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="id2360926"></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="id2636425"></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</td><td align="left">18 January 2011</td></tr><tr><td align="left" colspan="2">
8 Updated for software version 0.9. Note that 0.9 represents a
9 telemetry format change, meaning both ends of a link (TeleMetrum and
10 TeleDongle) must be updated or communications will fail.
11 </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="id2628351"></a>Acknowledgements</h2></div></div></div>
13 Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing "The
14 Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter
15 Kit" which has turned into the Getting Started chapter in this
16 book. Bob was one of our first customers for a production
17 TeleMetrum, and the enthusiasm that led to his contribution of
18 this section is immensely gratifying and highy appreciated!
21 And thanks to Anthony (AJ) Towns for contributing the
22 AltosUI graphing and site map code and documentation. Free
23 software means that our customers and friends can become our
24 collaborators, and we certainly appreciate this level of
28 Have fun using these products, and we hope to meet all of you
29 out on the rocket flight line somewhere.
30 </p><div class="literallayout"><p><br>
31 Bdale Garbee, KB0G<br>
32 NAR #87103, TRA #12201<br>
34 Keith Packard, KD7SQG<br>
35 NAR #88757, TRA #12200<br>
38 </div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="chapter"><a href="#id2605461">1. Introduction and Overview</a></span></dt><dt><span class="chapter"><a href="#id2605503">2. Getting Started</a></span></dt><dd><dl><dt><span class="section"><a href="#id2644514">FAQ</a></span></dt></dl></dd><dt><span class="chapter"><a href="#id2631620">3. Specifications</a></span></dt><dt><span class="chapter"><a href="#id2659474">4. Handling Precautions</a></span></dt><dt><span class="chapter"><a href="#id2631852">5. Hardware Overview</a></span></dt><dt><span class="chapter"><a href="#id2637717">6. System Operation</a></span></dt><dd><dl><dt><span class="section"><a href="#id2640865">Firmware Modes </a></span></dt><dt><span class="section"><a href="#id2642576">GPS </a></span></dt><dt><span class="section"><a href="#id2656980">Ground Testing </a></span></dt><dt><span class="section"><a href="#id2656978">Radio Link </a></span></dt><dt><span class="section"><a href="#id2627699">Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#id2647970">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2638884">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2656690">Main Deployment Altitude</a></span></dt></dl></dd><dt><span class="section"><a href="#id2635319">Calibration</a></span></dt><dd><dl><dt><span class="section"><a href="#id2659041">Radio Frequency</a></span></dt><dt><span class="section"><a href="#id2649152">Accelerometer</a></span></dt></dl></dd><dt><span class="section"><a href="#id2657390">Updating Device Firmware</a></span></dt><dd><dl><dt><span class="section"><a href="#id2630289">Updating TeleMetrum Firmware</a></span></dt><dt><span class="section"><a href="#id2639681">Updating TeleDongle Firmware</a></span></dt></dl></dd></dl></dd><dt><span class="chapter"><a href="#id2637633">7. AltosUI</a></span></dt><dd><dl><dt><span class="section"><a href="#id2654003">Packet Command Mode</a></span></dt><dt><span class="section"><a href="#id2647872">Monitor Flight</a></span></dt><dd><dl><dt><span class="section"><a href="#id2630489">Launch Pad</a></span></dt><dt><span class="section"><a href="#id2650566">Ascent</a></span></dt><dt><span class="section"><a href="#id2651780">Descent</a></span></dt><dt><span class="section"><a href="#id2637083">Landed</a></span></dt><dt><span class="section"><a href="#id2662597">Site Map</a></span></dt></dl></dd><dt><span class="section"><a href="#id2652017">Save Flight Data</a></span></dt><dt><span class="section"><a href="#id2662100">Replay Flight</a></span></dt><dt><span class="section"><a href="#id2648922">Graph Data</a></span></dt><dt><span class="section"><a href="#id2643923">Export Data</a></span></dt><dd><dl><dt><span class="section"><a href="#id2651125">Comma Separated Value Format</a></span></dt><dt><span class="section"><a href="#id2654686">Keyhole Markup Language (for Google Earth)</a></span></dt></dl></dd><dt><span class="section"><a href="#id2645946">Configure TeleMetrum</a></span></dt><dd><dl><dt><span class="section"><a href="#id2634804">Main Deploy Altitude</a></span></dt><dt><span class="section"><a href="#id2628486">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2657936">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2639511">Radio Calibration</a></span></dt><dt><span class="section"><a href="#id2637390">Callsign</a></span></dt><dt><span class="section"><a href="#id2648042">Maximum Flight Log Size</a></span></dt></dl></dd><dt><span class="section"><a href="#id2639748">Configure AltosUI</a></span></dt><dd><dl><dt><span class="section"><a href="#id2651032">Voice Settings</a></span></dt><dt><span class="section"><a href="#id2649086">Log Directory</a></span></dt><dt><span class="section"><a href="#id2640668">Callsign</a></span></dt><dt><span class="section"><a href="#id2621966">Serial Debug</a></span></dt></dl></dd><dt><span class="section"><a href="#id2651293">Flash Image</a></span></dt><dt><span class="section"><a href="#id2651858">Fire Igniter</a></span></dt></dl></dd><dt><span class="chapter"><a href="#id2646109">8. Using Altus Metrum Products</a></span></dt><dd><dl><dt><span class="section"><a href="#id2651706">Being Legal</a></span></dt><dt><span class="section"><a href="#id2649421">In the Rocket</a></span></dt><dt><span class="section"><a href="#id2648265">On the Ground</a></span></dt><dt><span class="section"><a href="#id2654896">Data Analysis</a></span></dt><dt><span class="section"><a href="#id2661470">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="id2605461"></a>Chapter 1. Introduction and Overview</h2></div></div></div><p>
39 Welcome to the Altus Metrum community! Our circuits and software reflect
40 our passion for both hobby rocketry and Free Software. We hope their
41 capabilities and performance will delight you in every way, but by
42 releasing all of our hardware and software designs under open licenses,
43 we also hope to empower you to take as active a role in our collective
46 The focal point of our community is TeleMetrum, a dual deploy altimeter
47 with fully integrated GPS and radio telemetry as standard features, and
48 a "companion interface" that will support optional capabilities in the
51 Complementing TeleMetrum is TeleDongle, a USB to RF interface for
52 communicating with TeleMetrum. Combined with your choice of antenna and
53 notebook computer, TeleDongle and our associated user interface software
54 form a complete ground station capable of logging and displaying in-flight
55 telemetry, aiding rocket recovery, then processing and archiving flight
56 data for analysis and review.
58 More products will be added to the Altus Metrum family over time, and
59 we currently envision that this will be a single, comprehensive manual
60 for the entire product family.
61 </p></div><div class="chapter" title="Chapter 2. Getting Started"><div class="titlepage"><div><div><h2 class="title"><a name="id2605503"></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="#id2644514">FAQ</a></span></dt></dl></div><p>
62 The first thing to do after you check the inventory of parts in your
63 "starter kit" is to charge the battery by plugging it into the
64 corresponding socket of the TeleMetrum and then using the USB A to
66 cable to plug the Telemetrum into your computer's USB socket. The
67 TeleMetrum circuitry will charge the battery whenever it is plugged
68 in, because the TeleMetrum's on-off switch does NOT control the
69 charging circuitry. When the GPS chip is initially searching for
70 satellites, TeleMetrum will consume more current than it can pull
71 from the usb port, so the battery must be attached in order to get
72 satellite lock. Once GPS is locked, the current consumption goes back
73 down enough to enable charging while
74 running. So it's a good idea to fully charge the battery as your
75 first item of business so there is no issue getting and maintaining
76 satellite lock. The yellow charge indicator led will go out when the
77 battery is nearly full and the charger goes to trickle charge. It
78 can take several hours to fully recharge a deeply discharged battery.
80 The other active device in the starter kit is the TeleDongle USB to
81 RF interface. If you plug it in to your Mac or Linux computer it should
82 "just work", showing up as a serial port device. Windows systems need
83 driver information that is part of the AltOS download to know that the
84 existing USB modem driver will work. If you are using Linux and are
85 having problems, try moving to a fresher kernel (2.6.33 or newer), as
86 the USB serial driver had ugly bugs in some earlier versions.
88 Next you should obtain and install the AltOS utilities. These include
89 the AltosUI ground station program, current firmware images for
90 TeleMetrum and TeleDongle, and a number of standalone utilities that
91 are rarely needed. Pre-built binary packages are available for Debian
92 Linux, Microsoft Windows, and recent MacOSX versions. Full sourcecode
93 and build instructions for some other Linux variants are also available.
94 The latest version may always be downloaded from
95 <a class="ulink" href="http://altusmetrum.org/AltOS" target="_top">http://altusmetrum.org/AltOS</a>.
97 Both Telemetrum and TeleDongle can be directly communicated
98 with using USB ports. The first thing you should try after getting
99 both units plugged into to your computer's usb port(s) is to run
100 'ao-list' from a terminal-window to see what port-device-name each
101 device has been assigned by the operating system.
102 You will need this information to access the devices via their
103 respective on-board firmware and data using other command line
104 programs in the AltOS software suite.
106 To access the device's firmware for configuration you need a terminal
107 program such as you would use to talk to a modem. The software
108 authors prefer using the program 'cu' which comes from the UUCP package
109 on most Unix-like systems such as Linux. An example command line for
110 cu might be 'cu -l /dev/ttyACM0', substituting the correct number
111 indicated from running the
112 ao-list program. Another reasonable terminal program for Linux is
113 'cutecom'. The default 'escape'
114 character used by CU (i.e. the character you use to
115 issue commands to cu itself instead of sending the command as input
116 to the connected device) is a '~'. You will need this for use in
117 only two different ways during normal operations. First is to exit
118 the program by sending a '~.' which is called a 'escape-disconnect'
119 and allows you to close-out from 'cu'. The
120 second use will be outlined later.
122 Both TeleMetrum and TeleDongle share the concept of a two level
123 command set in their firmware.
124 The first layer has several single letter commands. Once
125 you are using 'cu' (or 'cutecom') sending (typing) a '?'
126 returns a full list of these
127 commands. The second level are configuration sub-commands accessed
128 using the 'c' command, for
129 instance typing 'c?' will give you this second level of commands
130 (all of which require the
131 letter 'c' to access). Please note that most configuration options
132 are stored only in DataFlash memory, and only TeleMetrum has this
133 memory to save the various values entered like the channel number
134 and your callsign when powered off. TeleDongle requires that you
135 set these each time you plug it in, which ao-view can help with.
137 Try setting these config ('c' or second level menu) values. A good
138 place to start is by setting your call sign. By default, the boards
139 use 'N0CALL' which is cute, but not exactly legal!
140 Spend a few minutes getting comfortable with the units, their
141 firmware, and 'cu' (or possibly 'cutecom').
142 For instance, try to send
143 (type) a 'c r 2' and verify the channel change by sending a 'c s'.
144 Verify you can connect and disconnect from the units while in your
145 terminal program by sending the escape-disconnect mentioned above.
147 Note that the 'reboot' command, which is very useful on TeleMetrum,
148 will likely just cause problems with the dongle. The *correct* way
149 to reset the dongle is just to unplug and re-plug it.
151 A fun thing to do at the launch site and something you can do while
152 learning how to use these units is to play with the rf-link access
153 of the TeleMetrum from the TeleDongle. Be aware that you *must* create
154 some physical separation between the devices, otherwise the link will
155 not function due to signal overload in the receivers in each device.
157 Now might be a good time to take a break and read the rest of this
158 manual, particularly about the two "modes" that the TeleMetrum
159 can be placed in and how the position of the TeleMetrum when booting
160 up will determine whether the unit is in "pad" or "idle" mode.
162 You can access a TeleMetrum in idle mode from the Teledongle's USB
163 connection using the rf link
164 by issuing a 'p' command to the TeleDongle. Practice connecting and
165 disconnecting ('~~' while using 'cu') from the TeleMetrum. If
166 you cannot escape out of the "p" command, (by using a '~~' when in
167 CU) then it is likely that your kernel has issues. Try a newer version.
169 Using this rf link allows you to configure the TeleMetrum, test
170 fire e-matches and igniters from the flight line, check pyro-match
171 continuity and so forth. You can leave the unit turned on while it
172 is in 'idle mode' and then place the
173 rocket vertically on the launch pad, walk away and then issue a
174 reboot command. The TeleMetrum will reboot and start sending data
175 having changed to the "pad" mode. If the TeleDongle is not receiving
176 this data, you can disconnect 'cu' from the Teledongle using the
177 procedures mentioned above and THEN connect to the TeleDongle from
178 inside 'ao-view'. If this doesn't work, disconnect from the
179 TeleDongle, unplug it, and try again after plugging it back in.
181 Eventually the GPS will find enough satellites, lock in on them,
182 and 'ao-view' will both auditorially announce and visually indicate
184 Now you can launch knowing that you have a good data path and
185 good satellite lock for flight data and recovery. Remember
186 you MUST tell ao-view to connect to the TeleDongle explicitly in
187 order for ao-view to be able to receive data.
189 Both RDF (radio direction finding) tones from the TeleMetrum and
190 GPS trekking data are available and together are very useful in
191 locating the rocket once it has landed. (The last good GPS data
192 received before touch-down will be on the data screen of 'ao-view'.)
194 Once you have recovered the rocket you can download the eeprom
195 contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over
196 either a USB cable or over the radio link using TeleDongle.
197 And by following the man page for 'ao-postflight' you can create
198 various data output reports, graphs, and even kml data to see the
199 flight trajectory in google-earth. (Moving the viewing angle making
200 sure to connect the yellow lines while in google-earth is the proper
203 As for ao-view.... some things are in the menu but don't do anything
204 very useful. The developers have stopped working on ao-view to focus
205 on a new, cross-platform ground station program. So ao-view may or
206 may not be updated in the future. Mostly you just use
207 the Log and Device menus. It has a wonderful display of the incoming
208 flight data and I am sure you will enjoy what it has to say to you
209 once you enable the voice output!
210 </p><div class="section" title="FAQ"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2644514"></a>FAQ</h2></div></div></div><p>
211 The altimeter (TeleMetrum) seems to shut off when disconnected from the
212 computer. Make sure the battery is adequately charged. Remember the
213 unit will pull more power than the USB port can deliver before the
214 GPS enters "locked" mode. The battery charges best when TeleMetrum
217 It's impossible to stop the TeleDongle when it's in "p" mode, I have
218 to unplug the USB cable? Make sure you have tried to "escape out" of
219 this mode. If this doesn't work the reboot procedure for the
220 TeleDongle *is* to simply unplug it. 'cu' however will retain it's
221 outgoing buffer IF your "escape out" ('~~') does not work.
222 At this point using either 'ao-view' (or possibly
223 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
226 The amber LED (on the TeleMetrum/altimeter) lights up when both
227 battery and USB are connected. Does this mean it's charging?
228 Yes, the yellow LED indicates the charging at the 'regular' rate.
229 If the led is out but the unit is still plugged into a USB port,
230 then the battery is being charged at a 'trickle' rate.
232 There are no "dit-dah-dah-dit" sound like the manual mentions?
233 That's the "pad" mode. Weak batteries might be the problem.
234 It is also possible that the unit is horizontal and the output
235 is instead a "dit-dit" meaning 'idle'.
237 It's unclear how to use 'ao-view' and other programs when 'cu'
238 is running. You cannot have more than one program connected to
239 the TeleDongle at one time without apparent data loss as the
240 incoming data will not make it to both programs intact.
241 Disconnect whatever programs aren't currently being used.
243 How do I save flight data?
244 Live telemetry is written to file(s) whenever 'ao-view' is connected
245 to the TeleDongle. The file area defaults to ~/altos
246 but is easily changed using the menus in 'ao-view'. The files that
247 are written end in '.telem'. The after-flight
248 data-dumped files will end in .eeprom and represent continuous data
249 unlike the rf-linked .telem files that are subject to the
250 turnarounds/data-packaging time slots in the half-duplex rf data path.
251 See the above instructions on what and how to save the eeprom stored
252 data after physically retrieving your TeleMetrum. Make sure to save
253 the on-board data after each flight, as the current firmware will
254 over-write any previous flight data during a new flight.
255 </p></div></div><div class="chapter" title="Chapter 3. Specifications"><div class="titlepage"><div><div><h2 class="title"><a name="id2631620"></a>Chapter 3. Specifications</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
256 Recording altimeter for model rocketry.
257 </p></li><li class="listitem"><p>
258 Supports dual deployment (can fire 2 ejection charges).
259 </p></li><li class="listitem"><p>
260 70cm ham-band transceiver for telemetry downlink.
261 </p></li><li class="listitem"><p>
262 Barometric pressure sensor good to 45k feet MSL.
263 </p></li><li class="listitem"><p>
264 1-axis high-g accelerometer for motor characterization, capable of
265 +/- 50g using default part.
266 </p></li><li class="listitem"><p>
267 On-board, integrated GPS receiver with 5hz update rate capability.
268 </p></li><li class="listitem"><p>
269 On-board 1 megabyte non-volatile memory for flight data storage.
270 </p></li><li class="listitem"><p>
271 USB interface for battery charging, configuration, and data recovery.
272 </p></li><li class="listitem"><p>
273 Fully integrated support for LiPo rechargeable batteries.
274 </p></li><li class="listitem"><p>
275 Uses LiPo to fire e-matches, can be modiied to support
276 optional separate pyro battery if needed.
277 </p></li><li class="listitem"><p>
278 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube.
279 </p></li></ul></div></div><div class="chapter" title="Chapter 4. Handling Precautions"><div class="titlepage"><div><div><h2 class="title"><a name="id2659474"></a>Chapter 4. Handling Precautions</h2></div></div></div><p>
280 TeleMetrum is a sophisticated electronic device. When handled gently and
281 properly installed in an airframe, it will deliver impressive results.
282 However, like all electronic devices, there are some precautions you
285 The Lithium Polymer rechargeable batteries used with TeleMetrum have an
286 extraordinary power density. This is great because we can fly with
287 much less battery mass than if we used alkaline batteries or previous
288 generation rechargeable batteries... but if they are punctured
289 or their leads are allowed to short, they can and will release their
291 Thus we recommend that you take some care when handling our batteries
292 and consider giving them some extra protection in your airframe. We
293 often wrap them in suitable scraps of closed-cell packing foam before
294 strapping them down, for example.
296 The TeleMetrum barometric sensor is sensitive to sunlight. In normal
297 mounting situations, it and all of the other surface mount components
298 are "down" towards whatever the underlying mounting surface is, so
299 this is not normally a problem. Please consider this, though, when
300 designing an installation, for example, in a 29mm airframe with a
301 see-through plastic payload bay.
303 The TeleMetrum barometric sensor sampling port must be able to
305 both by not being covered by foam or tape or other materials that might
306 directly block the hole on the top of the sensor, but also by having a
307 suitable static vent to outside air.
309 As with all other rocketry electronics, TeleMetrum must be protected
310 from exposure to corrosive motor exhaust and ejection charge gasses.
311 </p></div><div class="chapter" title="Chapter 5. Hardware Overview"><div class="titlepage"><div><div><h2 class="title"><a name="id2631852"></a>Chapter 5. Hardware Overview</h2></div></div></div><p>
312 TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to
313 fit inside coupler for 29mm airframe tubing, but using it in a tube that
314 small in diameter may require some creativity in mounting and wiring
315 to succeed! The default 1/4
316 wave UHF wire antenna attached to the center of the nose-cone end of
317 the board is about 7 inches long, and wiring for a power switch and
318 the e-matches for apogee and main ejection charges depart from the
319 fin can end of the board. Given all this, an ideal "simple" avionics
320 bay for TeleMetrum should have at least 10 inches of interior length.
322 A typical TeleMetrum installation using the on-board GPS antenna and
323 default wire UHF antenna involves attaching only a suitable
324 Lithium Polymer battery, a single pole switch for power on/off, and
325 two pairs of wires connecting e-matches for the apogee and main ejection
328 By default, we use the unregulated output of the LiPo battery directly
329 to fire ejection charges. This works marvelously with standard
330 low-current e-matches like the J-Tek from MJG Technologies, and with
331 Quest Q2G2 igniters. However, if you
332 want or need to use a separate pyro battery, the board can be factory
333 modified to do so. This involves cutting two traces and adding a jumper
334 in a densely populated part of the board on TeleMetrum v1.0 and v1.1,
335 along with installation of a pyro battery connector at location B2.
337 We offer two choices of pyro and power switch connector, or you can
338 choose neither and solder wires directly to the board. All three choices
339 are reasonable depending on the constraints of your airframe. Our
340 favorite option when there is sufficient room above the board is to use
341 the Tyco pin header with polarization and locking. If you choose this
342 option, you crimp individual wires for the power switch and e-matches
343 into a mating connector, and installing and removing the TeleMetrum
344 board from an airframe is as easy as plugging or unplugging two
345 connectors. If the airframe will not support this much height or if
346 you want to be able to directly attach e-match leads to the board, we
347 offer a screw terminal block. This is very similar to what most other
348 altimeter vendors provide and so may be the most familiar option.
349 You'll need a very small straight blade screwdriver to connect
350 and disconnect the board in this case, such as you might find in a
351 jeweler's screwdriver set. Finally, you can forego both options and
352 solder wires directly to the board, which may be the best choice for
353 minimum diameter and/or minimum mass designs.
355 For most airframes, the integrated GPS antenna and wire UHF antenna are
356 a great combination. However, if you are installing in a carbon-fiber
357 electronics bay which is opaque to RF signals, you may need to use
358 off-board external antennas instead. In this case, you can order
359 TeleMetrum with an SMA connector for the UHF antenna connection, and
360 you can unplug the integrated GPS antenna and select an appropriate
361 off-board GPS antenna with cable terminating in a U.FL connector.
362 </p></div><div class="chapter" title="Chapter 6. System Operation"><div class="titlepage"><div><div><h2 class="title"><a name="id2637717"></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="#id2640865">Firmware Modes </a></span></dt><dt><span class="section"><a href="#id2642576">GPS </a></span></dt><dt><span class="section"><a href="#id2656980">Ground Testing </a></span></dt><dt><span class="section"><a href="#id2656978">Radio Link </a></span></dt><dt><span class="section"><a href="#id2627699">Configurable Parameters</a></span></dt><dd><dl><dt><span class="section"><a href="#id2647970">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2638884">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2656690">Main Deployment Altitude</a></span></dt></dl></dd><dt><span class="section"><a href="#id2635319">Calibration</a></span></dt><dd><dl><dt><span class="section"><a href="#id2659041">Radio Frequency</a></span></dt><dt><span class="section"><a href="#id2649152">Accelerometer</a></span></dt></dl></dd><dt><span class="section"><a href="#id2657390">Updating Device Firmware</a></span></dt><dd><dl><dt><span class="section"><a href="#id2630289">Updating TeleMetrum Firmware</a></span></dt><dt><span class="section"><a href="#id2639681">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="id2640865"></a>Firmware Modes </h2></div></div></div><p>
363 The AltOS firmware build for TeleMetrum has two fundamental modes,
364 "idle" and "flight". Which of these modes the firmware operates in
365 is determined by the orientation of the rocket (well, actually the
366 board, of course...) at the time power is switched on. If the rocket
367 is "nose up", then TeleMetrum assumes it's on a rail or rod being
368 prepared for launch, so the firmware chooses flight mode. However,
369 if the rocket is more or less horizontal, the firmware instead enters
372 At power on, you will hear three beeps
373 ("S" in Morse code for startup) and then a pause while
374 TeleMetrum completes initialization and self tests, and decides which
377 In flight or "pad" mode, TeleMetrum turns on the GPS system,
379 state machine, goes into transmit-only mode on the RF link sending
380 telemetry, and waits for launch to be detected. Flight mode is
381 indicated by an audible "di-dah-dah-dit" ("P" for pad) on the
383 beeps indicating the state of the pyrotechnic igniter continuity.
384 One beep indicates apogee continuity, two beeps indicate
385 main continuity, three beeps indicate both apogee and main continuity,
386 and one longer "brap" sound indicates no continuity. For a dual
387 deploy flight, make sure you're getting three beeps before launching!
388 For apogee-only or motor eject flights, do what makes sense.
390 In idle mode, you will hear an audible "di-dit" ("I" for idle), and
391 the normal flight state machine is disengaged, thus
392 no ejection charges will fire. TeleMetrum also listens on the RF
393 link when in idle mode for packet mode requests sent from TeleDongle.
394 Commands can be issued to a TeleMetrum in idle mode over either
395 USB or the RF link equivalently.
396 Idle mode is useful for configuring TeleMetrum, for extracting data
397 from the on-board storage chip after flight, and for ground testing
400 One "neat trick" of particular value when TeleMetrum is used with very
401 large airframes, is that you can power the board up while the rocket
402 is horizontal, such that it comes up in idle mode. Then you can
403 raise the airframe to launch position, use a TeleDongle to open
404 a packet connection, and issue a 'reset' command which will cause
405 TeleMetrum to reboot, realize it's now nose-up, and thus choose
406 flight mode. This is much safer than standing on the top step of a
407 rickety step-ladder or hanging off the side of a launch tower with
408 a screw-driver trying to turn on your avionics before installing
410 </p></div><div class="section" title="GPS"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2642576"></a>GPS </h2></div></div></div><p>
411 TeleMetrum includes a complete GPS receiver. See a later section for
412 a brief explanation of how GPS works that will help you understand
413 the information in the telemetry stream. The bottom line is that
414 the TeleMetrum GPS receiver needs to lock onto at least four
415 satellites to obtain a solid 3 dimensional position fix and know
418 TeleMetrum provides backup power to the GPS chip any time a LiPo
419 battery is connected. This allows the receiver to "warm start" on
420 the launch rail much faster than if every power-on were a "cold start"
421 for the GPS receiver. In typical operations, powering up TeleMetrum
422 on the flight line in idle mode while performing final airframe
423 preparation will be sufficient to allow the GPS receiver to cold
424 start and acquire lock. Then the board can be powered down during
425 RSO review and installation on a launch rod or rail. When the board
426 is turned back on, the GPS system should lock very quickly, typically
427 long before igniter installation and return to the flight line are
429 </p></div><div class="section" title="Ground Testing"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2656980"></a>Ground Testing </h2></div></div></div><p>
430 An important aspect of preparing a rocket using electronic deployment
431 for flight is ground testing the recovery system. Thanks
432 to the bi-directional RF link central to the Altus Metrum system,
433 this can be accomplished in a TeleMetrum-equipped rocket without as
434 much work as you may be accustomed to with other systems. It can
437 Just prep the rocket for flight, then power up TeleMetrum while the
438 airframe is horizontal. This will cause the firmware to go into
439 "idle" mode, in which the normal flight state machine is disabled and
440 charges will not fire without manual command. Then, establish an
441 RF packet connection from a TeleDongle-equipped computer using the
442 P command from a safe distance. You can now command TeleMetrum to
443 fire the apogee or main charges to complete your testing.
445 In order to reduce the chance of accidental firing of pyrotechnic
446 charges, the command to fire a charge is intentionally somewhat
447 difficult to type, and the built-in help is slightly cryptic to
448 prevent accidental echoing of characters from the help text back at
449 the board from firing a charge. The command to fire the apogee
450 drogue charge is 'i DoIt drogue' and the command to fire the main
451 charge is 'i DoIt main'.
452 </p></div><div class="section" title="Radio Link"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2656978"></a>Radio Link </h2></div></div></div><p>
453 The chip our boards are based on incorporates an RF transceiver, but
454 it's not a full duplex system... each end can only be transmitting or
455 receiving at any given moment. So we had to decide how to manage the
458 By design, TeleMetrum firmware listens for an RF connection when
459 it's in "idle mode" (turned on while the rocket is horizontal), which
460 allows us to use the RF link to configure the rocket, do things like
461 ejection tests, and extract data after a flight without having to
462 crack open the airframe. However, when the board is in "flight
463 mode" (turned on when the rocket is vertical) the TeleMetrum only
464 transmits and doesn't listen at all. That's because we want to put
465 ultimate priority on event detection and getting telemetry out of
466 the rocket and out over
467 the RF link in case the rocket crashes and we aren't able to extract
470 We don't use a 'normal packet radio' mode because they're just too
471 inefficient. The GFSK modulation we use is just FSK with the
472 baseband pulses passed through a
473 Gaussian filter before they go into the modulator to limit the
474 transmitted bandwidth. When combined with the hardware forward error
475 correction support in the cc1111 chip, this allows us to have a very
476 robust 38.4 kilobit data link with only 10 milliwatts of transmit power,
477 a whip antenna in the rocket, and a hand-held Yagi on the ground. We've
478 had flights to above 21k feet AGL with good reception, and calculations
479 suggest we should be good to well over 40k feet AGL with a 5-element yagi on
480 the ground. We hope to fly boards to higher altitudes soon, and would
481 of course appreciate customer feedback on performance in higher
483 </p></div><div class="section" title="Configurable Parameters"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2627699"></a>Configurable Parameters</h2></div></div></div><p>
484 Configuring a TeleMetrum board for flight is very simple. Because we
485 have both acceleration and pressure sensors, there is no need to set
486 a "mach delay", for example. The few configurable parameters can all
487 be set using a simple terminal program over the USB port or RF link
489 </p><div class="section" title="Radio Channel"><div class="titlepage"><div><div><h3 class="title"><a name="id2647970"></a>Radio Channel</h3></div></div></div><p>
490 Our firmware supports 10 channels. The default channel 0 corresponds
491 to a center frequency of 434.550 Mhz, and channels are spaced every
492 100 khz. Thus, channel 1 is 434.650 Mhz, and channel 9 is 435.550 Mhz.
493 At any given launch, we highly recommend coordinating who will use
494 each channel and when to avoid interference. And of course, both
495 TeleMetrum and TeleDongle must be configured to the same channel to
496 successfully communicate with each other.
498 To set the radio channel, use the 'c r' command, like 'c r 3' to set
500 As with all 'c' sub-commands, follow this with a 'c w' to write the
501 change to the parameter block in the on-board DataFlash chip on
502 your TeleMetrum board if you want the change to stay in place across reboots.
503 </p></div><div class="section" title="Apogee Delay"><div class="titlepage"><div><div><h3 class="title"><a name="id2638884"></a>Apogee Delay</h3></div></div></div><p>
504 Apogee delay is the number of seconds after TeleMetrum detects flight
505 apogee that the drogue charge should be fired. In most cases, this
506 should be left at the default of 0. However, if you are flying
507 redundant electronics such as for an L3 certification, you may wish
508 to set one of your altimeters to a positive delay so that both
509 primary and backup pyrotechnic charges do not fire simultaneously.
511 To set the apogee delay, use the 'c d' command.
512 As with all 'c' sub-commands, follow this with a 'c w' to write the
513 change to the parameter block in the on-board DataFlash chip.
515 Please note that the TeleMetrum apogee detection algorithm always
516 fires a fraction of a second *after* apogee. If you are also flying
517 an altimeter like the PerfectFlite MAWD, which only supports selecting
518 0 or 1 seconds of apogee delay, you may wish to set the MAWD to 0
519 seconds delay and set the TeleMetrum to fire your backup 2 or 3
520 seconds later to avoid any chance of both charges firing
521 simultaneously. We've flown several airframes this way quite happily,
522 including Keith's successful L3 cert.
523 </p></div><div class="section" title="Main Deployment Altitude"><div class="titlepage"><div><div><h3 class="title"><a name="id2656690"></a>Main Deployment Altitude</h3></div></div></div><p>
524 By default, TeleMetrum will fire the main deployment charge at an
525 elevation of 250 meters (about 820 feet) above ground. We think this
526 is a good elevation for most airframes, but feel free to change this
527 to suit. In particular, if you are flying two altimeters, you may
529 deployment elevation for the backup altimeter to be something lower
530 than the primary so that both pyrotechnic charges don't fire
533 To set the main deployment altitude, use the 'c m' command.
534 As with all 'c' sub-commands, follow this with a 'c w' to write the
535 change to the parameter block in the on-board DataFlash chip.
536 </p></div></div><div class="section" title="Calibration"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2635319"></a>Calibration</h2></div></div></div><p>
537 There are only two calibrations required for a TeleMetrum board, and
538 only one for TeleDongle.
539 </p><div class="section" title="Radio Frequency"><div class="titlepage"><div><div><h3 class="title"><a name="id2659041"></a>Radio Frequency</h3></div></div></div><p>
540 The radio frequency is synthesized from a clock based on the 48 Mhz
541 crystal on the board. The actual frequency of this oscillator must be
542 measured to generate a calibration constant. While our GFSK modulation
543 bandwidth is wide enough to allow boards to communicate even when
544 their oscillators are not on exactly the same frequency, performance
545 is best when they are closely matched.
546 Radio frequency calibration requires a calibrated frequency counter.
547 Fortunately, once set, the variation in frequency due to aging and
548 temperature changes is small enough that re-calibration by customers
549 should generally not be required.
551 To calibrate the radio frequency, connect the UHF antenna port to a
552 frequency counter, set the board to channel 0, and use the 'C'
553 command to generate a CW carrier. Wait for the transmitter temperature
554 to stabilize and the frequency to settle down.
555 Then, divide 434.550 Mhz by the
556 measured frequency and multiply by the current radio cal value show
557 in the 'c s' command. For an unprogrammed board, the default value
558 is 1186611. Take the resulting integer and program it using the 'c f'
559 command. Testing with the 'C' command again should show a carrier
560 within a few tens of Hertz of the intended frequency.
561 As with all 'c' sub-commands, follow this with a 'c w' to write the
562 change to the parameter block in the on-board DataFlash chip.
563 </p></div><div class="section" title="Accelerometer"><div class="titlepage"><div><div><h3 class="title"><a name="id2649152"></a>Accelerometer</h3></div></div></div><p>
564 The accelerometer we use has its own 5 volt power supply and
565 the output must be passed through a resistive voltage divider to match
566 the input of our 3.3 volt ADC. This means that unlike the barometric
567 sensor, the output of the acceleration sensor is not ratiometric to
568 the ADC converter, and calibration is required. We also support the
569 use of any of several accelerometers from a Freescale family that
570 includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity,
571 a simple 2-point calibration yields acceptable results capturing both
572 the different sensitivities and ranges of the different accelerometer
573 parts and any variation in power supply voltages or resistor values
574 in the divider network.
576 To calibrate the acceleration sensor, use the 'c a 0' command. You
577 will be prompted to orient the board vertically with the UHF antenna
578 up and press a key, then to orient the board vertically with the
579 UHF antenna down and press a key.
580 As with all 'c' sub-commands, follow this with a 'c w' to write the
581 change to the parameter block in the on-board DataFlash chip.
583 The +1g and -1g calibration points are included in each telemetry
584 frame and are part of the header extracted by ao-dumplog after flight.
585 Note that we always store and return raw ADC samples for each
586 sensor... nothing is permanently "lost" or "damaged" if the
589 In the unlikely event an accel cal that goes badly, it is possible
590 that TeleMetrum may always come up in 'pad mode' and as such not be
591 listening to either the USB or radio interfaces. If that happens,
592 there is a special hook in the firmware to force the board back
593 in to 'idle mode' so you can re-do the cal. To use this hook, you
594 just need to ground the SPI clock pin at power-on. This pin is
595 available as pin 2 on the 8-pin companion connector, and pin 1 is
596 ground. So either carefully install a fine-gauge wire jumper
597 between the two pins closest to the index hole end of the 8-pin
598 connector, or plug in the programming cable to the 8-pin connector
599 and use a small screwdriver or similar to short the two pins closest
600 to the index post on the 4-pin end of the programming cable, and
601 power up the board. It should come up in 'idle mode' (two beeps).
602 </p></div></div><div class="section" title="Updating Device Firmware"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2657390"></a>Updating Device Firmware</h2></div></div></div><p>
603 The big conceptual thing to realize is that you have to use a
604 TeleDongle as a programmer to update a TeleMetrum, and vice versa.
605 Due to limited memory resources in the cc1111, we don't support
606 programming either unit directly over USB.
608 You may wish to begin by ensuring you have current firmware images.
609 These are distributed as part of the AltOS software bundle that
610 also includes the AltosUI ground station program. Newer ground
611 station versions typically work fine with older firmware versions,
612 so you don't need to update your devices just to try out new
613 software features. You can always download the most recent
614 version from <a class="ulink" href="http://www.altusmetrum.org/AltOS/" target="_top">http://www.altusmetrum.org/AltOS/</a>.
616 We recommend updating TeleMetrum first, before updating TeleDongle.
617 </p><div class="section" title="Updating TeleMetrum Firmware"><div class="titlepage"><div><div><h3 class="title"><a name="id2630289"></a>Updating TeleMetrum Firmware</h3></div></div></div><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
618 Find the 'programming cable' that you got as part of the starter
619 kit, that has a red 8-pin MicroMaTch connector on one end and a
620 red 4-pin MicroMaTch connector on the other end.
621 </li><li class="listitem">
622 Take the 2 screws out of the TeleDongle case to get access
623 to the circuit board.
624 </li><li class="listitem">
625 Plug the 8-pin end of the programming cable to the
626 matching connector on the TeleDongle, and the 4-pin end to the
627 matching connector on the TeleMetrum.
628 Note that each MicroMaTch connector has an alignment pin that
629 goes through a hole in the PC board when you have the cable
631 </li><li class="listitem">
632 Attach a battery to the TeleMetrum board.
633 </li><li class="listitem">
634 Plug the TeleDongle into your computer's USB port, and power
636 </li><li class="listitem">
637 Run AltosUI, and select 'Flash Image' from the File menu.
638 </li><li class="listitem">
639 Pick the TeleDongle device from the list, identifying it as the
641 </li><li class="listitem">
642 Select the image you want put on the TeleMetrum, which should have a
643 name in the form telemetrum-v1.0-0.7.1.ihx. It should be visible
644 in the default directory, if not you may have to poke around
645 your system to find it.
646 </li><li class="listitem">
647 Make sure the configuration parameters are reasonable
648 looking. If the serial number and/or RF configuration
649 values aren't right, you'll need to change them.
650 </li><li class="listitem">
651 Hit the 'OK' button and the software should proceed to flash
652 the TeleMetrum with new firmware, showing a progress bar.
653 </li><li class="listitem">
654 Confirm that the TeleMetrum board seems to have updated ok, which you
655 can do by plugging in to it over USB and using a terminal program
656 to connect to the board and issue the 'v' command to check
658 </li><li class="listitem">
659 If something goes wrong, give it another try.
660 </li></ol></div></div><div class="section" title="Updating TeleDongle Firmware"><div class="titlepage"><div><div><h3 class="title"><a name="id2639681"></a>Updating TeleDongle Firmware</h3></div></div></div><p>
661 Updating TeleDongle's firmware is just like updating TeleMetrum
662 firmware, but you switch which board is the programmer and which
663 is the programming target.
664 </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
665 Find the 'programming cable' that you got as part of the starter
666 kit, that has a red 8-pin MicroMaTch connector on one end and a
667 red 4-pin MicroMaTch connector on the other end.
668 </li><li class="listitem">
669 Find the USB cable that you got as part of the starter kit, and
670 plug the "mini" end in to the mating connector on TeleMetrum.
671 </li><li class="listitem">
672 Take the 2 screws out of the TeleDongle case to get access
673 to the circuit board.
674 </li><li class="listitem">
675 Plug the 8-pin end of the programming cable to the (latching)
676 matching connector on the TeleMetrum, and the 4-pin end to the
677 matching connector on the TeleDongle.
678 Note that each MicroMaTch connector has an alignment pin that
679 goes through a hole in the PC board when you have the cable
681 </li><li class="listitem">
682 Attach a battery to the TeleMetrum board.
683 </li><li class="listitem">
684 Plug both TeleMetrum and TeleDongle into your computer's USB
685 ports, and power up the TeleMetrum.
686 </li><li class="listitem">
687 Run AltosUI, and select 'Flash Image' from the File menu.
688 </li><li class="listitem">
689 Pick the TeleMetrum device from the list, identifying it as the
691 </li><li class="listitem">
692 Select the image you want put on the TeleDongle, which should have a
693 name in the form teledongle-v0.2-0.7.1.ihx. It should be visible
694 in the default directory, if not you may have to poke around
695 your system to find it.
696 </li><li class="listitem">
697 Make sure the configuration parameters are reasonable
698 looking. If the serial number and/or RF configuration
699 values aren't right, you'll need to change them. The TeleDongle
700 serial number is on the "bottom" of the circuit board, and can
701 usually be read through the translucent blue plastic case without
702 needing to remove the board from the case.
703 </li><li class="listitem">
704 Hit the 'OK' button and the software should proceed to flash
705 the TeleDongle with new firmware, showing a progress bar.
706 </li><li class="listitem">
707 Confirm that the TeleDongle board seems to have updated ok, which you
708 can do by plugging in to it over USB and using a terminal program
709 to connect to the board and issue the 'v' command to check
710 the version, etc. Once you're happy, remove the programming cable
711 and put the cover back on the TeleDongle.
712 </li><li class="listitem">
713 If something goes wrong, give it another try.
715 Be careful removing the programming cable from the locking 8-pin
716 connector on TeleMetrum. You'll need a fingernail or perhaps a thin
717 screwdriver or knife blade to gently pry the locking ears out
718 slightly to extract the connector. We used a locking connector on
719 TeleMetrum to help ensure that the cabling to companion boards
720 used in a rocket don't ever come loose accidentally in flight.
721 </p></div></div></div><div class="chapter" title="Chapter 7. AltosUI"><div class="titlepage"><div><div><h2 class="title"><a name="id2637633"></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="#id2654003">Packet Command Mode</a></span></dt><dt><span class="section"><a href="#id2647872">Monitor Flight</a></span></dt><dd><dl><dt><span class="section"><a href="#id2630489">Launch Pad</a></span></dt><dt><span class="section"><a href="#id2650566">Ascent</a></span></dt><dt><span class="section"><a href="#id2651780">Descent</a></span></dt><dt><span class="section"><a href="#id2637083">Landed</a></span></dt><dt><span class="section"><a href="#id2662597">Site Map</a></span></dt></dl></dd><dt><span class="section"><a href="#id2652017">Save Flight Data</a></span></dt><dt><span class="section"><a href="#id2662100">Replay Flight</a></span></dt><dt><span class="section"><a href="#id2648922">Graph Data</a></span></dt><dt><span class="section"><a href="#id2643923">Export Data</a></span></dt><dd><dl><dt><span class="section"><a href="#id2651125">Comma Separated Value Format</a></span></dt><dt><span class="section"><a href="#id2654686">Keyhole Markup Language (for Google Earth)</a></span></dt></dl></dd><dt><span class="section"><a href="#id2645946">Configure TeleMetrum</a></span></dt><dd><dl><dt><span class="section"><a href="#id2634804">Main Deploy Altitude</a></span></dt><dt><span class="section"><a href="#id2628486">Apogee Delay</a></span></dt><dt><span class="section"><a href="#id2657936">Radio Channel</a></span></dt><dt><span class="section"><a href="#id2639511">Radio Calibration</a></span></dt><dt><span class="section"><a href="#id2637390">Callsign</a></span></dt><dt><span class="section"><a href="#id2648042">Maximum Flight Log Size</a></span></dt></dl></dd><dt><span class="section"><a href="#id2639748">Configure AltosUI</a></span></dt><dd><dl><dt><span class="section"><a href="#id2651032">Voice Settings</a></span></dt><dt><span class="section"><a href="#id2649086">Log Directory</a></span></dt><dt><span class="section"><a href="#id2640668">Callsign</a></span></dt><dt><span class="section"><a href="#id2621966">Serial Debug</a></span></dt></dl></dd><dt><span class="section"><a href="#id2651293">Flash Image</a></span></dt><dt><span class="section"><a href="#id2651858">Fire Igniter</a></span></dt></dl></div><p>
722 The AltosUI program provides a graphical user interface for
723 interacting with the Altus Metrum product family, including
724 TeleMetrum and TeleDongle. AltosUI can monitor telemetry data,
725 configure TeleMetrum and TeleDongle devices and many other
726 tasks. The primary interface window provides a selection of
727 buttons, one for each major activity in the system. This manual
728 is split into chapters, each of which documents one of the tasks
729 provided from the top-level toolbar.
730 </p><div class="section" title="Packet Command Mode"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2654003"></a>Packet Command Mode</h2></div><div><h3 class="subtitle">Controlling TeleMetrum Over The Radio Link</h3></div></div></div><p>
731 One of the unique features of the Altus Metrum environment is
732 the ability to create a two way command link between TeleDongle
733 and TeleMetrum using the digital radio transceivers built into
734 each device. This allows you to interact with TeleMetrum from
735 afar, as if it were directly connected to the computer.
737 Any operation which can be performed with TeleMetrum
738 can either be done with TeleMetrum directly connected to
739 the computer via the USB cable, or through the packet
740 link. Simply select the appropriate TeleDongle device when
741 the list of devices is presented and AltosUI will use packet
744 One oddity in the current interface is how AltosUI selects the
745 channel for packet mode communications. Instead of providing
746 an interface to specifically configure the channel, it uses
747 whatever channel was most recently selected for the target
748 TeleDongle device in Monitor Flight mode. If you haven't ever
749 used that mode with the TeleDongle in question, select the
750 Monitor Flight button from the top level UI, pick the
751 appropriate TeleDongle device. Once the flight monitoring
752 window is open, select the desired channel and then close it
753 down again. All Packet Command Mode operations will now use
755 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
756 Save Flight Data—Recover flight data from the rocket without
758 </p></li><li class="listitem"><p>
759 Configure TeleMetrum—Reset apogee delays or main deploy
760 heights to respond to changing launch conditions. You can
761 also 'reboot' the TeleMetrum device. Use this to remotely
762 enable the flight computer by turning TeleMetrum on while
763 horizontal, then once the airframe is oriented for launch,
764 you can reboot TeleMetrum and have it restart in pad mode
765 without having to climb the scary ladder.
766 </p></li><li class="listitem"><p>
767 Fire Igniters—Test your deployment charges without snaking
768 wires out through holes in the airframe. Simply assembly the
769 rocket as if for flight with the apogee and main charges
770 loaded, then remotely command TeleMetrum to fire the
772 </p></li></ul></div><p>
773 Packet command mode uses the same RF channels as telemetry
774 mode. Configure the desired TeleDongle channel using the
775 flight monitor window channel selector and then close that
776 window before performing the desired operation.
778 TeleMetrum only enables packet command mode in 'idle' mode, so
779 make sure you have TeleMetrum lying horizontally when you turn
780 it on. Otherwise, TeleMetrum will start in 'pad' mode ready for
781 flight and will not be listening for command packets from TeleDongle.
783 When packet command mode is enabled, you can monitor the link
784 by watching the lights on the TeleDongle and TeleMetrum
785 devices. The red LED will flash each time TeleDongle or
786 TeleMetrum transmit a packet while the green LED will light up
787 on TeleDongle while it is waiting to receive a packet from
789 </p></div><div class="section" title="Monitor Flight"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2647872"></a>Monitor Flight</h2></div><div><h3 class="subtitle">Receive, Record and Display Telemetry Data</h3></div></div></div><p>
790 Selecting this item brings up a dialog box listing all of the
791 connected TeleDongle devices. When you choose one of these,
792 AltosUI will create a window to display telemetry data as
793 received by the selected TeleDongle device.
795 All telemetry data received are automatically recorded in
796 suitable log files. The name of the files includes the current
797 date and rocket serial and flight numbers.
799 The radio channel being monitored by the TeleDongle device is
800 displayed at the top of the window. You can configure the
801 channel by clicking on the channel box and selecting the desired
802 channel. AltosUI remembers the last channel selected for each
803 TeleDongle and selects that automatically the next time you use
806 Below the TeleDongle channel selector, the window contains a few
807 significant pieces of information about the TeleMetrum providing
808 the telemetry data stream:
809 </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
811 </p></li><li class="listitem"><p>
812 The rocket flight state. Each flight passes through several
813 states including Pad, Boost, Fast, Coast, Drogue, Main and
815 </p></li><li class="listitem"><p>
816 The Received Signal Strength Indicator value. This lets
817 you know how strong a signal TeleDongle is receiving. The
818 radio inside TeleDongle operates down to about -99dBm;
819 weaker signals may not be receiveable. The packet link uses
820 error correction and detection techniques which prevent
821 incorrect data from being reported.
822 </p></li></ul></div><p>
823 Finally, the largest portion of the window contains a set of
824 tabs, each of which contain some information about the rocket.
825 They're arranged in 'flight order' so that as the flight
826 progresses, the selected tab automatically switches to display
827 data relevant to the current state of the flight. You can select
828 other tabs at any time. The final 'table' tab contains all of
829 the telemetry data in one place.
830 </p><div class="section" title="Launch Pad"><div class="titlepage"><div><div><h3 class="title"><a name="id2630489"></a>Launch Pad</h3></div></div></div><p>
831 The 'Launch Pad' tab shows information used to decide when the
832 rocket is ready for flight. The first elements include red/green
833 indicators, if any of these is red, you'll want to evaluate
834 whether the rocket is ready to launch:
835 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
836 Battery Voltage. This indicates whether the LiPo battery
837 powering the TeleMetrum has sufficient charge to last for
838 the duration of the flight. A value of more than
839 3.7V is required for a 'GO' status.
840 </p></li><li class="listitem"><p>
841 Apogee Igniter Voltage. This indicates whether the apogee
842 igniter has continuity. If the igniter has a low
843 resistance, then the voltage measured here will be close
844 to the LiPo battery voltage. A value greater than 3.2V is
845 required for a 'GO' status.
846 </p></li><li class="listitem"><p>
847 Main Igniter Voltage. This indicates whether the main
848 igniter has continuity. If the igniter has a low
849 resistance, then the voltage measured here will be close
850 to the LiPo battery voltage. A value greater than 3.2V is
851 required for a 'GO' status.
852 </p></li><li class="listitem"><p>
853 GPS Locked. This indicates whether the GPS receiver is
854 currently able to compute position information. GPS requires
855 at least 4 satellites to compute an accurate position.
856 </p></li><li class="listitem"><p>
857 GPS Ready. This indicates whether GPS has reported at least
858 10 consecutive positions without losing lock. This ensures
859 that the GPS receiver has reliable reception from the
861 </p></li></ul></div><p>
863 The LaunchPad tab also shows the computed launch pad position
864 and altitude, averaging many reported positions to improve the
867 </p></div><div class="section" title="Ascent"><div class="titlepage"><div><div><h3 class="title"><a name="id2650566"></a>Ascent</h3></div></div></div><p>
868 This tab is shown during Boost, Fast and Coast
869 phases. The information displayed here helps monitor the
870 rocket as it heads towards apogee.
872 The height, speed and acceleration are shown along with the
873 maxium values for each of them. This allows you to quickly
874 answer the most commonly asked questions you'll hear during
877 The current latitude and longitude reported by the GPS are
878 also shown. Note that under high acceleration, these values
879 may not get updated as the GPS receiver loses position
880 fix. Once the rocket starts coasting, the receiver should
881 start reporting position again.
883 Finally, the current igniter voltages are reported as in the
884 Launch Pad tab. This can help diagnose deployment failures
885 caused by wiring which comes loose under high acceleration.
886 </p></div><div class="section" title="Descent"><div class="titlepage"><div><div><h3 class="title"><a name="id2651780"></a>Descent</h3></div></div></div><p>
887 Once the rocket has reached apogee and (we hope) activated the
888 apogee charge, attention switches to tracking the rocket on
889 the way back to the ground, and for dual-deploy flights,
890 waiting for the main charge to fire.
892 To monitor whether the apogee charge operated correctly, the
893 current descent rate is reported along with the current
894 height. Good descent rates generally range from 15-30m/s.
896 To help locate the rocket in the sky, use the elevation and
897 bearing information to figure out where to look. Elevation is
898 in degrees above the horizon. Bearing is reported in degrees
899 relative to true north. Range can help figure out how big the
900 rocket will appear. Note that all of these values are relative
901 to the pad location. If the elevation is near 90°, the rocket
902 is over the pad, not over you.
904 Finally, the igniter voltages are reported in this tab as
905 well, both to monitor the main charge as well as to see what
906 the status of the apogee charge is.
907 </p></div><div class="section" title="Landed"><div class="titlepage"><div><div><h3 class="title"><a name="id2637083"></a>Landed</h3></div></div></div><p>
908 Once the rocket is on the ground, attention switches to
909 recovery. While the radio signal is generally lost once the
910 rocket is on the ground, the last reported GPS position is
911 generally within a short distance of the actual landing location.
913 The last reported GPS position is reported both by
914 latitude and longitude as well as a bearing and distance from
915 the launch pad. The distance should give you a good idea of
916 whether you'll want to walk or hitch a ride. Take the reported
917 latitude and longitude and enter them into your handheld GPS
918 unit and have that compute a track to the landing location.
920 Finally, the maximum height, speed and acceleration reported
921 during the flight are displayed for your admiring observers.
922 </p></div><div class="section" title="Site Map"><div class="titlepage"><div><div><h3 class="title"><a name="id2662597"></a>Site Map</h3></div></div></div><p>
923 When the rocket gets a GPS fix, the Site Map tab will map
924 the rocket's position to make it easier for you to locate the
925 rocket, both while it is in the air, and when it has landed. The
926 rocket's state is indicated by colour: white for pad, red for
927 boost, pink for fast, yellow for coast, light blue for drogue,
928 dark blue for main, and black for landed.
930 The map's scale is approximately 3m (10ft) per pixel. The map
931 can be dragged using the left mouse button. The map will attempt
932 to keep the rocket roughly centred while data is being received.
934 Images are fetched automatically via the Google Maps Static API,
935 and are cached for reuse. If map images cannot be downloaded,
936 the rocket's path will be traced on a dark grey background
938 </p></div></div><div class="section" title="Save Flight Data"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2652017"></a>Save Flight Data</h2></div></div></div><p>
939 TeleMetrum records flight data to its internal flash memory.
940 This data is recorded at a much higher rate than the telemetry
941 system can handle, and is not subject to radio drop-outs. As
942 such, it provides a more complete and precise record of the
943 flight. The 'Save Flight Data' button allows you to read the
944 flash memory and write it to disk.
946 Clicking on the 'Save Flight Data' button brings up a list of
947 connected TeleMetrum and TeleDongle devices. If you select a
948 TeleMetrum device, the flight data will be downloaded from that
949 device directly. If you select a TeleDongle device, flight data
950 will be downloaded from a TeleMetrum device connected via the
951 packet command link to the specified TeleDongle. See the chapter
952 on Packet Command Mode for more information about this.
954 After the device has been selected, a dialog showing the
955 flight data saved in the device will be shown allowing you to
956 select which flights to download and which to delete. With
957 version 0.9 or newer firmware, you must erase flights in order
958 for the space they consume to be reused by another
959 flight. This prevents you from accidentally losing flight data
960 if you neglect to download data before flying again. Note that
961 if there is no more space available in the device, then no
962 data will be recorded for a flight.
964 The filename for each flight log is computed automatically
965 from the recorded flight date, TeleMetrum serial number and
966 flight number information.
967 </p></div><div class="section" title="Replay Flight"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2662100"></a>Replay Flight</h2></div></div></div><p>
968 Select this button and you are prompted to select a flight
969 record file, either a .telem file recording telemetry data or a
970 .eeprom file containing flight data saved from the TeleMetrum
973 Once a flight record is selected, the flight monitor interface
974 is displayed and the flight is re-enacted in real time. Check
975 the Monitor Flight chapter above to learn how this window operates.
976 </p></div><div class="section" title="Graph Data"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2648922"></a>Graph Data</h2></div></div></div><p>
977 Select this button and you are prompted to select a flight
978 record file, either a .telem file recording telemetry data or a
979 .eeprom file containing flight data saved from the TeleMetrum
982 Once a flight record is selected, the acceleration (blue),
983 velocity (green) and altitude (red) of the flight are plotted and
984 displayed, measured in metric units.
986 The graph can be zoomed into a particular area by clicking and
987 dragging down and to the right. Once zoomed, the graph can be
988 reset by clicking and dragging up and to the left. Holding down
989 control and clicking and dragging allows the graph to be panned.
990 The right mouse button causes a popup menu to be displayed, giving
991 you the option save or print the plot.
993 Note that telemetry files will generally produce poor graphs
994 due to the lower sampling rate and missed telemetry packets,
995 and will also often have significant amounts of data received
996 while the rocket was waiting on the pad. Use saved flight data
997 for graphing where possible.
998 </p></div><div class="section" title="Export Data"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2643923"></a>Export Data</h2></div></div></div><p>
999 This tool takes the raw data files and makes them available for
1000 external analysis. When you select this button, you are prompted to select a flight
1001 data file (either .eeprom or .telem will do, remember that
1002 .eeprom files contain higher resolution and more continuous
1003 data). Next, a second dialog appears which is used to select
1004 where to write the resulting file. It has a selector to choose
1005 between CSV and KML file formats.
1006 </p><div class="section" title="Comma Separated Value Format"><div class="titlepage"><div><div><h3 class="title"><a name="id2651125"></a>Comma Separated Value Format</h3></div></div></div><p>
1007 This is a text file containing the data in a form suitable for
1008 import into a spreadsheet or other external data analysis
1009 tool. The first few lines of the file contain the version and
1010 configuration information from the TeleMetrum device, then
1011 there is a single header line which labels all of the
1012 fields. All of these lines start with a '#' character which
1013 most tools can be configured to skip over.
1015 The remaining lines of the file contain the data, with each
1016 field separated by a comma and at least one space. All of
1017 the sensor values are converted to standard units, with the
1018 barometric data reported in both pressure, altitude and
1019 height above pad units.
1020 </p></div><div class="section" title="Keyhole Markup Language (for Google Earth)"><div class="titlepage"><div><div><h3 class="title"><a name="id2654686"></a>Keyhole Markup Language (for Google Earth)</h3></div></div></div><p>
1021 This is the format used by
1022 Googleearth to provide an overlay within that
1023 application. With this, you can use Googleearth to see the
1024 whole flight path in 3D.
1025 </p></div></div><div class="section" title="Configure TeleMetrum"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2645946"></a>Configure TeleMetrum</h2></div></div></div><p>
1026 Select this button and then select either a TeleMetrum or
1027 TeleDongle Device from the list provided. Selecting a TeleDongle
1028 device will use Packet Comamnd Mode to configure remote
1029 TeleMetrum device. Learn how to use this in the Packet Command
1032 The first few lines of the dialog provide information about the
1033 connected TeleMetrum device, including the product name,
1034 software version and hardware serial number. Below that are the
1035 individual configuration entries.
1037 At the bottom of the dialog, there are four buttons:
1038 </p><div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><p>
1039 Save. This writes any changes to the TeleMetrum
1040 configuration parameter block in flash memory. If you don't
1041 press this button, any changes you make will be lost.
1042 </p></li><li class="listitem"><p>
1043 Reset. This resets the dialog to the most recently saved values,
1044 erasing any changes you have made.
1045 </p></li><li class="listitem"><p>
1046 Reboot. This reboots the TeleMetrum device. Use this to
1047 switch from idle to pad mode by rebooting once the rocket is
1048 oriented for flight.
1049 </p></li><li class="listitem"><p>
1050 Close. This closes the dialog. Any unsaved changes will be
1052 </p></li></ul></div><p>
1053 The rest of the dialog contains the parameters to be configured.
1054 </p><div class="section" title="Main Deploy Altitude"><div class="titlepage"><div><div><h3 class="title"><a name="id2634804"></a>Main Deploy Altitude</h3></div></div></div><p>
1055 This sets the altitude (above the recorded pad altitude) at
1056 which the 'main' igniter will fire. The drop-down menu shows
1057 some common values, but you can edit the text directly and
1058 choose whatever you like. If the apogee charge fires below
1059 this altitude, then the main charge will fire two seconds
1060 after the apogee charge fires.
1061 </p></div><div class="section" title="Apogee Delay"><div class="titlepage"><div><div><h3 class="title"><a name="id2628486"></a>Apogee Delay</h3></div></div></div><p>
1062 When flying redundant electronics, it's often important to
1063 ensure that multiple apogee charges don't fire at precisely
1064 the same time as that can overpressurize the apogee deployment
1065 bay and cause a structural failure of the airframe. The Apogee
1066 Delay parameter tells the flight computer to fire the apogee
1067 charge a certain number of seconds after apogee has been
1069 </p></div><div class="section" title="Radio Channel"><div class="titlepage"><div><div><h3 class="title"><a name="id2657936"></a>Radio Channel</h3></div></div></div><p>
1070 This configures which of the 10 radio channels to use for both
1071 telemetry and packet command mode. Note that if you set this
1072 value via packet command mode, you will have to reconfigure
1073 the TeleDongle channel before you will be able to use packet
1075 </p></div><div class="section" title="Radio Calibration"><div class="titlepage"><div><div><h3 class="title"><a name="id2639511"></a>Radio Calibration</h3></div></div></div><p>
1076 The radios in every Altus Metrum device are calibrated at the
1077 factory to ensure that they transmit and receive on the
1078 specified frequency for each channel. You can adjust that
1079 calibration by changing this value. To change the TeleDongle's
1080 calibration, you must reprogram the unit completely.
1081 </p></div><div class="section" title="Callsign"><div class="titlepage"><div><div><h3 class="title"><a name="id2637390"></a>Callsign</h3></div></div></div><p>
1082 This sets the callsign included in each telemetry packet. Set this
1083 as needed to conform to your local radio regulations.
1084 </p></div><div class="section" title="Maximum Flight Log Size"><div class="titlepage"><div><div><h3 class="title"><a name="id2648042"></a>Maximum Flight Log Size</h3></div></div></div><p>
1085 This sets the space (in kilobytes) allocated for each flight
1086 log. The available space will be divided into chunks of this
1087 size. A smaller value will allow more flights to be stored,
1088 a larger value will record data from longer flights.
1090 During ascent, TeleMetrum records barometer and
1091 accelerometer values 100 times per second, other analog
1092 information (voltages and temperature) 6 times per second
1093 and GPS data once per second. During descent, the non-GPS
1094 data is recorded 1/10th as often. Each barometer +
1095 accelerometer record takes 8 bytes.
1097 The default, 192kB, will store over 200 seconds of data at
1098 the ascent rate, or over 2000 seconds of data at the descent
1099 rate. That's plenty for most flights. This leaves enough
1100 storage for five flights in a 1MB system, or 10 flights in a
1103 The configuration block takes the last available block of
1104 memory, on v1.0 boards that's just 256 bytes. However, the
1105 flash part on the v1.1 boards uses 64kB for each block.
1106 </p></div></div><div class="section" title="Configure AltosUI"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2639748"></a>Configure AltosUI</h2></div></div></div><p>
1107 This button presents a dialog so that you can configure the AltosUI global settings.
1108 </p><div class="section" title="Voice Settings"><div class="titlepage"><div><div><h3 class="title"><a name="id2651032"></a>Voice Settings</h3></div></div></div><p>
1109 AltosUI provides voice annoucements during flight so that you
1110 can keep your eyes on the sky and still get information about
1111 the current flight status. However, sometimes you don't want
1113 </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>
1114 Test Voice—Plays a short message allowing you to verify
1115 that the audio systme is working and the volume settings
1117 </p></li></ul></div></div><div class="section" title="Log Directory"><div class="titlepage"><div><div><h3 class="title"><a name="id2649086"></a>Log Directory</h3></div></div></div><p>
1118 AltosUI logs all telemetry data and saves all TeleMetrum flash
1119 data to this directory. This directory is also used as the
1120 staring point when selecting data files for display or export.
1122 Click on the directory name to bring up a directory choosing
1123 dialog, select a new directory and click 'Select Directory' to
1124 change where AltosUI reads and writes data files.
1125 </p></div><div class="section" title="Callsign"><div class="titlepage"><div><div><h3 class="title"><a name="id2640668"></a>Callsign</h3></div></div></div><p>
1126 This value is used in command packet mode and is transmitted
1127 in each packet sent from TeleDongle and received from
1128 TeleMetrum. It is not used in telemetry mode as that transmits
1129 packets only from TeleMetrum to TeleDongle. Configure this
1130 with the AltosUI operators callsign as needed to comply with
1131 your local radio regulations.
1132 </p></div><div class="section" title="Serial Debug"><div class="titlepage"><div><div><h3 class="title"><a name="id2621966"></a>Serial Debug</h3></div></div></div><p>
1133 This causes all communication with a connected device to be
1134 dumped to the console from which AltosUI was started. If
1135 you've started it from an icon or menu entry, the output
1136 will simply be discarded. This mode can be useful to debug
1137 various serial communication issues.
1138 </p></div></div><div class="section" title="Flash Image"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2651293"></a>Flash Image</h2></div></div></div><p>
1139 This reprograms any Altus Metrum device by using a TeleMetrum or
1140 TeleDongle as a programming dongle. Please read the directions
1141 for connecting the programming cable in the main TeleMetrum
1142 manual before reading these instructions.
1144 Once you have the programmer and target devices connected,
1145 push the 'Flash Image' button. That will present a dialog box
1146 listing all of the connected devices. Carefully select the
1147 programmer device, not the device to be programmed.
1149 Next, select the image to flash to the device. These are named
1150 with the product name and firmware version. The file selector
1151 will start in the directory containing the firmware included
1152 with the AltosUI package. Navigate to the directory containing
1153 the desired firmware if it isn't there.
1155 Next, a small dialog containing the device serial number and
1156 RF calibration values should appear. If these values are
1157 incorrect (possibly due to a corrupted image in the device),
1158 enter the correct values here.
1160 Finally, a dialog containing a progress bar will follow the
1161 programming process.
1163 When programming is complete, the target device will
1164 reboot. Note that if the target device is connected via USB, you
1165 will have to unplug it and then plug it back in for the USB
1166 connection to reset so that you can communicate with the device
1168 </p></div><div class="section" title="Fire Igniter"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2651858"></a>Fire Igniter</h2></div></div></div><p>
1169 This activates the igniter circuits in TeleMetrum to help test
1170 recovery systems deployment. Because this command can operate
1171 over the Packet Command Link, you can prepare the rocket as
1172 for flight and then test the recovery system without needing
1173 to snake wires inside the airframe.
1175 Selecting the 'Fire Igniter' button brings up the usual device
1176 selection dialog. Pick the desired TeleDongle or TeleMetrum
1177 device. This brings up another window which shows the current
1178 continutity test status for both apogee and main charges.
1180 Next, select the desired igniter to fire. This will enable the
1183 Select the 'Arm' button. This enables the 'Fire' button. The
1184 word 'Arm' is replaced by a countdown timer indicating that
1185 you have 10 seconds to press the 'Fire' button or the system
1186 will deactivate, at which point you start over again at
1187 selecting the desired igniter.
1188 </p></div></div><div class="chapter" title="Chapter 8. Using Altus Metrum Products"><div class="titlepage"><div><div><h2 class="title"><a name="id2646109"></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="#id2651706">Being Legal</a></span></dt><dt><span class="section"><a href="#id2649421">In the Rocket</a></span></dt><dt><span class="section"><a href="#id2648265">On the Ground</a></span></dt><dt><span class="section"><a href="#id2654896">Data Analysis</a></span></dt><dt><span class="section"><a href="#id2661470">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="id2651706"></a>Being Legal</h2></div></div></div><p>
1189 First off, in the US, you need an <a class="ulink" href="http://www.altusmetrum.org/Radio/" target="_top">amateur radio license</a> or
1190 other authorization to legally operate the radio transmitters that are part
1192 </p></div><div class="section" title="In the Rocket"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2649421"></a>In the Rocket</h2></div></div></div><p>
1193 In the rocket itself, you just need a <a class="ulink" href="http://www.altusmetrum.org/TeleMetrum/" target="_top">TeleMetrum</a> board and
1194 a LiPo rechargeable battery. An 860mAh battery weighs less than a 9V
1195 alkaline battery, and will run a <a class="ulink" href="http://www.altusmetrum.org/TeleMetrum/" target="_top">TeleMetrum</a> for hours.
1197 By default, we ship TeleMetrum with a simple wire antenna. If your
1198 electronics bay or the airframe it resides within is made of carbon fiber,
1199 which is opaque to RF signals, you may choose to have an SMA connector
1200 installed so that you can run a coaxial cable to an antenna mounted
1201 elsewhere in the rocket.
1202 </p></div><div class="section" title="On the Ground"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2648265"></a>On the Ground</h2></div></div></div><p>
1203 To receive the data stream from the rocket, you need an antenna and short
1204 feedline connected to one of our <a class="ulink" href="http://www.altusmetrum.org/TeleDongle/" target="_top">TeleDongle</a> units. The
1205 TeleDongle in turn plugs directly into the USB port on a notebook
1206 computer. Because TeleDongle looks like a simple serial port, your computer
1207 does not require special device drivers... just plug it in.
1209 The GUI tool, AltosUI, is written in Java and runs across
1210 Linux, Mac OS and Windows. There's also a suite of C tools
1211 for Linux which can perform most of the same tasks.
1213 After the flight, you can use the RF link to extract the more detailed data
1214 logged in the rocket, or you can use a mini USB cable to plug into the
1215 TeleMetrum board directly. Pulling out the data without having to open up
1216 the rocket is pretty cool! A USB cable is also how you charge the LiPo
1217 battery, so you'll want one of those anyway... the same cable used by lots
1218 of digital cameras and other modern electronic stuff will work fine.
1220 If your rocket lands out of sight, you may enjoy having a hand-held GPS
1221 receiver, so that you can put in a waypoint for the last reported rocket
1222 position before touch-down. This makes looking for your rocket a lot like
1223 Geo-Cacheing... just go to the waypoint and look around starting from there.
1225 You may also enjoy having a ham radio "HT" that covers the 70cm band... you
1226 can use that with your antenna to direction-find the rocket on the ground
1227 the same way you can use a Walston or Beeline tracker. This can be handy
1228 if the rocket is hiding in sage brush or a tree, or if the last GPS position
1229 doesn't get you close enough because the rocket dropped into a canyon, or
1230 the wind is blowing it across a dry lake bed, or something like that... Keith
1231 and Bdale both currently own and use the Yaesu VX-7R at launches.
1233 So, to recap, on the ground the hardware you'll need includes:
1234 </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
1235 an antenna and feedline
1236 </li><li class="listitem">
1238 </li><li class="listitem">
1240 </li><li class="listitem">
1241 optionally, a handheld GPS receiver
1242 </li><li class="listitem">
1243 optionally, an HT or receiver covering 435 Mhz
1246 The best hand-held commercial directional antennas we've found for radio
1247 direction finding rockets are from
1248 <a class="ulink" href="http://www.arrowantennas.com/" target="_top">
1251 The 440-3 and 440-5 are both good choices for finding a
1252 TeleMetrum-equipped rocket when used with a suitable 70cm HT.
1253 </p></div><div class="section" title="Data Analysis"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2654896"></a>Data Analysis</h2></div></div></div><p>
1254 Our software makes it easy to log the data from each flight, both the
1255 telemetry received over the RF link during the flight itself, and the more
1256 complete data log recorded in the DataFlash memory on the TeleMetrum
1257 board. Once this data is on your computer, our postflight tools make it
1258 easy to quickly get to the numbers everyone wants, like apogee altitude,
1259 max acceleration, and max velocity. You can also generate and view a
1260 standard set of plots showing the altitude, acceleration, and
1261 velocity of the rocket during flight. And you can even export a data file
1262 useable with Google Maps and Google Earth for visualizing the flight path
1263 in two or three dimensions!
1265 Our ultimate goal is to emit a set of files for each flight that can be
1266 published as a web page per flight, or just viewed on your local disk with
1268 </p></div><div class="section" title="Future Plans"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="id2661470"></a>Future Plans</h2></div></div></div><p>
1269 In the future, we intend to offer "companion boards" for the rocket that will
1270 plug in to TeleMetrum to collect additional data, provide more pyro channels,
1271 and so forth. A reference design for a companion board will be documented
1272 soon, and will be compatible with open source Arduino programming tools.
1274 We are also working on the design of a hand-held ground terminal that will
1275 allow monitoring the rocket's status, collecting data during flight, and
1276 logging data after flight without the need for a notebook computer on the
1277 flight line. Particularly since it is so difficult to read most notebook
1278 screens in direct sunlight, we think this will be a great thing to have.
1280 Because all of our work is open, both the hardware designs and the software,
1281 if you have some great idea for an addition to the current Altus Metrum family,
1282 feel free to dive in and help! Or let us know what you'd like to see that
1283 we aren't already working on, and maybe we'll get excited about it too...
1284 </p></div></div></div></body></html>
projects / web / altusmetrum / blob