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="id2291362"></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 © 2010 Bdale Garbee and Keith Packard</p></div><div><div class="legalnotice" title="Legal Notice"><a name="id2566861"></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 0.8</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="id2558408"></a>Acknowledgements</h2></div></div></div>
9 Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing "The
10 Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter
11 Kit" which has turned into the Getting Started chapter in this
12 book. Bob was one of our first customers for a production
13 TeleMetrum, and the enthusiasm that led to his contribution of
14 this section is immensely gratifying and highy appreciated!
17 And thanks to Anthony (AJ) Towns for contributing the
18 AltosUI graphing and site map code and documentation. Free
19 software means that our customers and friends can become our
20 collaborators, and we certainly appreciate this level of
24 Have fun using these products, and we hope to meet all of you
25 out on the rocket flight line somewhere.
26 </p><div class="literallayout"><p><br>
27 Bdale Garbee, KB0G<br>
28 NAR #87103, TRA #12201<br>
30 Keith Packard, KD7SQG<br>
31 NAR #88757, TRA #12200<br>
34 </div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="chapter"><a href="#id2562143">1. Introduction and Overview</a></span></dt><dt><span class="chapter"><a href="#id2535919">2. Getting Started</a></span></dt><dd><dl><dt><span class="section"><a href="#id2574950">FAQ</a></span></dt></dl></dd><dt><span class="chapter"><a href="#id2562056">3. Specifications</a></span></dt><dt><span class="chapter"><a href="#id2589910">4. Handling Precautions</a></span></dt><dt><span class="chapter"><a href="#id2562288">5. Hardware Overview</a></span></dt><dt><span class="chapter"><a href="#id2568154">6. System Operation</a></span></dt><dd><dl><dt><span class="section"><a href="#id2571301">Firmware Modes </a></span></dt><dt><span class="section"><a href="#id2573013">GPS </a></span></dt><dt><span class="section"><a href="#id2587417">Ground Testing </a></span></dt><dt><span class="section"><a href="#id2587414">Radio Link </a></span></dt><dt><span class="section"><a href="#id2558135">Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#id2578406">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2569320">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2587127">Main Deployment Altitude</a></span></dt></dl></dd><dt><span class="section"><a href="#id2565755">Calibration</a></span></dt><dd><dl><dt><span class="section"><a href="#id2589478">Radio Frequency</a></span></dt><dt><span class="section"><a href="#id2579588">Accelerometer</a></span></dt></dl></dd><dt><span class="section"><a href="#id2587826">Updating Device Firmware</a></span></dt><dd><dl><dt><span class="section"><a href="#id2560725">Updating TeleMetrum Firmware</a></span></dt><dt><span class="section"><a href="#id2579530">Updating TeleDongle Firmware</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#id2576399">7. AltosUI</a></span></dt><dd><dl><dt><span class="section"><a href="#id2576677">Packet Command Mode</a></span></dt><dt><span class="section"><a href="#id2581723">Monitor Flight</a></span></dt><dd><dl><dt><span class="section"><a href="#id2576742">Launch Pad</a></span></dt><dt><span class="section"><a href="#id2571392">Ascent</a></span></dt><dt><span class="section"><a href="#id2578242">Descent</a></span></dt><dt><span class="section"><a href="#id2586734">Landed</a></span></dt><dt><span class="section"><a href="#id2568067">Site Map</a></span></dt></dl></dd><dt><span class="section"><a href="#id2572352">Save Flight Data</a></span></dt><dt><span class="section"><a href="#id2592536">Replay Flight</a></span></dt><dt><span class="section"><a href="#id2579359">Graph Data</a></span></dt><dt><span class="section"><a href="#id2574359">Export Data</a></span></dt><dd><dl><dt><span class="section"><a href="#id2581561">Comma Separated Value Format</a></span></dt><dt><span class="section"><a href="#id2585122">Keyhole Markup Language (for Google Earth)</a></span></dt></dl></dd><dt><span class="section"><a href="#id2576382">Configure TeleMetrum</a></span></dt><dd><dl><dt><span class="section"><a href="#id2565240">Main Deploy Altitude</a></span></dt><dt><span class="section"><a href="#id2558922">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2588372">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2569947">Radio Calibration</a></span></dt><dt><span class="section"><a href="#id2567826">Callsign</a></span></dt></dl></dd><dt><span class="section"><a href="#id2567986">Configure AltosUI</a></span></dt><dd><dl><dt><span class="section"><a href="#id2554292">Voice Settings</a></span></dt><dt><span class="section"><a href="#id2592599">Log Directory</a></span></dt><dt><span class="section"><a href="#id2559399">Callsign</a></span></dt></dl></dd><dt><span class="section"><a href="#id2579274">Flash Image</a></span></dt><dt><span class="section"><a href="#id2577046">Fire Igniter</a></span></dt></dl></dd><dt><span class="chapter"><a href="#id2587842">8. Using Altus Metrum Products</a></span></dt><dd><dl><dt><span class="section"><a href="#id2574948">Being Legal</a></span></dt><dd><dl><dt><span class="section"><a href="#id2561015">In the Rocket</a></span></dt><dt><span class="section"><a href="#id2575161">On the Ground</a></span></dt><dt><span class="section"><a href="#id2581564">Data Analysis</a></span></dt><dt><span class="section"><a href="#id2562286">Future Plans</a></span></dt></dl></dd></dl></dd></dl></div><div class="chapter" title="Chapter 1. Introduction and Overview"><div class="titlepage"><div><div><h2 class="title"><a name="id2562143"></a>Chapter 1. Introduction and Overview</h2></div></div></div><p>
35 Welcome to the Altus Metrum community! Our circuits and software reflect
36 our passion for both hobby rocketry and Free Software. We hope their
37 capabilities and performance will delight you in every way, but by
38 releasing all of our hardware and software designs under open licenses,
39 we also hope to empower you to take as active a role in our collective
42 The focal point of our community is TeleMetrum, a dual deploy altimeter
43 with fully integrated GPS and radio telemetry as standard features, and
44 a "companion interface" that will support optional capabilities in the
47 Complementing TeleMetrum is TeleDongle, a USB to RF interface for
48 communicating with TeleMetrum. Combined with your choice of antenna and
49 notebook computer, TeleDongle and our associated user interface software
50 form a complete ground station capable of logging and displaying in-flight
51 telemetry, aiding rocket recovery, then processing and archiving flight
52 data for analysis and review.
54 More products will be added to the Altus Metrum family over time, and
55 we currently envision that this will be a single, comprehensive manual
56 for the entire product family.
57 </p></div><div class="chapter" title="Chapter 2. Getting Started"><div class="titlepage"><div><div><h2 class="title"><a name="id2535919"></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="#id2574950">FAQ</a></span></dt></dl></div><p>
58 The first thing to do after you check the inventory of parts in your
59 "starter kit" is to charge the battery by plugging it into the
60 corresponding socket of the TeleMetrum and then using the USB A to
62 cable to plug the Telemetrum into your computer's USB socket. The
63 TeleMetrum circuitry will charge the battery whenever it is plugged
64 in, because the TeleMetrum's on-off switch does NOT control the
65 charging circuitry. When the GPS chip is initially searching for
66 satellites, TeleMetrum will consume more current than it can pull
67 from the usb port, so the battery must be attached in order to get
68 satellite lock. Once GPS is locked, the current consumption goes back
69 down enough to enable charging while
70 running. So it's a good idea to fully charge the battery as your
71 first item of business so there is no issue getting and maintaining
72 satellite lock. The yellow charge indicator led will go out when the
73 battery is nearly full and the charger goes to trickle charge. It
74 can take several hours to fully recharge a deeply discharged battery.
76 The other active device in the starter kit is the TeleDongle USB to
77 RF interface. If you plug it in to your Mac or Linux computer it should
78 "just work", showing up as a serial port device. Windows systems need
79 driver information that is part of the AltOS download to know that the
80 existing USB modem driver will work. If you are using Linux and are
81 having problems, try moving to a fresher kernel (2.6.33 or newer), as
82 the USB serial driver had ugly bugs in some earlier versions.
84 Next you should obtain and install the AltOS utilities. These include
85 the AltosUI ground station program, current firmware images for
86 TeleMetrum and TeleDongle, and a number of standalone utilities that
87 are rarely needed. Pre-built binary packages are available for Debian
88 Linux, Microsoft Windows, and recent MacOSX versions. Full sourcecode
89 and build instructions for some other Linux variants are also available.
90 The latest version may always be downloaded from
91 <a class="ulink" href="http://altusmetrum.org/AltOS" target="_top">http://altusmetrum.org/AltOS</a>.
93 Both Telemetrum and TeleDongle can be directly communicated
94 with using USB ports. The first thing you should try after getting
95 both units plugged into to your computer's usb port(s) is to run
96 'ao-list' from a terminal-window to see what port-device-name each
97 device has been assigned by the operating system.
98 You will need this information to access the devices via their
99 respective on-board firmware and data using other command line
100 programs in the AltOS software suite.
102 To access the device's firmware for configuration you need a terminal
103 program such as you would use to talk to a modem. The software
104 authors prefer using the program 'cu' which comes from the UUCP package
105 on most Unix-like systems such as Linux. An example command line for
106 cu might be 'cu -l /dev/ttyACM0', substituting the correct number
107 indicated from running the
108 ao-list program. Another reasonable terminal program for Linux is
109 'cutecom'. The default 'escape'
110 character used by CU (i.e. the character you use to
111 issue commands to cu itself instead of sending the command as input
112 to the connected device) is a '~'. You will need this for use in
113 only two different ways during normal operations. First is to exit
114 the program by sending a '~.' which is called a 'escape-disconnect'
115 and allows you to close-out from 'cu'. The
116 second use will be outlined later.
118 Both TeleMetrum and TeleDongle share the concept of a two level
119 command set in their firmware.
120 The first layer has several single letter commands. Once
121 you are using 'cu' (or 'cutecom') sending (typing) a '?'
122 returns a full list of these
123 commands. The second level are configuration sub-commands accessed
124 using the 'c' command, for
125 instance typing 'c?' will give you this second level of commands
126 (all of which require the
127 letter 'c' to access). Please note that most configuration options
128 are stored only in DataFlash memory, and only TeleMetrum has this
129 memory to save the various values entered like the channel number
130 and your callsign when powered off. TeleDongle requires that you
131 set these each time you plug it in, which ao-view can help with.
133 Try setting these config ('c' or second level menu) values. A good
134 place to start is by setting your call sign. By default, the boards
135 use 'N0CALL' which is cute, but not exactly legal!
136 Spend a few minutes getting comfortable with the units, their
137 firmware, and 'cu' (or possibly 'cutecom').
138 For instance, try to send
139 (type) a 'c r 2' and verify the channel change by sending a 'c s'.
140 Verify you can connect and disconnect from the units while in your
141 terminal program by sending the escape-disconnect mentioned above.
143 Note that the 'reboot' command, which is very useful on TeleMetrum,
144 will likely just cause problems with the dongle. The *correct* way
145 to reset the dongle is just to unplug and re-plug it.
147 A fun thing to do at the launch site and something you can do while
148 learning how to use these units is to play with the rf-link access
149 of the TeleMetrum from the TeleDongle. Be aware that you *must* create
150 some physical separation between the devices, otherwise the link will
151 not function due to signal overload in the receivers in each device.
153 Now might be a good time to take a break and read the rest of this
154 manual, particularly about the two "modes" that the TeleMetrum
155 can be placed in and how the position of the TeleMetrum when booting
156 up will determine whether the unit is in "pad" or "idle" mode.
158 You can access a TeleMetrum in idle mode from the Teledongle's USB
159 connection using the rf link
160 by issuing a 'p' command to the TeleDongle. Practice connecting and
161 disconnecting ('~~' while using 'cu') from the TeleMetrum. If
162 you cannot escape out of the "p" command, (by using a '~~' when in
163 CU) then it is likely that your kernel has issues. Try a newer version.
165 Using this rf link allows you to configure the TeleMetrum, test
166 fire e-matches and igniters from the flight line, check pyro-match
167 continuity and so forth. You can leave the unit turned on while it
168 is in 'idle mode' and then place the
169 rocket vertically on the launch pad, walk away and then issue a
170 reboot command. The TeleMetrum will reboot and start sending data
171 having changed to the "pad" mode. If the TeleDongle is not receiving
172 this data, you can disconnect 'cu' from the Teledongle using the
173 procedures mentioned above and THEN connect to the TeleDongle from
174 inside 'ao-view'. If this doesn't work, disconnect from the
175 TeleDongle, unplug it, and try again after plugging it back in.
177 Eventually the GPS will find enough satellites, lock in on them,
178 and 'ao-view' will both auditorially announce and visually indicate
180 Now you can launch knowing that you have a good data path and
181 good satellite lock for flight data and recovery. Remember
182 you MUST tell ao-view to connect to the TeleDongle explicitly in
183 order for ao-view to be able to receive data.
185 Both RDF (radio direction finding) tones from the TeleMetrum and
186 GPS trekking data are available and together are very useful in
187 locating the rocket once it has landed. (The last good GPS data
188 received before touch-down will be on the data screen of 'ao-view'.)
190 Once you have recovered the rocket you can download the eeprom
191 contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over
192 either a USB cable or over the radio link using TeleDongle.
193 And by following the man page for 'ao-postflight' you can create
194 various data output reports, graphs, and even kml data to see the
195 flight trajectory in google-earth. (Moving the viewing angle making
196 sure to connect the yellow lines while in google-earth is the proper
199 As for ao-view.... some things are in the menu but don't do anything
200 very useful. The developers have stopped working on ao-view to focus
201 on a new, cross-platform ground station program. So ao-view may or
202 may not be updated in the future. Mostly you just use
203 the Log and Device menus. It has a wonderful display of the incoming
204 flight data and I am sure you will enjoy what it has to say to you
205 once you enable the voice output!
206 </p><div class="section" title="FAQ"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2574950"></a>FAQ</h2></div></div></div><p>
207 The altimeter (TeleMetrum) seems to shut off when disconnected from the
208 computer. Make sure the battery is adequately charged. Remember the
209 unit will pull more power than the USB port can deliver before the
210 GPS enters "locked" mode. The battery charges best when TeleMetrum
213 It's impossible to stop the TeleDongle when it's in "p" mode, I have
214 to unplug the USB cable? Make sure you have tried to "escape out" of
215 this mode. If this doesn't work the reboot procedure for the
216 TeleDongle *is* to simply unplug it. 'cu' however will retain it's
217 outgoing buffer IF your "escape out" ('~~') does not work.
218 At this point using either 'ao-view' (or possibly
219 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
222 The amber LED (on the TeleMetrum/altimeter) lights up when both
223 battery and USB are connected. Does this mean it's charging?
224 Yes, the yellow LED indicates the charging at the 'regular' rate.
225 If the led is out but the unit is still plugged into a USB port,
226 then the battery is being charged at a 'trickle' rate.
228 There are no "dit-dah-dah-dit" sound like the manual mentions?
229 That's the "pad" mode. Weak batteries might be the problem.
230 It is also possible that the unit is horizontal and the output
231 is instead a "dit-dit" meaning 'idle'.
233 It's unclear how to use 'ao-view' and other programs when 'cu'
234 is running. You cannot have more than one program connected to
235 the TeleDongle at one time without apparent data loss as the
236 incoming data will not make it to both programs intact.
237 Disconnect whatever programs aren't currently being used.
239 How do I save flight data?
240 Live telemetry is written to file(s) whenever 'ao-view' is connected
241 to the TeleDongle. The file area defaults to ~/altos
242 but is easily changed using the menus in 'ao-view'. The files that
243 are written end in '.telem'. The after-flight
244 data-dumped files will end in .eeprom and represent continuous data
245 unlike the rf-linked .telem files that are subject to the
246 turnarounds/data-packaging time slots in the half-duplex rf data path.
247 See the above instructions on what and how to save the eeprom stored
248 data after physically retrieving your TeleMetrum. Make sure to save
249 the on-board data after each flight, as the current firmware will
250 over-write any previous flight data during a new flight.
251 </p></div></div><div class="chapter" title="Chapter 3. Specifications"><div class="titlepage"><div><div><h2 class="title"><a name="id2562056"></a>Chapter 3. Specifications</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
252 Recording altimeter for model rocketry.
253 </p></li><li class="listitem"><p>
254 Supports dual deployment (can fire 2 ejection charges).
255 </p></li><li class="listitem"><p>
256 70cm ham-band transceiver for telemetry downlink.
257 </p></li><li class="listitem"><p>
258 Barometric pressure sensor good to 45k feet MSL.
259 </p></li><li class="listitem"><p>
260 1-axis high-g accelerometer for motor characterization, capable of
261 +/- 50g using default part.
262 </p></li><li class="listitem"><p>
263 On-board, integrated GPS receiver with 5hz update rate capability.
264 </p></li><li class="listitem"><p>
265 On-board 1 megabyte non-volatile memory for flight data storage.
266 </p></li><li class="listitem"><p>
267 USB interface for battery charging, configuration, and data recovery.
268 </p></li><li class="listitem"><p>
269 Fully integrated support for LiPo rechargeable batteries.
270 </p></li><li class="listitem"><p>
271 Uses LiPo to fire e-matches, support for optional separate pyro
273 </p></li><li class="listitem"><p>
274 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube.
275 </p></li></ul></div></div><div class="chapter" title="Chapter 4. Handling Precautions"><div class="titlepage"><div><div><h2 class="title"><a name="id2589910"></a>Chapter 4. Handling Precautions</h2></div></div></div><p>
276 TeleMetrum is a sophisticated electronic device. When handled gently and
277 properly installed in an airframe, it will deliver impressive results.
278 However, like all electronic devices, there are some precautions you
281 The Lithium Polymer rechargeable batteries used with TeleMetrum have an
282 extraordinary power density. This is great because we can fly with
283 much less battery mass than if we used alkaline batteries or previous
284 generation rechargeable batteries... but if they are punctured
285 or their leads are allowed to short, they can and will release their
287 Thus we recommend that you take some care when handling our batteries
288 and consider giving them some extra protection in your airframe. We
289 often wrap them in suitable scraps of closed-cell packing foam before
290 strapping them down, for example.
292 The TeleMetrum barometric sensor is sensitive to sunlight. In normal
293 mounting situations, it and all of the other surface mount components
294 are "down" towards whatever the underlying mounting surface is, so
295 this is not normally a problem. Please consider this, though, when
296 designing an installation, for example, in a 29mm airframe with a
297 see-through plastic payload bay.
299 The TeleMetrum barometric sensor sampling port must be able to
301 both by not being covered by foam or tape or other materials that might
302 directly block the hole on the top of the sensor, but also by having a
303 suitable static vent to outside air.
305 As with all other rocketry electronics, TeleMetrum must be protected
306 from exposure to corrosive motor exhaust and ejection charge gasses.
307 </p></div><div class="chapter" title="Chapter 5. Hardware Overview"><div class="titlepage"><div><div><h2 class="title"><a name="id2562288"></a>Chapter 5. Hardware Overview</h2></div></div></div><p>
308 TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to
309 fit inside coupler for 29mm airframe tubing, but using it in a tube that
310 small in diameter may require some creativity in mounting and wiring
311 to succeed! The default 1/4
312 wave UHF wire antenna attached to the center of the nose-cone end of
313 the board is about 7 inches long, and wiring for a power switch and
314 the e-matches for apogee and main ejection charges depart from the
315 fin can end of the board. Given all this, an ideal "simple" avionics
316 bay for TeleMetrum should have at least 10 inches of interior length.
318 A typical TeleMetrum installation using the on-board GPS antenna and
319 default wire UHF antenna involves attaching only a suitable
320 Lithium Polymer battery, a single pole switch for power on/off, and
321 two pairs of wires connecting e-matches for the apogee and main ejection
324 By default, we use the unregulated output of the LiPo battery directly
325 to fire ejection charges. This works marvelously with standard
326 low-current e-matches like the J-Tek from MJG Technologies, and with
327 Quest Q2G2 igniters. However, if you
328 want or need to use a separate pyro battery, you can do so by adding
329 a second 2mm connector to position B2 on the board and cutting the
330 thick pcb trace connecting the LiPo battery to the pyro circuit between
331 the two silk screen marks on the surface mount side of the board shown
334 We offer two choices of pyro and power switch connector, or you can
335 choose neither and solder wires directly to the board. All three choices
336 are reasonable depending on the constraints of your airframe. Our
337 favorite option when there is sufficient room above the board is to use
338 the Tyco pin header with polarization and locking. If you choose this
339 option, you crimp individual wires for the power switch and e-matches
340 into a mating connector, and installing and removing the TeleMetrum
341 board from an airframe is as easy as plugging or unplugging two
342 connectors. If the airframe will not support this much height or if
343 you want to be able to directly attach e-match leads to the board, we
344 offer a screw terminal block. This is very similar to what most other
345 altimeter vendors provide and so may be the most familiar option.
346 You'll need a very small straight blade screwdriver to connect
347 and disconnect the board in this case, such as you might find in a
348 jeweler's screwdriver set. Finally, you can forego both options and
349 solder wires directly to the board, which may be the best choice for
350 minimum diameter and/or minimum mass designs.
352 For most airframes, the integrated GPS antenna and wire UHF antenna are
353 a great combination. However, if you are installing in a carbon-fiber
354 electronics bay which is opaque to RF signals, you may need to use
355 off-board external antennas instead. In this case, you can order
356 TeleMetrum with an SMA connector for the UHF antenna connection, and
357 you can unplug the integrated GPS antenna and select an appropriate
358 off-board GPS antenna with cable terminating in a U.FL connector.
359 </p></div><div class="chapter" title="Chapter 6. System Operation"><div class="titlepage"><div><div><h2 class="title"><a name="id2568154"></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="#id2571301">Firmware Modes </a></span></dt><dt><span class="section"><a href="#id2573013">GPS </a></span></dt><dt><span class="section"><a href="#id2587417">Ground Testing </a></span></dt><dt><span class="section"><a href="#id2587414">Radio Link </a></span></dt><dt><span class="section"><a href="#id2558135">Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#id2578406">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2569320">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2587127">Main Deployment Altitude</a></span></dt></dl></dd><dt><span class="section"><a href="#id2565755">Calibration</a></span></dt><dd><dl><dt><span class="section"><a href="#id2589478">Radio Frequency</a></span></dt><dt><span class="section"><a href="#id2579588">Accelerometer</a></span></dt></dl></dd><dt><span class="section"><a href="#id2587826">Updating Device Firmware</a></span></dt><dd><dl><dt><span class="section"><a href="#id2560725">Updating TeleMetrum Firmware</a></span></dt><dt><span class="section"><a href="#id2579530">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="id2571301"></a>Firmware Modes </h2></div></div></div><p>
360 The AltOS firmware build for TeleMetrum has two fundamental modes,
361 "idle" and "flight". Which of these modes the firmware operates in
362 is determined by the orientation of the rocket (well, actually the
363 board, of course...) at the time power is switched on. If the rocket
364 is "nose up", then TeleMetrum assumes it's on a rail or rod being
365 prepared for launch, so the firmware chooses flight mode. However,
366 if the rocket is more or less horizontal, the firmware instead enters
369 At power on, you will hear three beeps
370 ("S" in Morse code for startup) and then a pause while
371 TeleMetrum completes initialization and self tests, and decides which
374 In flight or "pad" mode, TeleMetrum turns on the GPS system,
376 state machine, goes into transmit-only mode on the RF link sending
377 telemetry, and waits for launch to be detected. Flight mode is
378 indicated by an audible "di-dah-dah-dit" ("P" for pad) on the
380 beeps indicating the state of the pyrotechnic igniter continuity.
381 One beep indicates apogee continuity, two beeps indicate
382 main continuity, three beeps indicate both apogee and main continuity,
383 and one longer "brap" sound indicates no continuity. For a dual
384 deploy flight, make sure you're getting three beeps before launching!
385 For apogee-only or motor eject flights, do what makes sense.
387 In idle mode, you will hear an audible "di-dit" ("I" for idle), and
388 the normal flight state machine is disengaged, thus
389 no ejection charges will fire. TeleMetrum also listens on the RF
390 link when in idle mode for packet mode requests sent from TeleDongle.
391 Commands can be issued to a TeleMetrum in idle mode over either
392 USB or the RF link equivalently.
393 Idle mode is useful for configuring TeleMetrum, for extracting data
394 from the on-board storage chip after flight, and for ground testing
397 One "neat trick" of particular value when TeleMetrum is used with very
398 large airframes, is that you can power the board up while the rocket
399 is horizontal, such that it comes up in idle mode. Then you can
400 raise the airframe to launch position, use a TeleDongle to open
401 a packet connection, and issue a 'reset' command which will cause
402 TeleMetrum to reboot, realize it's now nose-up, and thus choose
403 flight mode. This is much safer than standing on the top step of a
404 rickety step-ladder or hanging off the side of a launch tower with
405 a screw-driver trying to turn on your avionics before installing
407 </p></div><div class="section" title="GPS"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2573013"></a>GPS </h2></div></div></div><p>
408 TeleMetrum includes a complete GPS receiver. See a later section for
409 a brief explanation of how GPS works that will help you understand
410 the information in the telemetry stream. The bottom line is that
411 the TeleMetrum GPS receiver needs to lock onto at least four
412 satellites to obtain a solid 3 dimensional position fix and know
415 TeleMetrum provides backup power to the GPS chip any time a LiPo
416 battery is connected. This allows the receiver to "warm start" on
417 the launch rail much faster than if every power-on were a "cold start"
418 for the GPS receiver. In typical operations, powering up TeleMetrum
419 on the flight line in idle mode while performing final airframe
420 preparation will be sufficient to allow the GPS receiver to cold
421 start and acquire lock. Then the board can be powered down during
422 RSO review and installation on a launch rod or rail. When the board
423 is turned back on, the GPS system should lock very quickly, typically
424 long before igniter installation and return to the flight line are
426 </p></div><div class="section" title="Ground Testing"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2587417"></a>Ground Testing </h2></div></div></div><p>
427 An important aspect of preparing a rocket using electronic deployment
428 for flight is ground testing the recovery system. Thanks
429 to the bi-directional RF link central to the Altus Metrum system,
430 this can be accomplished in a TeleMetrum-equipped rocket without as
431 much work as you may be accustomed to with other systems. It can
434 Just prep the rocket for flight, then power up TeleMetrum while the
435 airframe is horizontal. This will cause the firmware to go into
436 "idle" mode, in which the normal flight state machine is disabled and
437 charges will not fire without manual command. Then, establish an
438 RF packet connection from a TeleDongle-equipped computer using the
439 P command from a safe distance. You can now command TeleMetrum to
440 fire the apogee or main charges to complete your testing.
442 In order to reduce the chance of accidental firing of pyrotechnic
443 charges, the command to fire a charge is intentionally somewhat
444 difficult to type, and the built-in help is slightly cryptic to
445 prevent accidental echoing of characters from the help text back at
446 the board from firing a charge. The command to fire the apogee
447 drogue charge is 'i DoIt drogue' and the command to fire the main
448 charge is 'i DoIt main'.
449 </p></div><div class="section" title="Radio Link"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2587414"></a>Radio Link </h2></div></div></div><p>
450 The chip our boards are based on incorporates an RF transceiver, but
451 it's not a full duplex system... each end can only be transmitting or
452 receiving at any given moment. So we had to decide how to manage the
455 By design, TeleMetrum firmware listens for an RF connection when
456 it's in "idle mode" (turned on while the rocket is horizontal), which
457 allows us to use the RF link to configure the rocket, do things like
458 ejection tests, and extract data after a flight without having to
459 crack open the airframe. However, when the board is in "flight
460 mode" (turned on when the rocket is vertical) the TeleMetrum only
461 transmits and doesn't listen at all. That's because we want to put
462 ultimate priority on event detection and getting telemetry out of
463 the rocket and out over
464 the RF link in case the rocket crashes and we aren't able to extract
467 We don't use a 'normal packet radio' mode because they're just too
468 inefficient. The GFSK modulation we use is just FSK with the
469 baseband pulses passed through a
470 Gaussian filter before they go into the modulator to limit the
471 transmitted bandwidth. When combined with the hardware forward error
472 correction support in the cc1111 chip, this allows us to have a very
473 robust 38.4 kilobit data link with only 10 milliwatts of transmit power,
474 a whip antenna in the rocket, and a hand-held Yagi on the ground. We've
475 had flights to above 21k feet AGL with good reception, and calculations
476 suggest we should be good to well over 40k feet AGL with a 5-element yagi on
477 the ground. We hope to fly boards to higher altitudes soon, and would
478 of course appreciate customer feedback on performance in higher
480 </p></div><div class="section" title="Configurable Parameters"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2558135"></a>Configurable Parameters</h2></div></div></div><p>
481 Configuring a TeleMetrum board for flight is very simple. Because we
482 have both acceleration and pressure sensors, there is no need to set
483 a "mach delay", for example. The few configurable parameters can all
484 be set using a simple terminal program over the USB port or RF link
486 </p><div class="section" title="Radio Channel"><div class="titlepage"><div><div><h3 class="title"><a name="id2578406"></a>Radio Channel</h3></div></div></div><p>
487 Our firmware supports 10 channels. The default channel 0 corresponds
488 to a center frequency of 434.550 Mhz, and channels are spaced every
489 100 khz. Thus, channel 1 is 434.650 Mhz, and channel 9 is 435.550 Mhz.
490 At any given launch, we highly recommend coordinating who will use
491 each channel and when to avoid interference. And of course, both
492 TeleMetrum and TeleDongle must be configured to the same channel to
493 successfully communicate with each other.
495 To set the radio channel, use the 'c r' command, like 'c r 3' to set
497 As with all 'c' sub-commands, follow this with a 'c w' to write the
498 change to the parameter block in the on-board DataFlash chip on
499 your TeleMetrum board if you want the change to stay in place across reboots.
500 </p></div><div class="section" title="Apogee Delay"><div class="titlepage"><div><div><h3 class="title"><a name="id2569320"></a>Apogee Delay</h3></div></div></div><p>
501 Apogee delay is the number of seconds after TeleMetrum detects flight
502 apogee that the drogue charge should be fired. In most cases, this
503 should be left at the default of 0. However, if you are flying
504 redundant electronics such as for an L3 certification, you may wish
505 to set one of your altimeters to a positive delay so that both
506 primary and backup pyrotechnic charges do not fire simultaneously.
508 To set the apogee delay, use the 'c d' command.
509 As with all 'c' sub-commands, follow this with a 'c w' to write the
510 change to the parameter block in the on-board DataFlash chip.
512 Please note that the TeleMetrum apogee detection algorithm always
513 fires a fraction of a second *after* apogee. If you are also flying
514 an altimeter like the PerfectFlite MAWD, which only supports selecting
515 0 or 1 seconds of apogee delay, you may wish to set the MAWD to 0
516 seconds delay and set the TeleMetrum to fire your backup 2 or 3
517 seconds later to avoid any chance of both charges firing
518 simultaneously. We've flown several airframes this way quite happily,
519 including Keith's successful L3 cert.
520 </p></div><div class="section" title="Main Deployment Altitude"><div class="titlepage"><div><div><h3 class="title"><a name="id2587127"></a>Main Deployment Altitude</h3></div></div></div><p>
521 By default, TeleMetrum will fire the main deployment charge at an
522 elevation of 250 meters (about 820 feet) above ground. We think this
523 is a good elevation for most airframes, but feel free to change this
524 to suit. In particular, if you are flying two altimeters, you may
526 deployment elevation for the backup altimeter to be something lower
527 than the primary so that both pyrotechnic charges don't fire
530 To set the main deployment altitude, use the 'c m' command.
531 As with all 'c' sub-commands, follow this with a 'c w' to write the
532 change to the parameter block in the on-board DataFlash chip.
533 </p></div></div><div class="section" title="Calibration"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2565755"></a>Calibration</h2></div></div></div><p>
534 There are only two calibrations required for a TeleMetrum board, and
535 only one for TeleDongle.
536 </p><div class="section" title="Radio Frequency"><div class="titlepage"><div><div><h3 class="title"><a name="id2589478"></a>Radio Frequency</h3></div></div></div><p>
537 The radio frequency is synthesized from a clock based on the 48 Mhz
538 crystal on the board. The actual frequency of this oscillator must be
539 measured to generate a calibration constant. While our GFSK modulation
540 bandwidth is wide enough to allow boards to communicate even when
541 their oscillators are not on exactly the same frequency, performance
542 is best when they are closely matched.
543 Radio frequency calibration requires a calibrated frequency counter.
544 Fortunately, once set, the variation in frequency due to aging and
545 temperature changes is small enough that re-calibration by customers
546 should generally not be required.
548 To calibrate the radio frequency, connect the UHF antenna port to a
549 frequency counter, set the board to channel 0, and use the 'C'
550 command to generate a CW carrier. Wait for the transmitter temperature
551 to stabilize and the frequency to settle down.
552 Then, divide 434.550 Mhz by the
553 measured frequency and multiply by the current radio cal value show
554 in the 'c s' command. For an unprogrammed board, the default value
555 is 1186611. Take the resulting integer and program it using the 'c f'
556 command. Testing with the 'C' command again should show a carrier
557 within a few tens of Hertz of the intended frequency.
558 As with all 'c' sub-commands, follow this with a 'c w' to write the
559 change to the parameter block in the on-board DataFlash chip.
560 </p></div><div class="section" title="Accelerometer"><div class="titlepage"><div><div><h3 class="title"><a name="id2579588"></a>Accelerometer</h3></div></div></div><p>
561 The accelerometer we use has its own 5 volt power supply and
562 the output must be passed through a resistive voltage divider to match
563 the input of our 3.3 volt ADC. This means that unlike the barometric
564 sensor, the output of the acceleration sensor is not ratiometric to
565 the ADC converter, and calibration is required. We also support the
566 use of any of several accelerometers from a Freescale family that
567 includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity,
568 a simple 2-point calibration yields acceptable results capturing both
569 the different sensitivities and ranges of the different accelerometer
570 parts and any variation in power supply voltages or resistor values
571 in the divider network.
573 To calibrate the acceleration sensor, use the 'c a 0' command. You
574 will be prompted to orient the board vertically with the UHF antenna
575 up and press a key, then to orient the board vertically with the
576 UHF antenna down and press a key.
577 As with all 'c' sub-commands, follow this with a 'c w' to write the
578 change to the parameter block in the on-board DataFlash chip.
580 The +1g and -1g calibration points are included in each telemetry
581 frame and are part of the header extracted by ao-dumplog after flight.
582 Note that we always store and return raw ADC samples for each
583 sensor... nothing is permanently "lost" or "damaged" if the
586 In the unlikely event an accel cal that goes badly, it is possible
587 that TeleMetrum may always come up in 'pad mode' and as such not be
588 listening to either the USB or radio interfaces. If that happens,
589 there is a special hook in the firmware to force the board back
590 in to 'idle mode' so you can re-do the cal. To use this hook, you
591 just need to ground the SPI clock pin at power-on. This pin is
592 available as pin 2 on the 8-pin companion connector, and pin 1 is
593 ground. So either carefully install a fine-gauge wire jumper
594 between the two pins closest to the index hole end of the 8-pin
595 connector, or plug in the programming cable to the 8-pin connector
596 and use a small screwdriver or similar to short the two pins closest
597 to the index post on the 4-pin end of the programming cable, and
598 power up the board. It should come up in 'idle mode' (two beeps).
599 </p></div></div><div class="section" title="Updating Device Firmware"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2587826"></a>Updating Device Firmware</h2></div></div></div><p>
600 The big conceptual thing to realize is that you have to use a
601 TeleDongle as a programmer to update a TeleMetrum, and vice versa.
602 Due to limited memory resources in the cc1111, we don't support
603 programming either unit directly over USB.
605 You may wish to begin by ensuring you have current firmware images.
606 These are distributed as part of the AltOS software bundle that
607 also includes the AltosUI ground station program. Newer ground
608 station versions typically work fine with older firmware versions,
609 so you don't need to update your devices just to try out new
610 software features. You can always download the most recent
611 version from <a class="ulink" href="http://www.altusmetrum.org/AltOS/" target="_top">http://www.altusmetrum.org/AltOS/</a>.
613 We recommend updating TeleMetrum first, before updating TeleDongle.
614 </p><div class="section" title="Updating TeleMetrum Firmware"><div class="titlepage"><div><div><h3 class="title"><a name="id2560725"></a>Updating TeleMetrum Firmware</h3></div></div></div><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
615 Find the 'programming cable' that you got as part of the starter
616 kit, that has a red 8-pin MicroMaTch connector on one end and a
617 red 4-pin MicroMaTch connector on the other end.
618 </li><li class="listitem">
619 Take the 2 screws out of the TeleDongle case to get access
620 to the circuit board.
621 </li><li class="listitem">
622 Plug the 8-pin end of the programming cable to the
623 matching connector on the TeleDongle, and the 4-pin end to the
624 matching connector on the TeleMetrum.
625 Note that each MicroMaTch connector has an alignment pin that
626 goes through a hole in the PC board when you have the cable
628 </li><li class="listitem">
629 Attach a battery to the TeleMetrum board.
630 </li><li class="listitem">
631 Plug the TeleDongle into your computer's USB port, and power
633 </li><li class="listitem">
634 Run AltosUI, and select 'Flash Image' from the File menu.
635 </li><li class="listitem">
636 Pick the TeleDongle device from the list, identifying it as the
638 </li><li class="listitem">
639 Select the image you want put on the TeleMetrum, which should have a
640 name in the form telemetrum-v1.0-0.7.1.ihx. It should be visible
641 in the default directory, if not you may have to poke around
642 your system to find it.
643 </li><li class="listitem">
644 Make sure the configuration parameters are reasonable
645 looking. If the serial number and/or RF configuration
646 values aren't right, you'll need to change them.
647 </li><li class="listitem">
648 Hit the 'OK' button and the software should proceed to flash
649 the TeleMetrum with new firmware, showing a progress bar.
650 </li><li class="listitem">
651 Confirm that the TeleMetrum board seems to have updated ok, which you
652 can do by plugging in to it over USB and using a terminal program
653 to connect to the board and issue the 'v' command to check
655 </li><li class="listitem">
656 If something goes wrong, give it another try.
657 </li></ol></div></div><div class="section" title="Updating TeleDongle Firmware"><div class="titlepage"><div><div><h3 class="title"><a name="id2579530"></a>Updating TeleDongle Firmware</h3></div></div></div><p>
658 Updating TeleDongle's firmware is just like updating TeleMetrum
659 firmware, but you switch which board is the programmer and which
660 is the programming target.
661 </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
662 Find the 'programming cable' that you got as part of the starter
663 kit, that has a red 8-pin MicroMaTch connector on one end and a
664 red 4-pin MicroMaTch connector on the other end.
665 </li><li class="listitem">
666 Find the USB cable that you got as part of the starter kit, and
667 plug the "mini" end in to the mating connector on TeleMetrum.
668 </li><li class="listitem">
669 Take the 2 screws out of the TeleDongle case to get access
670 to the circuit board.
671 </li><li class="listitem">
672 Plug the 8-pin end of the programming cable to the (latching)
673 matching connector on the TeleMetrum, and the 4-pin end to the
674 matching connector on the TeleDongle.
675 Note that each MicroMaTch connector has an alignment pin that
676 goes through a hole in the PC board when you have the cable
678 </li><li class="listitem">
679 Attach a battery to the TeleMetrum board.
680 </li><li class="listitem">
681 Plug both TeleMetrum and TeleDongle into your computer's USB
682 ports, and power up the TeleMetrum.
683 </li><li class="listitem">
684 Run AltosUI, and select 'Flash Image' from the File menu.
685 </li><li class="listitem">
686 Pick the TeleMetrum device from the list, identifying it as the
688 </li><li class="listitem">
689 Select the image you want put on the TeleDongle, which should have a
690 name in the form teledongle-v0.2-0.7.1.ihx. It should be visible
691 in the default directory, if not you may have to poke around
692 your system to find it.
693 </li><li class="listitem">
694 Make sure the configuration parameters are reasonable
695 looking. If the serial number and/or RF configuration
696 values aren't right, you'll need to change them. The TeleDongle
697 serial number is on the "bottom" of the circuit board, and can
698 usually be read through the translucent blue plastic case without
699 needing to remove the board from the case.
700 </li><li class="listitem">
701 Hit the 'OK' button and the software should proceed to flash
702 the TeleDongle with new firmware, showing a progress bar.
703 </li><li class="listitem">
704 Confirm that the TeleDongle board seems to have updated ok, which you
705 can do by plugging in to it over USB and using a terminal program
706 to connect to the board and issue the 'v' command to check
707 the version, etc. Once you're happy, remove the programming cable
708 and put the cover back on the TeleDongle.
709 </li><li class="listitem">
710 If something goes wrong, give it another try.
712 Be careful removing the programming cable from the locking 8-pin
713 connector on TeleMetrum. You'll need a fingernail or perhaps a thin
714 screwdriver or knife blade to gently pry the locking ears out
715 slightly to extract the connector. We used a locking connector on
716 TeleMetrum to help ensure that the cabling to companion boards
717 used in a rocket don't ever come loose accidentally in flight.
718 </p></div></div></div><div class="chapter" title="Chapter 7. AltosUI"><div class="titlepage"><div><div><h2 class="title"><a name="id2576399"></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="#id2576677">Packet Command Mode</a></span></dt><dt><span class="section"><a href="#id2581723">Monitor Flight</a></span></dt><dd><dl><dt><span class="section"><a href="#id2576742">Launch Pad</a></span></dt><dt><span class="section"><a href="#id2571392">Ascent</a></span></dt><dt><span class="section"><a href="#id2578242">Descent</a></span></dt><dt><span class="section"><a href="#id2586734">Landed</a></span></dt><dt><span class="section"><a href="#id2568067">Site Map</a></span></dt></dl></dd><dt><span class="section"><a href="#id2572352">Save Flight Data</a></span></dt><dt><span class="section"><a href="#id2592536">Replay Flight</a></span></dt><dt><span class="section"><a href="#id2579359">Graph Data</a></span></dt><dt><span class="section"><a href="#id2574359">Export Data</a></span></dt><dd><dl><dt><span class="section"><a href="#id2581561">Comma Separated Value Format</a></span></dt><dt><span class="section"><a href="#id2585122">Keyhole Markup Language (for Google Earth)</a></span></dt></dl></dd><dt><span class="section"><a href="#id2576382">Configure TeleMetrum</a></span></dt><dd><dl><dt><span class="section"><a href="#id2565240">Main Deploy Altitude</a></span></dt><dt><span class="section"><a href="#id2558922">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2588372">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2569947">Radio Calibration</a></span></dt><dt><span class="section"><a href="#id2567826">Callsign</a></span></dt></dl></dd><dt><span class="section"><a href="#id2567986">Configure AltosUI</a></span></dt><dd><dl><dt><span class="section"><a href="#id2554292">Voice Settings</a></span></dt><dt><span class="section"><a href="#id2592599">Log Directory</a></span></dt><dt><span class="section"><a href="#id2559399">Callsign</a></span></dt></dl></dd><dt><span class="section"><a href="#id2579274">Flash Image</a></span></dt><dt><span class="section"><a href="#id2577046">Fire Igniter</a></span></dt></dl></div><p>
719 The AltosUI program provides a graphical user interface for
720 interacting with the Altus Metrum product family, including
721 TeleMetrum and TeleDongle. AltosUI can monitor telemetry data,
722 configure TeleMetrum and TeleDongle devices and many other
723 tasks. The primary interface window provides a selection of
724 buttons, one for each major activity in the system. This manual
725 is split into chapters, each of which documents one of the tasks
726 provided from the top-level toolbar.
727 </p><div class="section" title="Packet Command Mode"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2576677"></a>Packet Command Mode</h2></div><div><h3 class="subtitle">Controlling TeleMetrum Over The Radio Link</h3></div></div></div><p>
728 One of the unique features of the Altos Metrum environment is
729 the ability to create a two way command link between TeleDongle
730 and TeleMetrum using the digital radio transceivers built into
731 each device. This allows you to interact with TeleMetrum from
732 afar, as if it were directly connected to the computer.
734 Any operation which can be performed with TeleMetrum
735 can either be done with TeleMetrum directly connected to
736 the computer via the USB cable, or through the packet
737 link. Simply select the appropriate TeleDongle device when
738 the list of devices is presented and AltosUI will use packet
741 One oddity in the current interface is how AltosUI selects the
742 channel for packet mode communications. Instead of providing
743 an interface to specifically configure the channel, it uses
744 whatever channel was most recently selected for the target
745 TeleDongle device in Monitor Flight mode. If you haven't ever
746 used that mode with the TeleDongle in question, select the
747 Monitor Flight button from the top level UI, pick the
748 appropriate TeleDongle device. Once the flight monitoring
749 window is open, select the desired channel and then close it
750 down again. All Packet Command Mode operations will now use
752 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
753 Save Flight Data—Recover flight data from the rocket without
755 </p></li><li class="listitem"><p>
756 Configure TeleMetrum—Reset apogee delays or main deploy
757 heights to respond to changing launch conditions. You can
758 also 'reboot' the TeleMetrum device. Use this to remotely
759 enable the flight computer by turning TeleMetrum on while
760 horizontal, then once the airframe is oriented for launch,
761 you can reboot TeleMetrum and have it restart in pad mode
762 without having to climb the scary ladder.
763 </p></li><li class="listitem"><p>
764 Fire Igniters—Test your deployment charges without snaking
765 wires out through holes in the airframe. Simply assembly the
766 rocket as if for flight with the apogee and main charges
767 loaded, then remotely command TeleMetrum to fire the
769 </p></li></ul></div><p>
770 Packet command mode uses the same RF channels as telemetry
771 mode. Configure the desired TeleDongle channel using the
772 flight monitor window channel selector and then close that
773 window before performing the desired operation.
775 TeleMetrum only enables packet command mode in 'idle' mode, so
776 make sure you have TeleMetrum lying horizontally when you turn
777 it on. Otherwise, TeleMetrum will start in 'pad' mode ready for
778 flight and will not be listening for command packets from TeleDongle.
780 When packet command mode is enabled, you can monitor the link
781 by watching the lights on the TeleDongle and TeleMetrum
782 devices. The red LED will flash each time TeleDongle or
783 TeleMetrum transmit a packet while the green LED will light up
784 on TeleDongle while it is waiting to receive a packet from
786 </p></div><div class="section" title="Monitor Flight"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2581723"></a>Monitor Flight</h2></div><div><h3 class="subtitle">Receive, Record and Display Telemetry Data</h3></div></div></div><p>
787 Selecting this item brings up a dialog box listing all of the
788 connected TeleDongle devices. When you choose one of these,
789 AltosUI will create a window to display telemetry data as
790 received by the selected TeleDongle device.
792 All telemetry data received are automatically recorded in
793 suitable log files. The name of the files includes the current
794 date and rocket serial and flight numbers.
796 The radio channel being monitored by the TeleDongle device is
797 displayed at the top of the window. You can configure the
798 channel by clicking on the channel box and selecting the desired
799 channel. AltosUI remembers the last channel selected for each
800 TeleDongle and selects that automatically the next time you use
803 Below the TeleDongle channel selector, the window contains a few
804 significant pieces of information about the TeleMetrum providing
805 the telemetry data stream:
806 </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
808 </p></li><li class="listitem"><p>
809 The rocket flight state. Each flight passes through several
810 states including Pad, Boost, Fast, Coast, Drogue, Main and
812 </p></li><li class="listitem"><p>
813 The Received Signal Strength Indicator value. This lets
814 you know how strong a signal TeleDongle is receiving. The
815 radio inside TeleDongle operates down to about -99dBm;
816 weaker signals may not be receiveable. The packet link uses
817 error correction and detection techniques which prevent
818 incorrect data from being reported.
819 </p></li></ul></div><p>
820 Finally, the largest portion of the window contains a set of
821 tabs, each of which contain some information about the rocket.
822 They're arranged in 'flight order' so that as the flight
823 progresses, the selected tab automatically switches to display
824 data relevant to the current state of the flight. You can select
825 other tabs at any time. The final 'table' tab contains all of
826 the telemetry data in one place.
827 </p><div class="section" title="Launch Pad"><div class="titlepage"><div><div><h3 class="title"><a name="id2576742"></a>Launch Pad</h3></div></div></div><p>
828 The 'Launch Pad' tab shows information used to decide when the
829 rocket is ready for flight. The first elements include red/green
830 indicators, if any of these is red, you'll want to evaluate
831 whether the rocket is ready to launch:
832 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
833 Battery Voltage. This indicates whether the LiPo battery
834 powering the TeleMetrum has sufficient charge to last for
835 the duration of the flight. A value of more than
836 3.7V is required for a 'GO' status.
837 </p></li><li class="listitem"><p>
838 Apogee Igniter Voltage. This indicates whether the apogee
839 igniter has continuity. If the igniter has a low
840 resistance, then the voltage measured here will be close
841 to the LiPo battery voltage. A value greater than 3.2V is
842 required for a 'GO' status.
843 </p></li><li class="listitem"><p>
844 Main Igniter Voltage. This indicates whether the main
845 igniter has continuity. If the igniter has a low
846 resistance, then the voltage measured here will be close
847 to the LiPo battery voltage. A value greater than 3.2V is
848 required for a 'GO' status.
849 </p></li><li class="listitem"><p>
850 GPS Locked. This indicates whether the GPS receiver is
851 currently able to compute position information. GPS requires
852 at least 4 satellites to compute an accurate position.
853 </p></li><li class="listitem"><p>
854 GPS Ready. This indicates whether GPS has reported at least
855 10 consecutive positions without losing lock. This ensures
856 that the GPS receiver has reliable reception from the
858 </p></li></ul></div><p>
860 The LaunchPad tab also shows the computed launch pad position
861 and altitude, averaging many reported positions to improve the
864 </p></div><div class="section" title="Ascent"><div class="titlepage"><div><div><h3 class="title"><a name="id2571392"></a>Ascent</h3></div></div></div><p>
865 This tab is shown during Boost, Fast and Coast
866 phases. The information displayed here helps monitor the
867 rocket as it heads towards apogee.
869 The height, speed and acceleration are shown along with the
870 maxium values for each of them. This allows you to quickly
871 answer the most commonly asked questions you'll hear during
874 The current latitude and longitude reported by the GPS are
875 also shown. Note that under high acceleration, these values
876 may not get updated as the GPS receiver loses position
877 fix. Once the rocket starts coasting, the receiver should
878 start reporting position again.
880 Finally, the current igniter voltages are reported as in the
881 Launch Pad tab. This can help diagnose deployment failures
882 caused by wiring which comes loose under high acceleration.
883 </p></div><div class="section" title="Descent"><div class="titlepage"><div><div><h3 class="title"><a name="id2578242"></a>Descent</h3></div></div></div><p>
884 Once the rocket has reached apogee and (we hope) activated the
885 apogee charge, attention switches to tracking the rocket on
886 the way back to the ground, and for dual-deploy flights,
887 waiting for the main charge to fire.
889 To monitor whether the apogee charge operated correctly, the
890 current descent rate is reported along with the current
891 height. Good descent rates generally range from 15-30m/s.
893 To help locate the rocket in the sky, use the elevation and
894 bearing information to figure out where to look. Elevation is
895 in degrees above the horizon. Bearing is reported in degrees
896 relative to true north. Range can help figure out how big the
897 rocket will appear. Note that all of these values are relative
898 to the pad location. If the elevation is near 90°, the rocket
899 is over the pad, not over you.
901 Finally, the igniter voltages are reported in this tab as
902 well, both to monitor the main charge as well as to see what
903 the status of the apogee charge is.
904 </p></div><div class="section" title="Landed"><div class="titlepage"><div><div><h3 class="title"><a name="id2586734"></a>Landed</h3></div></div></div><p>
905 Once the rocket is on the ground, attention switches to
906 recovery. While the radio signal is generally lost once the
907 rocket is on the ground, the last reported GPS position is
908 generally within a short distance of the actual landing location.
910 The last reported GPS position is reported both by
911 latitude and longitude as well as a bearing and distance from
912 the launch pad. The distance should give you a good idea of
913 whether you'll want to walk or hitch a ride. Take the reported
914 latitude and longitude and enter them into your handheld GPS
915 unit and have that compute a track to the landing location.
917 Finally, the maximum height, speed and acceleration reported
918 during the flight are displayed for your admiring observers.
919 </p></div><div class="section" title="Site Map"><div class="titlepage"><div><div><h3 class="title"><a name="id2568067"></a>Site Map</h3></div></div></div><p>
920 When the rocket gets a GPS fix, the Site Map tab will map
921 the rocket's position to make it easier for you to locate the
922 rocket, both while it is in the air, and when it has landed. The
923 rocket's state is indicated by colour: white for pad, red for
924 boost, pink for fast, yellow for coast, light blue for drogue,
925 dark blue for main, and black for landed.
927 The map's scale is approximately 3m (10ft) per pixel. The map
928 can be dragged using the left mouse button. The map will attempt
929 to keep the rocket roughly centred while data is being received.
931 Images are fetched automatically via the Google Maps Static API,
932 and are cached for reuse. If map images cannot be downloaded,
933 the rocket's path will be traced on a dark grey background
935 </p></div></div><div class="section" title="Save Flight Data"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2572352"></a>Save Flight Data</h2></div></div></div><p>
936 TeleMetrum records flight data to its internal flash memory.
937 This data is recorded at a much higher rate than the telemetry
938 system can handle, and is not subject to radio drop-outs. As
939 such, it provides a more complete and precise record of the
940 flight. The 'Save Flight Data' button allows you to read the
941 flash memory and write it to disk.
943 Clicking on the 'Save Flight Data' button brings up a list of
944 connected TeleMetrum and TeleDongle devices. If you select a
945 TeleMetrum device, the flight data will be downloaded from that
946 device directly. If you select a TeleDongle device, flight data
947 will be downloaded from a TeleMetrum device connected via the
948 packet command link to the specified TeleDongle. See the chapter
949 on Packet Command Mode for more information about this.
951 The filename for the data is computed automatically from the recorded
952 flight date, TeleMetrum serial number and flight number
954 </p></div><div class="section" title="Replay Flight"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2592536"></a>Replay Flight</h2></div></div></div><p>
955 Select this button and you are prompted to select a flight
956 record file, either a .telem file recording telemetry data or a
957 .eeprom file containing flight data saved from the TeleMetrum
960 Once a flight record is selected, the flight monitor interface
961 is displayed and the flight is re-enacted in real time. Check
962 the Monitor Flight chapter above to learn how this window operates.
963 </p></div><div class="section" title="Graph Data"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2579359"></a>Graph Data</h2></div></div></div><p>
964 Select this button and you are prompted to select a flight
965 record file, either a .telem file recording telemetry data or a
966 .eeprom file containing flight data saved from the TeleMetrum
969 Once a flight record is selected, the acceleration (blue),
970 velocity (green) and altitude (red) of the flight are plotted and
971 displayed, measured in metric units.
973 The graph can be zoomed into a particular area by clicking and
974 dragging down and to the right. Once zoomed, the graph can be
975 reset by clicking and dragging up and to the left. Holding down
976 control and clicking and dragging allows the graph to be panned.
977 The right mouse button causes a popup menu to be displayed, giving
978 you the option save or print the plot.
980 Note that telemetry files will generally produce poor graphs
981 due to the lower sampling rate and missed telemetry packets,
982 and will also often have significant amounts of data received
983 while the rocket was waiting on the pad. Use saved flight data
984 for graphing where possible.
985 </p></div><div class="section" title="Export Data"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2574359"></a>Export Data</h2></div></div></div><p>
986 This tool takes the raw data files and makes them available for
987 external analysis. When you select this button, you are prompted to select a flight
988 data file (either .eeprom or .telem will do, remember that
989 .eeprom files contain higher resolution and more continuous
990 data). Next, a second dialog appears which is used to select
991 where to write the resulting file. It has a selector to choose
992 between CSV and KML file formats.
993 </p><div class="section" title="Comma Separated Value Format"><div class="titlepage"><div><div><h3 class="title"><a name="id2581561"></a>Comma Separated Value Format</h3></div></div></div><p>
994 This is a text file containing the data in a form suitable for
995 import into a spreadsheet or other external data analysis
996 tool. The first few lines of the file contain the version and
997 configuration information from the TeleMetrum device, then
998 there is a single header line which labels all of the
999 fields. All of these lines start with a '#' character which
1000 most tools can be configured to skip over.
1002 The remaining lines of the file contain the data, with each
1003 field separated by a comma and at least one space. All of
1004 the sensor values are converted to standard units, with the
1005 barometric data reported in both pressure, altitude and
1006 height above pad units.
1007 </p></div><div class="section" title="Keyhole Markup Language (for Google Earth)"><div class="titlepage"><div><div><h3 class="title"><a name="id2585122"></a>Keyhole Markup Language (for Google Earth)</h3></div></div></div><p>
1008 This is the format used by
1009 Googleearth to provide an overlay within that
1010 application. With this, you can use Googleearth to see the
1011 whole flight path in 3D.
1012 </p></div></div><div class="section" title="Configure TeleMetrum"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2576382"></a>Configure TeleMetrum</h2></div></div></div><p>
1013 Select this button and then select either a TeleMetrum or
1014 TeleDongle Device from the list provided. Selecting a TeleDongle
1015 device will use Packet Comamnd Mode to configure remote
1016 TeleMetrum device. Learn how to use this in the Packet Command
1019 The first few lines of the dialog provide information about the
1020 connected TeleMetrum device, including the product name,
1021 software version and hardware serial number. Below that are the
1022 individual configuration entries.
1024 At the bottom of the dialog, there are four buttons:
1025 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
1026 Save. This writes any changes to the TeleMetrum
1027 configuration parameter block in flash memory. If you don't
1028 press this button, any changes you make will be lost.
1029 </p></li><li class="listitem"><p>
1030 Reset. This resets the dialog to the most recently saved values,
1031 erasing any changes you have made.
1032 </p></li><li class="listitem"><p>
1033 Reboot. This reboots the TeleMetrum device. Use this to
1034 switch from idle to pad mode by rebooting once the rocket is
1035 oriented for flight.
1036 </p></li><li class="listitem"><p>
1037 Close. This closes the dialog. Any unsaved changes will be
1039 </p></li></ul></div><p>
1040 The rest of the dialog contains the parameters to be configured.
1041 </p><div class="section" title="Main Deploy Altitude"><div class="titlepage"><div><div><h3 class="title"><a name="id2565240"></a>Main Deploy Altitude</h3></div></div></div><p>
1042 This sets the altitude (above the recorded pad altitude) at
1043 which the 'main' igniter will fire. The drop-down menu shows
1044 some common values, but you can edit the text directly and
1045 choose whatever you like. If the apogee charge fires below
1046 this altitude, then the main charge will fire two seconds
1047 after the apogee charge fires.
1048 </p></div><div class="section" title="Apogee Delay"><div class="titlepage"><div><div><h3 class="title"><a name="id2558922"></a>Apogee Delay</h3></div></div></div><p>
1049 When flying redundant electronics, it's often important to
1050 ensure that multiple apogee charges don't fire at precisely
1051 the same time as that can overpressurize the apogee deployment
1052 bay and cause a structural failure of the airframe. The Apogee
1053 Delay parameter tells the flight computer to fire the apogee
1054 charge a certain number of seconds after apogee has been
1056 </p></div><div class="section" title="Radio Channel"><div class="titlepage"><div><div><h3 class="title"><a name="id2588372"></a>Radio Channel</h3></div></div></div><p>
1057 This configures which of the 10 radio channels to use for both
1058 telemetry and packet command mode. Note that if you set this
1059 value via packet command mode, you will have to reconfigure
1060 the TeleDongle channel before you will be able to use packet
1062 </p></div><div class="section" title="Radio Calibration"><div class="titlepage"><div><div><h3 class="title"><a name="id2569947"></a>Radio Calibration</h3></div></div></div><p>
1063 The radios in every Altus Metrum device are calibrated at the
1064 factory to ensure that they transmit and receive on the
1065 specified frequency for each channel. You can adjust that
1066 calibration by changing this value. To change the TeleDongle's
1067 calibration, you must reprogram the unit completely.
1068 </p></div><div class="section" title="Callsign"><div class="titlepage"><div><div><h3 class="title"><a name="id2567826"></a>Callsign</h3></div></div></div><p>
1069 This sets the callsign included in each telemetry packet. Set this
1070 as needed to conform to your local radio regulations.
1071 </p></div></div><div class="section" title="Configure AltosUI"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2567986"></a>Configure AltosUI</h2></div></div></div><p>
1072 This button presents a dialog so that you can configure the AltosUI global settings.
1073 </p><div class="section" title="Voice Settings"><div class="titlepage"><div><div><h3 class="title"><a name="id2554292"></a>Voice Settings</h3></div></div></div><p>
1074 AltosUI provides voice annoucements during flight so that you
1075 can keep your eyes on the sky and still get information about
1076 the current flight status. However, sometimes you don't want
1078 </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>
1079 Test Voice—Plays a short message allowing you to verify
1080 that the audio systme is working and the volume settings
1082 </p></li></ul></div></div><div class="section" title="Log Directory"><div class="titlepage"><div><div><h3 class="title"><a name="id2592599"></a>Log Directory</h3></div></div></div><p>
1083 AltosUI logs all telemetry data and saves all TeleMetrum flash
1084 data to this directory. This directory is also used as the
1085 staring point when selecting data files for display or export.
1087 Click on the directory name to bring up a directory choosing
1088 dialog, select a new directory and click 'Select Directory' to
1089 change where AltosUI reads and writes data files.
1090 </p></div><div class="section" title="Callsign"><div class="titlepage"><div><div><h3 class="title"><a name="id2559399"></a>Callsign</h3></div></div></div><p>
1091 This value is used in command packet mode and is transmitted
1092 in each packet sent from TeleDongle and received from
1093 TeleMetrum. It is not used in telemetry mode as that transmits
1094 packets only from TeleMetrum to TeleDongle. Configure this
1095 with the AltosUI operators callsign as needed to comply with
1096 your local radio regulations.
1097 </p></div></div><div class="section" title="Flash Image"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2579274"></a>Flash Image</h2></div></div></div><p>
1098 This reprograms any Altus Metrum device by using a TeleMetrum or
1099 TeleDongle as a programming dongle. Please read the directions
1100 for connecting the programming cable in the main TeleMetrum
1101 manual before reading these instructions.
1103 Once you have the programmer and target devices connected,
1104 push the 'Flash Image' button. That will present a dialog box
1105 listing all of the connected devices. Carefully select the
1106 programmer device, not the device to be programmed.
1108 Next, select the image to flash to the device. These are named
1109 with the product name and firmware version. The file selector
1110 will start in the directory containing the firmware included
1111 with the AltosUI package. Navigate to the directory containing
1112 the desired firmware if it isn't there.
1114 Next, a small dialog containing the device serial number and
1115 RF calibration values should appear. If these values are
1116 incorrect (possibly due to a corrupted image in the device),
1117 enter the correct values here.
1119 Finally, a dialog containing a progress bar will follow the
1120 programming process.
1122 When programming is complete, the target device will
1123 reboot. Note that if the target device is connected via USB, you
1124 will have to unplug it and then plug it back in for the USB
1125 connection to reset so that you can communicate with the device
1127 </p></div><div class="section" title="Fire Igniter"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2577046"></a>Fire Igniter</h2></div></div></div><p>
1128 This activates the igniter circuits in TeleMetrum to help test
1129 recovery systems deployment. Because this command can operate
1130 over the Packet Command Link, you can prepare the rocket as
1131 for flight and then test the recovery system without needing
1132 to snake wires inside the airframe.
1134 Selecting the 'Fire Igniter' button brings up the usual device
1135 selection dialog. Pick the desired TeleDongle or TeleMetrum
1136 device. This brings up another window which shows the current
1137 continutity test status for both apogee and main charges.
1139 Next, select the desired igniter to fire. This will enable the
1142 Select the 'Arm' button. This enables the 'Fire' button. The
1143 word 'Arm' is replaced by a countdown timer indicating that
1144 you have 10 seconds to press the 'Fire' button or the system
1145 will deactivate, at which point you start over again at
1146 selecting the desired igniter.
1147 </p></div></div><div class="chapter" title="Chapter 8. Using Altus Metrum Products"><div class="titlepage"><div><div><h2 class="title"><a name="id2587842"></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="#id2574948">Being Legal</a></span></dt><dd><dl><dt><span class="section"><a href="#id2561015">In the Rocket</a></span></dt><dt><span class="section"><a href="#id2575161">On the Ground</a></span></dt><dt><span class="section"><a href="#id2581564">Data Analysis</a></span></dt><dt><span class="section"><a href="#id2562286">Future Plans</a></span></dt></dl></dd></dl></div><div class="section" title="Being Legal"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2574948"></a>Being Legal</h2></div></div></div><p>
1148 First off, in the US, you need an <a class="ulink" href="http://www.altusmetrum.org/Radio/" target="_top">amateur radio license</a> or
1149 other authorization to legally operate the radio transmitters that are part
1151 </p><div class="section" title="In the Rocket"><div class="titlepage"><div><div><h3 class="title"><a name="id2561015"></a>In the Rocket</h3></div></div></div><p>
1152 In the rocket itself, you just need a <a class="ulink" href="http://www.altusmetrum.org/TeleMetrum/" target="_top">TeleMetrum</a> board and
1153 a LiPo rechargeable battery. An 860mAh battery weighs less than a 9V
1154 alkaline battery, and will run a <a class="ulink" href="http://www.altusmetrum.org/TeleMetrum/" target="_top">TeleMetrum</a> for hours.
1156 By default, we ship TeleMetrum with a simple wire antenna. If your
1157 electronics bay or the airframe it resides within is made of carbon fiber,
1158 which is opaque to RF signals, you may choose to have an SMA connector
1159 installed so that you can run a coaxial cable to an antenna mounted
1160 elsewhere in the rocket.
1161 </p></div><div class="section" title="On the Ground"><div class="titlepage"><div><div><h3 class="title"><a name="id2575161"></a>On the Ground</h3></div></div></div><p>
1162 To receive the data stream from the rocket, you need an antenna and short
1163 feedline connected to one of our <a class="ulink" href="http://www.altusmetrum.org/TeleDongle/" target="_top">TeleDongle</a> units. The
1164 TeleDongle in turn plugs directly into the USB port on a notebook
1165 computer. Because TeleDongle looks like a simple serial port, your computer
1166 does not require special device drivers... just plug it in.
1168 The GUI tool, AltosUI, is written in Java and runs across
1169 Linux, Mac OS and Windows. There's also a suite of C tools
1170 for Linux which can perform most of the same tasks.
1172 After the flight, you can use the RF link to extract the more detailed data
1173 logged in the rocket, or you can use a mini USB cable to plug into the
1174 TeleMetrum board directly. Pulling out the data without having to open up
1175 the rocket is pretty cool! A USB cable is also how you charge the LiPo
1176 battery, so you'll want one of those anyway... the same cable used by lots
1177 of digital cameras and other modern electronic stuff will work fine.
1179 If your rocket lands out of sight, you may enjoy having a hand-held GPS
1180 receiver, so that you can put in a waypoint for the last reported rocket
1181 position before touch-down. This makes looking for your rocket a lot like
1182 Geo-Cacheing... just go to the waypoint and look around starting from there.
1184 You may also enjoy having a ham radio "HT" that covers the 70cm band... you
1185 can use that with your antenna to direction-find the rocket on the ground
1186 the same way you can use a Walston or Beeline tracker. This can be handy
1187 if the rocket is hiding in sage brush or a tree, or if the last GPS position
1188 doesn't get you close enough because the rocket dropped into a canyon, or
1189 the wind is blowing it across a dry lake bed, or something like that... Keith
1190 and Bdale both currently own and use the Yaesu VX-7R at launches.
1192 So, to recap, on the ground the hardware you'll need includes:
1193 </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
1194 an antenna and feedline
1195 </li><li class="listitem">
1197 </li><li class="listitem">
1199 </li><li class="listitem">
1200 optionally, a handheld GPS receiver
1201 </li><li class="listitem">
1202 optionally, an HT or receiver covering 435 Mhz
1205 The best hand-held commercial directional antennas we've found for radio
1206 direction finding rockets are from
1207 <a class="ulink" href="http://www.arrowantennas.com/" target="_top">
1210 The 440-3 and 440-5 are both good choices for finding a
1211 TeleMetrum-equipped rocket when used with a suitable 70cm HT.
1212 </p></div><div class="section" title="Data Analysis"><div class="titlepage"><div><div><h3 class="title"><a name="id2581564"></a>Data Analysis</h3></div></div></div><p>
1213 Our software makes it easy to log the data from each flight, both the
1214 telemetry received over the RF link during the flight itself, and the more
1215 complete data log recorded in the DataFlash memory on the TeleMetrum
1216 board. Once this data is on your computer, our postflight tools make it
1217 easy to quickly get to the numbers everyone wants, like apogee altitude,
1218 max acceleration, and max velocity. You can also generate and view a
1219 standard set of plots showing the altitude, acceleration, and
1220 velocity of the rocket during flight. And you can even export a data file
1221 useable with Google Maps and Google Earth for visualizing the flight path
1222 in two or three dimensions!
1224 Our ultimate goal is to emit a set of files for each flight that can be
1225 published as a web page per flight, or just viewed on your local disk with
1227 </p></div><div class="section" title="Future Plans"><div class="titlepage"><div><div><h3 class="title"><a name="id2562286"></a>Future Plans</h3></div></div></div><p>
1228 In the future, we intend to offer "companion boards" for the rocket that will
1229 plug in to TeleMetrum to collect additional data, provide more pyro channels,
1230 and so forth. A reference design for a companion board will be documented
1231 soon, and will be compatible with open source Arduino programming tools.
1233 We are also working on the design of a hand-held ground terminal that will
1234 allow monitoring the rocket's status, collecting data during flight, and
1235 logging data after flight without the need for a notebook computer on the
1236 flight line. Particularly since it is so difficult to read most notebook
1237 screens in direct sunlight, we think this will be a great thing to have.
1239 Because all of our work is open, both the hardware designs and the software,
1240 if you have some great idea for an addition to the current Altus Metrum family,
1241 feel free to dive in and help! Or let us know what you'd like to see that
1242 we aren't already working on, and maybe we'll get excited about it too...
1243 </p></div></div></div></div></body></html>
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