimes you don't want
1118 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>Enable—turns all voice announcements on and off</p></li><li class="listitem"><p>
1119 Test Voice—Plays a short message allowing you to verify
1120 that the audio systme is working and the volume settings
1122 </p></li></ul></div></div><div class="section" title="Log Directory"><div class="titlepage"><div><div><h3 class="title"><a name="id2573515"></a>Log Directory</h3></div></div></div><p>
1123 AltosUI logs all telemetry data and saves all TeleMetrum flash
1124 data to this directory. This directory is also used as the
1125 staring point when selecting data files for display or export.
1127 Click on the directory name to bring up a directory choosing
1128 dialog, select a new directory and click 'Select Directory' to
1129 change where AltosUI reads and writes data files.
1130 </p></div><div class="section" title="Callsign"><div class="titlepage"><div><div><h3 class="title"><a name="id2565097"></a>Callsign</h3></div></div></div><p>
1131 This value is used in command packet mode and is transmitted
1132 in each packet sent from TeleDongle and received from
1133 TeleMetrum. It is not used in telemetry mode as that transmits
1134 packets only from TeleMetrum to TeleDongle. Configure this
1135 with the AltosUI operators callsign as needed to comply with
1136 your local radio regulations.
1137 </p></div><div class="section" title="Serial Debug"><div class="titlepage"><div><div><h3 class="title"><a name="id2546395"></a>Serial Debug</h3></div></div></div><p>
1138 This causes all communication with a connected device to be
1139 dumped to the console from which AltosUI was started. If
1140 you've started it from an icon or menu entry, the output
1141 will simply be discarded. This mode can be useful to debug
1142 various serial communication issues.
1143 </p></div></div><div class="section" title="Flash Image"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2575721"></a>Flash Image</h2></div></div></div><p>
1144 This reprograms any Altus Metrum device by using a TeleMetrum or
1145 TeleDongle as a programming dongle. Please read the directions
1146 for connecting the programming cable in the main TeleMetrum
1147 manual before reading these instructions.
1149 Once you have the programmer and target devices connected,
1150 push the 'Flash Image' button. That will present a dialog box
1151 listing all of the connected devices. Carefully select the
1152 programmer device, not the device to be programmed.
1154 Next, select the image to flash to the device. These are named
1155 with the product name and firmware version. The file selector
1156 will start in the directory containing the firmware included
1157 with the AltosUI package. Navigate to the directory containing
1158 the desired firmware if it isn't there.
1160 Next, a small dialog containing the device serial number and
1161 RF calibration values should appear. If these values are
1162 incorrect (possibly due to a corrupted image in the device),
1163 enter the correct values here.
1165 Finally, a dialog containing a progress bar will follow the
1166 programming process.
1168 When programming is complete, the target device will
1169 reboot. Note that if the target device is connected via USB, you
1170 will have to unplug it and then plug it back in for the USB
1171 connection to reset so that you can communicate with the device
1173 </p></div><div class="section" title="Fire Igniter"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2576287"></a>Fire Igniter</h2></div></div></div><p>
1174 This activates the igniter circuits in TeleMetrum to help test
1175 recovery systems deployment. Because this command can operate
1176 over the Packet Command Link, you can prepare the rocket as
1177 for flight and then test the recovery system without needing
1178 to snake wires inside the airframe.
1180 Selecting the 'Fire Igniter' button brings up the usual device
1181 selection dialog. Pick the desired TeleDongle or TeleMetrum
1182 device. This brings up another window which shows the current
1183 continutity test status for both apogee and main charges.
1185 Next, select the desired igniter to fire. This will enable the
1188 Select the 'Arm' button. This enables the 'Fire' button. The
1189 word 'Arm' is replaced by a countdown timer indicating that
1190 you have 10 seconds to press the 'Fire' button or the system
1191 will deactivate, at which point you start over again at
1192 selecting the desired igniter.
1193 </p></div></div><div class="chapter" title="Chapter 8. Using Altus Metrum Products"><div class="titlepage"><div><div><h2 class="title"><a name="id2570538"></a>Chapter 8. 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="#id2576134">Being Legal</a></span></dt><dt><span class="section"><a href="#id2573850">In the Rocket</a></span></dt><dt><span class="section"><a href="#id2572694">On the Ground</a></span></dt><dt><span class="section"><a href="#id2579324">Data Analysis</a></span></dt><dt><span class="section"><a href="#id2585899">Future Plans</a></span></dt></dl></div><div class="section" title="Being Legal"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2576134"></a>Being Legal</h2></div></div></div><p>
1194 First off, in the US, you need an <a class="ulink" href="http://www.altusmetrum.org/Radio/" target="_top">amateur radio license</a> or
1195 other authorization to legally operate the radio transmitters that are part
1197 </p></div><div class="section" title="In the Rocket"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2573850"></a>In the Rocket</h2></div></div></div><p>
1198 In the rocket itself, you just need a <a class="ulink" href="http://www.altusmetrum.org/TeleMetrum/" target="_top">TeleMetrum</a> board and
1199 a LiPo rechargeable battery. An 860mAh battery weighs less than a 9V
1200 alkaline battery, and will run a <a class="ulink" href="http://www.altusmetrum.org/TeleMetrum/" target="_top">TeleMetrum</a> for hours.
1202 By default, we ship TeleMetrum with a simple wire antenna. If your
1203 electronics bay or the airframe it resides within is made of carbon fiber,
1204 which is opaque to RF signals, you may choose to have an SMA connector
1205 installed so that you can run a coaxial cable to an antenna mounted
1206 elsewhere in the rocket.
1207 </p></div><div class="section" title="On the Ground"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2572694"></a>On the Ground</h2></div></div></div><p>
1208 To receive the data stream from the rocket, you need an antenna and short
1209 feedline connected to one of our <a class="ulink" href="http://www.altusmetrum.org/TeleDongle/" target="_top">TeleDongle</a> units. The
1210 TeleDongle in turn plugs directly into the USB port on a notebook
1211 computer. Because TeleDongle looks like a simple serial port, your computer
1212 does not require special device drivers... just plug it in.
1214 The GUI tool, AltosUI, is written in Java and runs across
1215 Linux, Mac OS and Windows. There's also a suite of C tools
1216 for Linux which can perform most of the same tasks.
1218 After the flight, you can use the RF link to extract the more detailed data
1219 logged in the rocket, or you can use a mini USB cable to plug into the
1220 TeleMetrum board directly. Pulling out the data without having to open up
1221 the rocket is pretty cool! A USB cable is also how you charge the LiPo
1222 battery, so you'll want one of those anyway... the same cable used by lots
1223 of digital cameras and other modern electronic stuff will work fine.
1225 If your rocket lands out of sight, you may enjoy having a hand-held GPS
1226 receiver, so that you can put in a waypoint for the last reported rocket
1227 position before touch-down. This makes looking for your rocket a lot like
1228 Geo-Cacheing... just go to the waypoint and look around starting from there.
1230 You may also enjoy having a ham radio "HT" that covers the 70cm band... you
1231 can use that with your antenna to direction-find the rocket on the ground
1232 the same way you can use a Walston or Beeline tracker. This can be handy
1233 if the rocket is hiding in sage brush or a tree, or if the last GPS position
1234 doesn't get you close enough because the rocket dropped into a canyon, or
1235 the wind is blowing it across a dry lake bed, or something like that... Keith
1236 and Bdale both currently own and use the Yaesu VX-7R at launches.
1238 So, to recap, on the ground the hardware you'll need includes:
1239 </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
1240 an antenna and feedline
1241 </li><li class="listitem">
1243 </li><li class="listitem">
1245 </li><li class="listitem">
1246 optionally, a handheld GPS receiver
1247 </li><li class="listitem">
1248 optionally, an HT or receiver covering 435 Mhz
1251 The best hand-held commercial directional antennas we've found for radio
1252 direction finding rockets are from
1253 <a class="ulink" href="http://www.arrowantennas.com/" target="_top">
1256 The 440-3 and 440-5 are both good choices for finding a
1257 TeleMetrum-equipped rocket when used with a suitable 70cm HT.
1258 </p></div><div class="section" title="Data Analysis"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2579324"></a>Data Analysis</h2></div></div></div><p>
1259 Our software makes it easy to log the data from each flight, both the
1260 telemetry received over the RF link during the flight itself, and the more
1261 complete data log recorded in the DataFlash memory on the TeleMetrum
1262 board. Once this data is on your computer, our postflight tools make it
1263 easy to quickly get to the numbers everyone wants, like apogee altitude,
1264 max acceleration, and max velocity. You can also generate and view a
1265 standard set of plots showing the altitude, acceleration, and
1266 velocity of the rocket during flight. And you can even export a data file
1267 useable with Google Maps and Google Earth for visualizing the flight path
1268 in two or three dimensions!
1270 Our ultimate goal is to emit a set of files for each flight that can be
1271 published as a web page per flight, or just viewed on your local disk with
1273 </p></div><div class="section" title="Future Plans"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2585899"></a>Future Plans</h2></div></div></div><p>
1274 In the future, we intend to offer "companion boards" for the rocket that will
1275 plug in to TeleMetrum to collect additional data, provide more pyro channels,
1276 and so forth. A reference design for a companion board will be documented
1277 soon, and will be compatible with open source Arduino programming tools.
1279 We are also working on the design of a hand-held ground terminal that will
1280 allow monitoring the rocket's status, collecting data during flight, and
1281 logging data after flight without the need for a notebook computer on the
1282 flight line. Particularly since it is so difficult to read most notebook
1283 screens in direct sunlight, we think this will be a great thing to have.
1285 Because all of our work is open, both the hardware designs and the software,
1286 if you have some great idea for an addition to the current Altus Metrum family,
1287 feel free to dive in and help! Or let us know what you'd like to see that
1288 we aren't already working on, and maybe we'll get excited about it too...
1289 </p></div></div></div></body></html>
projects / web / altusmetrum / blob