1 <?xml version="1.0" encoding="utf-8"?>
2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "/usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd">
5 <title>The Altus Metrum System</title>
6 <subtitle>An Owner's Manual for Altus Metrum Rocketry Electronics</subtitle>
9 <firstname>Bdale</firstname>
10 <surname>Garbee</surname>
13 <firstname>Keith</firstname>
14 <surname>Packard</surname>
17 <firstname>Bob</firstname>
18 <surname>Finch</surname>
21 <firstname>Anthony</firstname>
22 <surname>Towns</surname>
26 <holder>Bdale Garbee and Keith Packard</holder>
30 <imagedata fileref="../themes/background.png" width="6.0in"/>
35 This document is released under the terms of the
36 <ulink url="http://creativecommons.org/licenses/by-sa/3.0/">
37 Creative Commons ShareAlike 3.0
44 <revnumber>1.4</revnumber>
45 <date>15 June 2014</date>
47 Major release adding TeleGPS support.
51 <revnumber>1.3.2</revnumber>
52 <date>24 January 2014</date>
54 Bug fixes for TeleMega and AltosUI.
58 <revnumber>1.3.1</revnumber>
59 <date>21 January 2014</date>
61 Bug fixes for TeleMega and TeleMetrum v2.0 along with a few
62 small UI improvements.
66 <revnumber>1.3</revnumber>
67 <date>12 November 2013</date>
69 Updated for software version 1.3. Version 1.3 adds support
70 for TeleMega, TeleMetrum v2.0, TeleMini v2.0 and EasyMini
71 and fixes bugs in AltosUI and the AltOS firmware.
75 <revnumber>1.2.1</revnumber>
76 <date>21 May 2013</date>
78 Updated for software version 1.2. Version 1.2 adds support
79 for TeleBT and AltosDroid. It also adds a few minor features
80 and fixes bugs in AltosUI and the AltOS firmware.
84 <revnumber>1.2</revnumber>
85 <date>18 April 2013</date>
87 Updated for software version 1.2. Version 1.2 adds support
88 for MicroPeak and the MicroPeak USB interface.
92 <revnumber>1.1.1</revnumber>
93 <date>16 September 2012</date>
95 Updated for software version 1.1.1 Version 1.1.1 fixes a few
96 bugs found in version 1.1.
100 <revnumber>1.1</revnumber>
101 <date>13 September 2012</date>
103 Updated for software version 1.1. Version 1.1 has new
104 features but is otherwise compatible with version 1.0.
108 <revnumber>1.0</revnumber>
109 <date>24 August 2011</date>
111 Updated for software version 1.0. Note that 1.0 represents a
112 telemetry format change, meaning both ends of a link
113 (TeleMetrum/TeleMini and TeleDongle) must be updated or
114 communications will fail.
118 <revnumber>0.9</revnumber>
119 <date>18 January 2011</date>
121 Updated for software version 0.9. Note that 0.9 represents a
122 telemetry format change, meaning both ends of a link (TeleMetrum and
123 TeleDongle) must be updated or communications will fail.
127 <revnumber>0.8</revnumber>
128 <date>24 November 2010</date>
129 <revremark>Updated for software version 0.8 </revremark>
134 <title>Acknowledgments</title>
136 Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing “The
137 Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter
138 Kit” which formed the basis of the original Getting Started chapter
139 in this manual. Bob was one of our first customers for a production
140 TeleMetrum, and his continued enthusiasm and contributions
141 are immensely gratifying and highly appreciated!
144 And thanks to Anthony (AJ) Towns for major contributions including
145 the AltosUI graphing and site map code and associated documentation.
146 Free software means that our customers and friends can become our
147 collaborators, and we certainly appreciate this level of
151 Have fun using these products, and we hope to meet all of you
152 out on the rocket flight line somewhere.
155 NAR #87103, TRA #12201
157 Keith Packard, KD7SQG
158 NAR #88757, TRA #12200
163 <title>Introduction and Overview</title>
165 Welcome to the Altus Metrum community! Our circuits and software reflect
166 our passion for both hobby rocketry and Free Software. We hope their
167 capabilities and performance will delight you in every way, but by
168 releasing all of our hardware and software designs under open licenses,
169 we also hope to empower you to take as active a role in our collective
173 The first device created for our community was TeleMetrum, a dual
174 deploy altimeter with fully integrated GPS and radio telemetry
175 as standard features, and a “companion interface” that will
176 support optional capabilities in the future. The latest version
177 of TeleMetrum, v2.0, has all of the same features but with
178 improved sensors and radio to offer increased performance.
181 Our second device was TeleMini, a dual deploy altimeter with
182 radio telemetry and radio direction finding. The first version
183 of this device was only 13mm by 38mm (½ inch by 1½ inches) and
184 could fit easily in an 18mm air-frame. The latest version, v2.0,
185 includes a beeper, USB data download and extended on-board
186 flight logging, along with an improved barometric sensor.
189 TeleMega is our most sophisticated device, including six pyro
190 channels (four of which are fully programmable), integrated GPS,
191 integrated gyroscopes for staging/air-start inhibit and high
192 performance telemetry.
195 EasyMini is a dual-deploy altimeter with logging and built-in
199 TeleDongle was our first ground station, providing a USB to RF
200 interfaces for communicating with the altimeters. Combined with
201 your choice of antenna and notebook computer, TeleDongle and our
202 associated user interface software form a complete ground
203 station capable of logging and displaying in-flight telemetry,
204 aiding rocket recovery, then processing and archiving flight
205 data for analysis and review.
208 For a slightly more portable ground station experience that also
209 provides direct rocket recovery support, TeleBT offers flight
210 monitoring and data logging using a Bluetooth™ connection between
211 the receiver and an Android device that has the AltosDroid
212 application installed from the Google Play store.
215 More products will be added to the Altus Metrum family over time, and
216 we currently envision that this will be a single, comprehensive manual
217 for the entire product family.
221 <title>Getting Started</title>
223 The first thing to do after you check the inventory of parts in your
224 “starter kit” is to charge the battery.
227 For TeleMetrum and TeleMega, the battery can be charged by plugging it into the
228 corresponding socket of the device and then using the USB
229 cable to plug the flight computer into your computer's USB socket. The
230 on-board circuitry will charge the battery whenever it is plugged
231 in, because the on-off switch does NOT control the
235 On TeleMetrum v1 boards, when the GPS chip is initially
236 searching for satellites, TeleMetrum will consume more current
237 than it pulls from the USB port, so the battery must be
238 attached in order to get satellite lock. Once GPS is locked,
239 the current consumption goes back down enough to enable charging
240 while running. So it's a good idea to fully charge the battery
241 as your first item of business so there is no issue getting and
242 maintaining satellite lock. The yellow charge indicator led
243 will go out when the battery is nearly full and the charger goes
244 to trickle charge. It can take several hours to fully recharge a
245 deeply discharged battery.
248 TeleMetrum v2.0 and TeleMega use a higher power battery charger,
249 allowing them to charge the battery while running the board at
250 maximum power. When the battery is charging, or when the board
251 is consuming a lot of power, the red LED will be lit. When the
252 battery is fully charged, the green LED will be lit. When the
253 battery is damaged or missing, both LEDs will be lit, which
257 The Lithium Polymer TeleMini and EasyMini battery can be charged by
258 disconnecting it from the board and plugging it into a
259 standalone battery charger such as the LipoCharger product
260 included in TeleMini Starter Kits, and connecting that via a USB
261 cable to a laptop or other USB power source.
264 You can also choose to use another battery with TeleMini v2.0
265 and EasyMini, anything supplying between 4 and 12 volts should
266 work fine (like a standard 9V battery), but if you are planning
267 to fire pyro charges, ground testing is required to verify that
268 the battery supplies enough current to fire your chosen e-matches.
271 The other active device in the starter kit is the TeleDongle USB to
272 RF interface. If you plug it in to your Mac or Linux computer it should
273 “just work”, showing up as a serial port device. Windows systems need
274 driver information that is part of the AltOS download to know that the
275 existing USB modem driver will work. We therefore recommend installing
276 our software before plugging in TeleDongle if you are using a Windows
277 computer. If you are using an older version of Linux and are having
278 problems, try moving to a fresher kernel (2.6.33 or newer).
281 Next you should obtain and install the AltOS software. The AltOS
282 distribution includes the AltosUI ground station program, current
284 images for all of the hardware, and a number of standalone
285 utilities that are rarely needed. Pre-built binary packages are
286 available for Linux, Microsoft Windows, and recent MacOSX
287 versions. Full source code and build instructions are also
288 available. The latest version may always be downloaded from
289 <ulink url="http://altusmetrum.org/AltOS"/>.
292 If you're using a TeleBT instead of the TeleDongle, you'll want to
293 install the AltosDroid application from the Google Play store on an
294 Android device. You don't need a data plan to use AltosDroid, but
295 without network access, the Map view will be less useful as it
296 won't contain any map data. You can also use TeleBT connected
297 over USB with your laptop computer; it acts exactly like a
298 TeleDongle. Anywhere this manual talks about TeleDongle, you can
299 also read that as 'and TeleBT when connected via USB'.
303 <title>Handling Precautions</title>
305 All Altus Metrum products are sophisticated electronic devices.
306 When handled gently and properly installed in an air-frame, they
307 will deliver impressive results. However, as with all electronic
308 devices, there are some precautions you must take.
311 The Lithium Polymer rechargeable batteries have an
312 extraordinary power density. This is great because we can fly with
313 much less battery mass than if we used alkaline batteries or previous
314 generation rechargeable batteries... but if they are punctured
315 or their leads are allowed to short, they can and will release their
317 Thus we recommend that you take some care when handling our batteries
318 and consider giving them some extra protection in your air-frame. We
319 often wrap them in suitable scraps of closed-cell packing foam before
320 strapping them down, for example.
323 The barometric sensors used on all of our flight computers are
324 sensitive to sunlight. In normal mounting situations, the baro sensor
325 and all of the other surface mount components
326 are “down” towards whatever the underlying mounting surface is, so
327 this is not normally a problem. Please consider this when designing an
328 installation in an air-frame with a see-through plastic payload bay. It
329 is particularly important to
330 consider this with TeleMini v1.0, both because the baro sensor is on the
331 “top” of the board, and because many model rockets with payload bays
332 use clear plastic for the payload bay! Replacing these with an opaque
333 cardboard tube, painting them, or wrapping them with a layer of masking
334 tape are all reasonable approaches to keep the sensor out of direct
338 The barometric sensor sampling port must be able to “breathe”,
339 both by not being covered by foam or tape or other materials that might
340 directly block the hole on the top of the sensor, and also by having a
341 suitable static vent to outside air.
344 As with all other rocketry electronics, Altus Metrum altimeters must
345 be protected from exposure to corrosive motor exhaust and ejection
350 <title>Altus Metrum Hardware</title>
352 <title>General Usage Instructions</title>
354 Here are general instructions for hooking up an Altus Metrum
355 flight computer. Instructions specific to each model will be
356 found in the section devoted to that model below.
359 To prevent electrical interference from affecting the
360 operation of the flight computer, it's important to always
361 twist pairs of wires connected to the board. Twist the switch
362 leads, the pyro leads and the battery leads. This reduces
363 interference through a mechanism called common mode rejection.
366 <title>Hooking Up Lithium Polymer Batteries</title>
368 All Altus Metrum flight computers have a two pin JST PH
369 series connector to connect up a single-cell Lithium Polymer
370 cell (3.7V nominal). You can purchase matching batteries
371 from the Altus Metrum store, or other vendors, or you can
372 make your own. Pin 1 of the connector is positive, pin 2 is
373 negative. Spark Fun sells a cable with the connector
374 attached, which they call a <ulink
375 url="https://www.sparkfun.com/products/9914">JST Jumper 2
376 Wire Assembly</ulink>.
379 Many RC vendors also sell lithium polymer batteries with
380 this same connector. All that we have found use the opposite
381 polarity, and if you use them that way, you will damage or
382 destroy the flight computer.
386 <title>Hooking Up Pyro Charges</title>
388 Altus Metrum flight computers always have two screws for
389 each pyro charge. This means you shouldn't need to put two
390 wires into a screw terminal or connect leads from pyro
391 charges together externally.
394 On the flight computer, one lead from each charge is hooked
395 to the positive battery terminal through the power switch.
396 The other lead is connected through the pyro circuit, which
397 is connected to the negative battery terminal when the pyro
402 <title>Hooking Up a Power Switch</title>
404 Altus Metrum flight computers need an external power switch
405 to turn them on. This disconnects both the computer and the
406 pyro charges from the battery, preventing the charges from
407 firing when in the Off position. The switch is in-line with
408 the positive battery terminal.
411 <title>Using an External Active Switch Circuit</title>
413 You can use an active switch circuit, such as the
414 Featherweight Magnetic Switch, with any Altus Metrum
415 flight computer. These require three connections, one to
416 the battery, one to the positive power input on the flight
417 computer and one to ground. Find instructions on how to
418 hook these up for each flight computer below. The follow
419 the instructions that come with your active switch to
425 <title>Using a Separate Pyro Battery</title>
427 As mentioned above in the section on hooking up pyro
428 charges, one lead for each of the pyro charges is connected
429 through the power switch directly to the positive battery
430 terminal. The other lead is connected to the pyro circuit,
431 which connects it to the negative battery terminal when the
432 pyro circuit is fired. The pyro circuit on all of the flight
433 computers is designed to handle up to 16V.
436 To use a separate pyro battery, connect the negative pyro
437 battery terminal to the flight computer ground terminal,
438 the positive battery terminal to the igniter and the other
439 igniter lead to the negative pyro terminal on the flight
440 computer. When the pyro channel fires, it will complete the
441 circuit between the negative pyro terminal and the ground
442 terminal, firing the igniter. Specific instructions on how
443 to hook this up will be found in each section below.
447 <title>Using a Different Kind of Battery</title>
449 EasyMini and TeleMini v2 are designed to use either a
450 lithium polymer battery or any other battery producing
451 between 4 and 12 volts, such as a rectangular 9V
452 battery. TeleMega and TeleMetrum are not designed for this,
453 and must only be powered by a lithium polymer battery. Find
454 instructions on how to use other batteries in the EasyMini
455 and TeleMini sections below.
460 <title>Specifications</title>
462 Here's the full set of Altus Metrum products, both in
463 production and retired.
466 <title>Altus Metrum Electronics</title>
467 <?dbfo keep-together="always"?>
468 <tgroup cols='8' align='center' colsep='1' rowsep='1'>
469 <colspec align='center' colwidth='*' colname='Device'/>
470 <colspec align='center' colwidth='*' colname='Barometer'/>
471 <colspec align='center' colwidth='*' colname='Z-axis accelerometer'/>
472 <colspec align='center' colwidth='*' colname='GPS'/>
473 <colspec align='center' colwidth='*' colname='3D sensors'/>
474 <colspec align='center' colwidth='*' colname='Storage'/>
475 <colspec align='center' colwidth='*' colname='RF'/>
476 <colspec align='center' colwidth='*' colname='Battery'/>
479 <entry align='center'>Device</entry>
480 <entry align='center'>Barometer</entry>
481 <entry align='center'>Z-axis accelerometer</entry>
482 <entry align='center'>GPS</entry>
483 <entry align='center'>3D sensors</entry>
484 <entry align='center'>Storage</entry>
485 <entry align='center'>RF Output</entry>
486 <entry align='center'>Battery</entry>
491 <entry>TeleMetrum v1.0</entry>
492 <entry><para>MP3H6115 10km (33k')</para></entry>
493 <entry><para>MMA2202 50g</para></entry>
494 <entry>SkyTraq</entry>
501 <entry>TeleMetrum v1.1</entry>
502 <entry><para>MP3H6115 10km (33k')</para></entry>
503 <entry><para>MMA2202 50g</para></entry>
504 <entry>SkyTraq</entry>
511 <entry>TeleMetrum v1.2</entry>
512 <entry><para>MP3H6115 10km (33k')</para></entry>
513 <entry><para>ADXL78 70g</para></entry>
514 <entry>SkyTraq</entry>
521 <entry>TeleMetrum v2.0</entry>
522 <entry><para>MS5607 30km (100k')</para></entry>
523 <entry><para>MMA6555 102g</para></entry>
524 <entry>uBlox Max-7Q</entry>
531 <entry><para>TeleMini <?linebreak?>v1.0</para></entry>
532 <entry><para>MP3H6115 10km (33k')</para></entry>
541 <entry>TeleMini <?linebreak?>v2.0</entry>
542 <entry><para>MS5607 30km (100k')</para></entry>
548 <entry>3.7-12V</entry>
551 <entry>EasyMini <?linebreak?>v1.0</entry>
552 <entry><para>MS5607 30km (100k')</para></entry>
558 <entry>3.7-12V</entry>
561 <entry>TeleMega <?linebreak?>v1.0</entry>
562 <entry><para>MS5607 30km (100k')</para></entry>
563 <entry><para>MMA6555 102g</para></entry>
564 <entry>uBlox Max-7Q</entry>
565 <entry><para>MPU6000 HMC5883</para></entry>
574 <title>Altus Metrum Boards</title>
575 <?dbfo keep-together="always"?>
576 <tgroup cols='6' align='center' colsep='1' rowsep='1'>
577 <colspec align='center' colwidth='*' colname='Device'/>
578 <colspec align='center' colwidth='*' colname='Connectors'/>
579 <colspec align='center' colwidth='*' colname='Screw Terminals'/>
580 <colspec align='center' colwidth='*' colname='Width'/>
581 <colspec align='center' colwidth='*' colname='Length'/>
582 <colspec align='center' colwidth='*' colname='Tube Size'/>
585 <entry align='center'>Device</entry>
586 <entry align='center'>Connectors</entry>
587 <entry align='center'>Screw Terminals</entry>
588 <entry align='center'>Width</entry>
589 <entry align='center'>Length</entry>
590 <entry align='center'>Tube Size</entry>
595 <entry>TeleMetrum</entry>
599 Companion<?linebreak?>
603 <entry><para>Apogee pyro <?linebreak?>Main pyro <?linebreak?>Switch</para></entry>
604 <entry>1 inch (2.54cm)</entry>
605 <entry>2 ¾ inch (6.99cm)</entry>
606 <entry>29mm coupler</entry>
609 <entry><para>TeleMini <?linebreak?>v1.0</para></entry>
616 Apogee pyro <?linebreak?>
619 <entry>½ inch (1.27cm)</entry>
620 <entry>1½ inch (3.81cm)</entry>
621 <entry>18mm coupler</entry>
624 <entry>TeleMini <?linebreak?>v2.0</entry>
632 Apogee pyro <?linebreak?>
633 Main pyro <?linebreak?>
634 Battery <?linebreak?>
637 <entry>0.8 inch (2.03cm)</entry>
638 <entry>1½ inch (3.81cm)</entry>
639 <entry>24mm coupler</entry>
642 <entry>EasyMini</entry>
649 Apogee pyro <?linebreak?>
650 Main pyro <?linebreak?>
651 Battery <?linebreak?>
654 <entry>0.8 inch (2.03cm)</entry>
655 <entry>1½ inch (3.81cm)</entry>
656 <entry>24mm coupler</entry>
659 <entry>TeleMega</entry>
663 Companion<?linebreak?>
668 Apogee pyro <?linebreak?>
669 Main pyro<?linebreak?>
670 Pyro A-D<?linebreak?>
674 <entry>1¼ inch (3.18cm)</entry>
675 <entry>3¼ inch (8.26cm)</entry>
676 <entry>38mm coupler</entry>
683 <title>TeleMetrum</title>
687 <imagedata fileref="telemetrum-v1.1-thside.jpg" width="5.5in" scalefit="1"/>
692 TeleMetrum is a 1 inch by 2¾ inch circuit board. It was designed to
693 fit inside coupler for 29mm air-frame tubing, but using it in a tube that
694 small in diameter may require some creativity in mounting and wiring
695 to succeed! The presence of an accelerometer means TeleMetrum should
696 be aligned along the flight axis of the airframe, and by default the ¼
697 wave UHF wire antenna should be on the nose-cone end of the board. The
698 antenna wire is about 7 inches long, and wiring for a power switch and
699 the e-matches for apogee and main ejection charges depart from the
700 fin can end of the board, meaning an ideal “simple” avionics
701 bay for TeleMetrum should have at least 10 inches of interior length.
704 <title>TeleMetrum Screw Terminals</title>
706 TeleMetrum has six screw terminals on the end of the board
707 opposite the telemetry antenna. Two are for the power
708 switch, and two each for the apogee and main igniter
709 circuits. Using the picture above and starting from the top,
710 the terminals are as follows:
713 <title>TeleMetrum Screw Terminals</title>
714 <?dbfo keep-together="always"?>
715 <tgroup cols='3' align='center' colsep='1' rowsep='1'>
716 <colspec align='center' colwidth='*' colname='Pin #'/>
717 <colspec align='center' colwidth='2*' colname='Pin Name'/>
718 <colspec align='left' colwidth='5*' colname='Description'/>
721 <entry align='center'>Terminal #</entry>
722 <entry align='center'>Terminal Name</entry>
723 <entry align='center'>Description</entry>
729 <entry>Switch Output</entry>
730 <entry>Switch connection to flight computer</entry>
734 <entry>Switch Input</entry>
735 <entry>Switch connection to positive battery terminal</entry>
739 <entry>Main +</entry>
740 <entry>Main pyro channel common connection to battery +</entry>
744 <entry>Main -</entry>
745 <entry>Main pyro channel connection to pyro circuit</entry>
749 <entry>Apogee +</entry>
750 <entry>Apogee pyro channel common connection to battery +</entry>
754 <entry>Apogee -</entry>
755 <entry>Apogee pyro channel connection to pyro circuit</entry>
762 <title>Using a Separate Pyro Battery with TeleMetrum</title>
764 As described above, using an external pyro battery involves
765 connecting the negative battery terminal to the flight
766 computer ground, connecting the positive battery terminal to
767 one of the igniter leads and connecting the other igniter
768 lead to the per-channel pyro circuit connection.
771 To connect the negative battery terminal to the TeleMetrum
772 ground, insert a small piece of wire, 24 to 28 gauge
773 stranded, into the GND hole just above the screw terminal
774 strip and solder it in place.
777 Connecting the positive battery terminal to the pyro
778 charges must be done separate from TeleMetrum, by soldering
779 them together or using some other connector.
782 The other lead from each pyro charge is then inserted into
783 the appropriate per-pyro channel screw terminal (terminal 4 for the
784 Main charge, terminal 6 for the Apogee charge).
788 <title>Using an Active Switch with TeleMetrum</title>
790 As explained above, an external active switch requires three
791 connections, one to the positive battery terminal, one to
792 the flight computer positive input and one to ground.
795 The positive battery terminal is available on screw terminal
796 2, the positive flight computer input is on terminal 1. To
797 hook a lead to ground, solder a piece of wire, 24 to 28
798 gauge stranded, to the GND hole just above terminal 1.
803 <title>TeleMini v1.0</title>
807 <imagedata fileref="telemini-v1-top.jpg" width="5.5in" scalefit="1"/>
812 TeleMini v1.0 is ½ inches by 1½ inches. It was
813 designed to fit inside an 18mm air-frame tube, but using it in
814 a tube that small in diameter may require some creativity in
815 mounting and wiring to succeed! Since there is no
816 accelerometer, TeleMini can be mounted in any convenient
817 orientation. The default ¼ wave UHF wire antenna attached to
818 the center of one end of the board is about 7 inches long. Two
819 wires for the power switch are connected to holes in the
820 middle of the board. Screw terminals for the e-matches for
821 apogee and main ejection charges depart from the other end of
822 the board, meaning an ideal “simple” avionics bay for TeleMini
823 should have at least 9 inches of interior length.
826 <title>TeleMini v1.0 Screw Terminals</title>
828 TeleMini v1.0 has four screw terminals on the end of the
829 board opposite the telemetry antenna. Two are for the apogee
830 and two are for main igniter circuits. There are also wires
831 soldered to the board for the power switch. Using the
832 picture above and starting from the top for the terminals
833 and from the left for the power switch wires, the
834 connections are as follows:
837 <title>TeleMini v1.0 Connections</title>
838 <?dbfo keep-together="always"?>
839 <tgroup cols='3' align='center' colsep='1' rowsep='1'>
840 <colspec align='center' colwidth='*' colname='Pin #'/>
841 <colspec align='center' colwidth='2*' colname='Pin Name'/>
842 <colspec align='left' colwidth='5*' colname='Description'/>
845 <entry align='center'>Terminal #</entry>
846 <entry align='center'>Terminal Name</entry>
847 <entry align='center'>Description</entry>
853 <entry>Apogee -</entry>
854 <entry>Apogee pyro channel connection to pyro circuit</entry>
858 <entry>Apogee +</entry>
859 <entry>Apogee pyro channel common connection to battery +</entry>
863 <entry>Main -</entry>
864 <entry>Main pyro channel connection to pyro circuit</entry>
868 <entry>Main +</entry>
869 <entry>Main pyro channel common connection to battery +</entry>
873 <entry>Switch Output</entry>
874 <entry>Switch connection to flight computer</entry>
878 <entry>Switch Input</entry>
879 <entry>Switch connection to positive battery terminal</entry>
886 <title>Using a Separate Pyro Battery with TeleMini v1.0</title>
888 As described above, using an external pyro battery involves
889 connecting the negative battery terminal to the flight
890 computer ground, connecting the positive battery terminal to
891 one of the igniter leads and connecting the other igniter
892 lead to the per-channel pyro circuit connection. Because
893 there is no solid ground connection to use on TeleMini, this
897 The only available ground connection on TeleMini v1.0 are
898 the two mounting holes next to the telemetry
899 antenna. Somehow connect a small piece of wire to one of
900 those holes and hook it to the negative pyro battery terminal.
903 Connecting the positive battery terminal to the pyro
904 charges must be done separate from TeleMini v1.0, by soldering
905 them together or using some other connector.
908 The other lead from each pyro charge is then inserted into
909 the appropriate per-pyro channel screw terminal (terminal 3 for the
910 Main charge, terminal 1 for the Apogee charge).
914 <title>Using an Active Switch with TeleMini v1.0</title>
916 As explained above, an external active switch requires three
917 connections, one to the positive battery terminal, one to
918 the flight computer positive input and one to ground. Again,
919 because TeleMini doesn't have any good ground connection,
920 this is not recommended.
923 The positive battery terminal is available on the Right
924 power switch wire, the positive flight computer input is on
925 the left power switch wire. Hook a lead to either of the
926 mounting holes for a ground connection.
931 <title>TeleMini v2.0</title>
935 <imagedata fileref="telemini-v2-top.jpg" width="5.5in" scalefit="1"/>
940 TeleMini v2.0 is 0.8 inches by 1½ inches. It adds more
941 on-board data logging memory, a built-in USB connector and
942 screw terminals for the battery and power switch. The larger
943 board fits in a 24mm coupler. There's also a battery connector
944 for a LiPo battery if you want to use one of those.
947 <title>TeleMini v2.0 Screw Terminals</title>
949 TeleMini v2.0 has two sets of four screw terminals on the end of the
950 board opposite the telemetry antenna. Using the picture
951 above, the top four have connections for the main pyro
952 circuit and an external battery and the bottom four have
953 connections for the apogee pyro circuit and the power
954 switch. Counting from the left, the connections are as follows:
957 <title>TeleMini v2.0 Connections</title>
958 <?dbfo keep-together="always"?>
959 <tgroup cols='3' align='center' colsep='1' rowsep='1'>
960 <colspec align='center' colwidth='*' colname='Pin #'/>
961 <colspec align='center' colwidth='2*' colname='Pin Name'/>
962 <colspec align='left' colwidth='5*' colname='Description'/>
965 <entry align='center'>Terminal #</entry>
966 <entry align='center'>Terminal Name</entry>
967 <entry align='center'>Description</entry>
973 <entry>Main -</entry>
974 <entry>Main pyro channel connection to pyro circuit</entry>
978 <entry>Main +</entry>
979 <entry>Main pyro channel common connection to battery +</entry>
983 <entry>Battery +</entry>
984 <entry>Positive external battery terminal</entry>
988 <entry>Battery -</entry>
989 <entry>Negative external battery terminal</entry>
992 <entry>Bottom 1</entry>
993 <entry>Apogee -</entry>
994 <entry>Apogee pyro channel connection to pyro circuit</entry>
997 <entry>Bottom 2</entry>
998 <entry>Apogee +</entry>
999 <entry>Apogee pyro channel common connection to
1003 <entry>Bottom 3</entry>
1004 <entry>Switch Output</entry>
1005 <entry>Switch connection to flight computer</entry>
1008 <entry>Bottom 4</entry>
1009 <entry>Switch Input</entry>
1010 <entry>Switch connection to positive battery terminal</entry>
1017 <title>Using a Separate Pyro Battery with TeleMini v2.0</title>
1019 As described above, using an external pyro battery involves
1020 connecting the negative battery terminal to the flight
1021 computer ground, connecting the positive battery terminal to
1022 one of the igniter leads and connecting the other igniter
1023 lead to the per-channel pyro circuit connection.
1026 To connect the negative pyro battery terminal to TeleMini
1027 ground, connect it to the negative external battery
1028 connection, top terminal 4.
1031 Connecting the positive battery terminal to the pyro
1032 charges must be done separate from TeleMini v2.0, by soldering
1033 them together or using some other connector.
1036 The other lead from each pyro charge is then inserted into
1037 the appropriate per-pyro channel screw terminal (top
1038 terminal 1 for the Main charge, bottom terminal 1 for the
1043 <title>Using an Active Switch with TeleMini v2.0</title>
1045 As explained above, an external active switch requires three
1046 connections, one to the positive battery terminal, one to
1047 the flight computer positive input and one to ground. Use
1048 the negative external battery connection, top terminal 4 for
1052 The positive battery terminal is available on bottom
1053 terminal 4, the positive flight computer input is on the
1059 <title>EasyMini</title>
1063 <imagedata fileref="easymini-top.jpg" width="5.5in" scalefit="1"/>
1068 EasyMini is built on a 0.8 inch by 1½ inch circuit board. It's
1069 designed to fit in a 24mm coupler tube. The connectors and
1070 screw terminals match TeleMini v2.0, so you can easily swap between
1071 EasyMini and TeleMini.
1074 <title>EasyMini Screw Terminals</title>
1076 EasyMini has two sets of four screw terminals on the end of the
1077 board opposite the telemetry antenna. Using the picture
1078 above, the top four have connections for the main pyro
1079 circuit and an external battery and the bottom four have
1080 connections for the apogee pyro circuit and the power
1081 switch. Counting from the left, the connections are as follows:
1084 <title>EasyMini Connections</title>
1085 <?dbfo keep-together="always"?>
1086 <tgroup cols='3' align='center' colsep='1' rowsep='1'>
1087 <colspec align='center' colwidth='*' colname='Pin #'/>
1088 <colspec align='center' colwidth='2*' colname='Pin Name'/>
1089 <colspec align='left' colwidth='5*' colname='Description'/>
1092 <entry align='center'>Terminal #</entry>
1093 <entry align='center'>Terminal Name</entry>
1094 <entry align='center'>Description</entry>
1099 <entry>Top 1</entry>
1100 <entry>Main -</entry>
1101 <entry>Main pyro channel connection to pyro circuit</entry>
1104 <entry>Top 2</entry>
1105 <entry>Main +</entry>
1106 <entry>Main pyro channel common connection to battery +</entry>
1109 <entry>Top 3</entry>
1110 <entry>Battery +</entry>
1111 <entry>Positive external battery terminal</entry>
1114 <entry>Top 4</entry>
1115 <entry>Battery -</entry>
1116 <entry>Negative external battery terminal</entry>
1119 <entry>Bottom 1</entry>
1120 <entry>Apogee -</entry>
1121 <entry>Apogee pyro channel connection to pyro circuit</entry>
1124 <entry>Bottom 2</entry>
1125 <entry>Apogee +</entry>
1126 <entry>Apogee pyro channel common connection to
1130 <entry>Bottom 3</entry>
1131 <entry>Switch Output</entry>
1132 <entry>Switch connection to flight computer</entry>
1135 <entry>Bottom 4</entry>
1136 <entry>Switch Input</entry>
1137 <entry>Switch connection to positive battery terminal</entry>
1144 <title>Using a Separate Pyro Battery with EasyMini</title>
1146 As described above, using an external pyro battery involves
1147 connecting the negative battery terminal to the flight
1148 computer ground, connecting the positive battery terminal to
1149 one of the igniter leads and connecting the other igniter
1150 lead to the per-channel pyro circuit connection.
1153 To connect the negative pyro battery terminal to TeleMini
1154 ground, connect it to the negative external battery
1155 connection, top terminal 4.
1158 Connecting the positive battery terminal to the pyro
1159 charges must be done separate from EasyMini, by soldering
1160 them together or using some other connector.
1163 The other lead from each pyro charge is then inserted into
1164 the appropriate per-pyro channel screw terminal (top
1165 terminal 1 for the Main charge, bottom terminal 1 for the
1170 <title>Using an Active Switch with EasyMini</title>
1172 As explained above, an external active switch requires three
1173 connections, one to the positive battery terminal, one to
1174 the flight computer positive input and one to ground. Use
1175 the negative external battery connection, top terminal 4 for
1179 The positive battery terminal is available on bottom
1180 terminal 4, the positive flight computer input is on the
1186 <title>TeleMega</title>
1190 <imagedata fileref="telemega-v1.0-top.jpg" width="5.5in" scalefit="1"/>
1195 TeleMega is a 1¼ inch by 3¼ inch circuit board. It was
1196 designed to easily fit in a 38mm coupler. Like TeleMetrum,
1197 TeleMega has an accelerometer and so it must be mounted so that
1198 the board is aligned with the flight axis. It can be mounted
1199 either antenna up or down.
1202 <title>TeleMega Screw Terminals</title>
1204 TeleMega has two sets of nine screw terminals on the end of
1205 the board opposite the telemetry antenna. They are as follows:
1208 <title>TeleMega Screw Terminals</title>
1209 <?dbfo keep-together="always"?>
1210 <tgroup cols='3' align='center' colsep='1' rowsep='1'>
1211 <colspec align='center' colwidth='*' colname='Pin #'/>
1212 <colspec align='center' colwidth='2*' colname='Pin Name'/>
1213 <colspec align='left' colwidth='5*' colname='Description'/>
1216 <entry align='center'>Terminal #</entry>
1217 <entry align='center'>Terminal Name</entry>
1218 <entry align='center'>Description</entry>
1223 <entry>Top 1</entry>
1224 <entry>Switch Input</entry>
1225 <entry>Switch connection to positive battery terminal</entry>
1228 <entry>Top 2</entry>
1229 <entry>Switch Output</entry>
1230 <entry>Switch connection to flight computer</entry>
1233 <entry>Top 3</entry>
1235 <entry>Ground connection for use with external active switch</entry>
1238 <entry>Top 4</entry>
1239 <entry>Main -</entry>
1240 <entry>Main pyro channel connection to pyro circuit</entry>
1243 <entry>Top 5</entry>
1244 <entry>Main +</entry>
1245 <entry>Main pyro channel common connection to battery +</entry>
1248 <entry>Top 6</entry>
1249 <entry>Apogee -</entry>
1250 <entry>Apogee pyro channel connection to pyro circuit</entry>
1253 <entry>Top 7</entry>
1254 <entry>Apogee +</entry>
1255 <entry>Apogee pyro channel common connection to battery +</entry>
1258 <entry>Top 8</entry>
1260 <entry>D pyro channel connection to pyro circuit</entry>
1263 <entry>Top 9</entry>
1265 <entry>D pyro channel common connection to battery +</entry>
1268 <entry>Bottom 1</entry>
1270 <entry>Ground connection for negative pyro battery terminal</entry>
1273 <entry>Bottom 2</entry>
1275 <entry>Positive pyro battery terminal</entry>
1278 <entry>Bottom 3</entry>
1281 Power switch output. Use to connect main battery to
1286 <entry>Bottom 4</entry>
1288 <entry>A pyro channel connection to pyro circuit</entry>
1291 <entry>Bottom 5</entry>
1293 <entry>A pyro channel common connection to battery +</entry>
1296 <entry>Bottom 6</entry>
1298 <entry>B pyro channel connection to pyro circuit</entry>
1301 <entry>Bottom 7</entry>
1303 <entry>B pyro channel common connection to battery +</entry>
1306 <entry>Bottom 8</entry>
1308 <entry>C pyro channel connection to pyro circuit</entry>
1311 <entry>Bottom 9</entry>
1313 <entry>C pyro channel common connection to battery +</entry>
1320 <title>Using a Separate Pyro Battery with TeleMega</title>
1322 TeleMega provides explicit support for an external pyro
1323 battery. All that is required is to remove the jumper
1324 between the lipo terminal (Bottom 3) and the pyro terminal
1325 (Bottom 2). Then hook the negative pyro battery terminal to ground
1326 (Bottom 1) and the positive pyro battery to the pyro battery
1327 input (Bottom 2). You can then use the existing pyro screw
1328 terminals to hook up all of the pyro charges.
1332 <title>Using Only One Battery With TeleMega</title>
1334 Because TeleMega has built-in support for a separate pyro
1335 battery, if you want to fly with just one battery running
1336 both the computer and firing the charges, you need to
1337 connect the flight computer battery to the pyro
1338 circuit. TeleMega has two screw terminals for this—hook a
1339 wire from the Lipo terminal (Bottom 3) to the Pyro terminal
1344 <title>Using an Active Switch with TeleMega</title>
1346 As explained above, an external active switch requires three
1347 connections, one to the positive battery terminal, one to
1348 the flight computer positive input and one to ground.
1351 The positive battery terminal is available on Top terminal
1352 1, the positive flight computer input is on Top terminal
1353 2. Ground is on Top terminal 3.
1358 <title>Flight Data Recording</title>
1360 Each flight computer logs data at 100 samples per second
1361 during ascent and 10 samples per second during descent, except
1362 for TeleMini v1.0, which records ascent at 10 samples per
1363 second and descent at 1 sample per second. Data are logged to
1364 an on-board flash memory part, which can be partitioned into
1365 several equal-sized blocks, one for each flight.
1368 <title>Data Storage on Altus Metrum altimeters</title>
1369 <?dbfo keep-together="always"?>
1370 <tgroup cols='4' align='center' colsep='1' rowsep='1'>
1371 <colspec align='center' colwidth='*' colname='Device'/>
1372 <colspec align='center' colwidth='*' colname='Bytes per sample'/>
1373 <colspec align='center' colwidth='*' colname='Total storage'/>
1374 <colspec align='center' colwidth='*' colname='Minutes of
1378 <entry align='center'>Device</entry>
1379 <entry align='center'>Bytes per Sample</entry>
1380 <entry align='center'>Total Storage</entry>
1381 <entry align='center'>Minutes at Full Rate</entry>
1386 <entry>TeleMetrum v1.0</entry>
1392 <entry>TeleMetrum v1.1 v1.2</entry>
1398 <entry>TeleMetrum v2.0</entry>
1404 <entry>TeleMini v1.0</entry>
1410 <entry>TeleMini v2.0</entry>
1416 <entry>EasyMini</entry>
1422 <entry>TeleMega</entry>
1431 The on-board flash is partitioned into separate flight logs,
1432 each of a fixed maximum size. Increase the maximum size of
1433 each log and you reduce the number of flights that can be
1434 stored. Decrease the size and you can store more flights.
1437 Configuration data is also stored in the flash memory on
1438 TeleMetrum v1.x, TeleMini and EasyMini. This consumes 64kB
1439 of flash space. This configuration space is not available
1440 for storing flight log data. TeleMetrum v2.0 and TeleMega
1441 store configuration data in a bit of eeprom available within
1442 the processor chip, leaving that space available in flash for
1446 To compute the amount of space needed for a single flight, you
1447 can multiply the expected ascent time (in seconds) by 100
1448 times bytes-per-sample, multiply the expected descent time (in
1449 seconds) by 10 times the bytes per sample and add the two
1450 together. That will slightly under-estimate the storage (in
1451 bytes) needed for the flight. For instance, a TeleMetrum v2.0 flight spending
1452 20 seconds in ascent and 150 seconds in descent will take
1453 about (20 * 1600) + (150 * 160) = 56000 bytes of storage. You
1454 could store dozens of these flights in the on-board flash.
1457 The default size allows for several flights on each flight
1458 computer, except for TeleMini v1.0, which only holds data for a
1459 single flight. You can adjust the size.
1462 Altus Metrum flight computers will not overwrite existing
1463 flight data, so be sure to download flight data and erase it
1464 from the flight computer before it fills up. The flight
1465 computer will still successfully control the flight even if it
1466 cannot log data, so the only thing you will lose is the data.
1470 <title>Installation</title>
1472 A typical installation involves attaching
1473 only a suitable battery, a single pole switch for
1474 power on/off, and two pairs of wires connecting e-matches for the
1475 apogee and main ejection charges. All Altus Metrum products are
1476 designed for use with single-cell batteries with 3.7 volts
1477 nominal. TeleMini v2.0 and EasyMini may also be used with other
1478 batteries as long as they supply between 4 and 12 volts.
1481 The battery connectors are a standard 2-pin JST connector and
1482 match batteries sold by Spark Fun. These batteries are
1483 single-cell Lithium Polymer batteries that nominally provide 3.7
1484 volts. Other vendors sell similar batteries for RC aircraft
1485 using mating connectors, however the polarity for those is
1486 generally reversed from the batteries used by Altus Metrum
1487 products. In particular, the Tenergy batteries supplied for use
1488 in Featherweight flight computers are not compatible with Altus
1489 Metrum flight computers or battery chargers. <emphasis>Check
1490 polarity and voltage before connecting any battery not purchased
1491 from Altus Metrum or Spark Fun.</emphasis>
1494 By default, we use the unregulated output of the battery directly
1495 to fire ejection charges. This works marvelously with standard
1496 low-current e-matches like the J-Tek from MJG Technologies, and with
1497 Quest Q2G2 igniters. However, if you want or need to use a separate
1498 pyro battery, check out the “External Pyro Battery” section in this
1499 manual for instructions on how to wire that up. The altimeters are
1500 designed to work with an external pyro battery of no more than 15 volts.
1503 Ejection charges are wired directly to the screw terminal block
1504 at the aft end of the altimeter. You'll need a very small straight
1505 blade screwdriver for these screws, such as you might find in a
1506 jeweler's screwdriver set.
1509 Except for TeleMini v1.0, the flight computers also use the
1510 screw terminal block for the power switch leads. On TeleMini v1.0,
1511 the power switch leads are soldered directly to the board and
1512 can be connected directly to a switch.
1515 For most air-frames, the integrated antennas are more than
1516 adequate. However, if you are installing in a carbon-fiber or
1517 metal electronics bay which is opaque to RF signals, you may need to
1518 use off-board external antennas instead. In this case, you can
1519 replace the stock UHF antenna wire with an edge-launched SMA connector,
1520 and, on TeleMetrum v1, you can unplug the integrated GPS
1521 antenna and select an appropriate off-board GPS antenna with
1522 cable terminating in a U.FL connector.
1527 <title>System Operation</title>
1529 <title>Firmware Modes </title>
1531 The AltOS firmware build for the altimeters has two
1532 fundamental modes, “idle” and “flight”. Which of these modes
1533 the firmware operates in is determined at start up time. For
1534 TeleMetrum and TeleMega, which have accelerometers, the mode is
1535 controlled by the orientation of the
1536 rocket (well, actually the board, of course...) at the time
1537 power is switched on. If the rocket is “nose up”, then
1538 the flight computer assumes it's on a rail or rod being prepared for
1539 launch, so the firmware chooses flight mode. However, if the
1540 rocket is more or less horizontal, the firmware instead enters
1541 idle mode. Since TeleMini v2.0 and EasyMini don't have an
1542 accelerometer we can use to determine orientation, “idle” mode
1543 is selected if the board is connected via USB to a computer,
1544 otherwise the board enters “flight” mode. TeleMini v1.0
1545 selects “idle” mode if it receives a command packet within the
1546 first five seconds of operation.
1549 At power on, the altimeter will beep out the battery voltage
1550 to the nearest tenth of a volt. Each digit is represented by
1551 a sequence of short “dit” beeps, with a pause between
1552 digits. A zero digit is represented with one long “dah”
1553 beep. Then there will be a short pause while the altimeter
1554 completes initialization and self test, and decides which mode
1558 Here's a short summary of all of the modes and the beeping (or
1559 flashing, in the case of TeleMini v1) that accompanies each
1560 mode. In the description of the beeping pattern, “dit” means a
1561 short beep while "dah" means a long beep (three times as
1562 long). “Brap” means a long dissonant tone.
1564 <title>AltOS Modes</title>
1565 <?dbfo keep-together="always"?>
1566 <tgroup cols='4' align='center' colsep='1' rowsep='1'>
1567 <colspec align='center' colwidth='*' colname='Mode Name'/>
1568 <colspec align='center' colwidth='*' colname='Letter'/>
1569 <colspec align='center' colwidth='*' colname='Beeps'/>
1570 <colspec align='center' colwidth='*' colname='Description'/>
1573 <entry>Mode Name</entry>
1574 <entry>Abbreviation</entry>
1575 <entry>Beeps</entry>
1576 <entry>Description</entry>
1581 <entry>Startup</entry>
1583 <entry>battery voltage in decivolts</entry>
1586 Calibrating sensors, detecting orientation.
1593 <entry>dit dit</entry>
1596 Ready to accept commands over USB or radio link.
1603 <entry>dit dah dah dit</entry>
1606 Waiting for launch. Not listening for commands.
1611 <entry>Boost</entry>
1613 <entry>dah dit dit dit</entry>
1616 Accelerating upwards.
1623 <entry>dit dit dah dit</entry>
1626 Decelerating, but moving faster than 200m/s.
1631 <entry>Coast</entry>
1633 <entry>dah dit dah dit</entry>
1636 Decelerating, moving slower than 200m/s
1641 <entry>Drogue</entry>
1643 <entry>dah dit dit</entry>
1646 Descending after apogee. Above main height.
1653 <entry>dah dah</entry>
1656 Descending. Below main height.
1661 <entry>Landed</entry>
1663 <entry>dit dah dit dit</entry>
1666 Stable altitude for at least ten seconds.
1671 <entry>Sensor error</entry>
1673 <entry>dah dit dit dah</entry>
1676 Error detected during sensor calibration.
1685 In flight or “pad” mode, the altimeter engages the flight
1686 state machine, goes into transmit-only mode to send telemetry,
1687 and waits for launch to be detected. Flight mode is indicated
1688 by an “di-dah-dah-dit” (“P” for pad) on the beeper or lights,
1689 followed by beeps or flashes indicating the state of the
1690 pyrotechnic igniter continuity. One beep/flash indicates
1691 apogee continuity, two beeps/flashes indicate main continuity,
1692 three beeps/flashes indicate both apogee and main continuity,
1693 and one longer “brap” sound which is made by rapidly
1694 alternating between two tones indicates no continuity. For a
1695 dual deploy flight, make sure you're getting three beeps or
1696 flashes before launching! For apogee-only or motor eject
1697 flights, do what makes sense.
1700 If idle mode is entered, you will hear an audible “di-dit” or
1701 see two short flashes (“I” for idle), and the flight state
1702 machine is disengaged, thus no ejection charges will fire.
1703 The altimeters also listen for the radio link when in idle
1704 mode for requests sent via TeleDongle. Commands can be issued
1705 in idle mode over either USB or the radio link
1706 equivalently. TeleMini v1.0 only has the radio link. Idle
1707 mode is useful for configuring the altimeter, for extracting
1708 data from the on-board storage chip after flight, and for
1709 ground testing pyro charges.
1712 In “Idle” and “Pad” modes, once the mode indication
1713 beeps/flashes and continuity indication has been sent, if
1714 there is no space available to log the flight in on-board
1715 memory, the flight computer will emit a warbling tone (much
1716 slower than the “no continuity tone”)
1719 Here's a summary of all of the “pad” and “idle” mode indications.
1721 <title>Pad/Idle Indications</title>
1722 <?dbfo keep-together="always"?>
1723 <tgroup cols='3' align='center' colsep='1' rowsep='1'>
1724 <colspec align='center' colwidth='*' colname='Name'/>
1725 <colspec align='center' colwidth='*' colname='Beeps'/>
1726 <colspec align='center' colwidth='*' colname='Description'/>
1730 <entry>Beeps</entry>
1731 <entry>Description</entry>
1736 <entry>Neither</entry>
1740 No continuity detected on either apogee or main
1746 <entry>Apogee</entry>
1750 Continuity detected only on apogee igniter.
1756 <entry>dit dit</entry>
1759 Continuity detected only on main igniter.
1765 <entry>dit dit dit</entry>
1768 Continuity detected on both igniters.
1773 <entry>Storage Full</entry>
1774 <entry>warble</entry>
1777 On-board data logging storage is full. This will
1778 not prevent the flight computer from safely
1779 controlling the flight or transmitting telemetry
1780 signals, but no record of the flight will be
1781 stored in on-board flash.
1790 Once landed, the flight computer will signal that by emitting
1791 the “Landed” sound described above, after which it will beep
1792 out the apogee height (in meters). Each digit is represented
1793 by a sequence of short “dit” beeps, with a pause between
1794 digits. A zero digit is represented with one long “dah”
1795 beep. The flight computer will continue to report landed mode
1796 and beep out the maximum height until turned off.
1799 One “neat trick” of particular value when TeleMetrum or TeleMega are used with
1800 very large air-frames, is that you can power the board up while the
1801 rocket is horizontal, such that it comes up in idle mode. Then you can
1802 raise the air-frame to launch position, and issue a 'reset' command
1803 via TeleDongle over the radio link to cause the altimeter to reboot and
1804 come up in flight mode. This is much safer than standing on the top
1805 step of a rickety step-ladder or hanging off the side of a launch
1806 tower with a screw-driver trying to turn on your avionics before
1807 installing igniters!
1810 TeleMini v1.0 is configured solely via the radio link. Of course, that
1811 means you need to know the TeleMini radio configuration values
1812 or you won't be able to communicate with it. For situations
1813 when you don't have the radio configuration values, TeleMini v1.0
1814 offers an 'emergency recovery' mode. In this mode, TeleMini is
1815 configured as follows:
1819 Sets the radio frequency to 434.550MHz
1824 Sets the radio calibration back to the factory value.
1829 Sets the callsign to N0CALL
1834 Does not go to 'pad' mode after five seconds.
1840 To get into 'emergency recovery' mode, first find the row of
1841 four small holes opposite the switch wiring. Using a short
1842 piece of small gauge wire, connect the outer two holes
1843 together, then power TeleMini up. Once the red LED is lit,
1844 disconnect the wire and the board should signal that it's in
1845 'idle' mode after the initial five second startup period.
1851 TeleMetrum and TeleMega include a complete GPS receiver. A
1852 complete explanation of how GPS works is beyond the scope of
1853 this manual, but the bottom line is that the GPS receiver
1854 needs to lock onto at least four satellites to obtain a solid
1855 3 dimensional position fix and know what time it is.
1858 The flight computers provide backup power to the GPS chip any time a
1859 battery is connected. This allows the receiver to “warm start” on
1860 the launch rail much faster than if every power-on were a GPS
1861 “cold start”. In typical operations, powering up
1862 on the flight line in idle mode while performing final air-frame
1863 preparation will be sufficient to allow the GPS receiver to cold
1864 start and acquire lock. Then the board can be powered down during
1865 RSO review and installation on a launch rod or rail. When the board
1866 is turned back on, the GPS system should lock very quickly, typically
1867 long before igniter installation and return to the flight line are
1872 <title>Controlling An Altimeter Over The Radio Link</title>
1874 One of the unique features of the Altus Metrum system is the
1875 ability to create a two way command link between TeleDongle
1876 and an altimeter using the digital radio transceivers
1877 built into each device. This allows you to interact with the
1878 altimeter from afar, as if it were directly connected to the
1882 Any operation which can be performed with a flight computer can
1883 either be done with the device directly connected to the
1884 computer via the USB cable, or through the radio
1885 link. TeleMini v1.0 doesn't provide a USB connector and so it is
1886 always communicated with over radio. Select the appropriate
1887 TeleDongle device when the list of devices is presented and
1888 AltosUI will interact with an altimeter over the radio link.
1891 One oddity in the current interface is how AltosUI selects the
1892 frequency for radio communications. Instead of providing
1893 an interface to specifically configure the frequency, it uses
1894 whatever frequency was most recently selected for the target
1895 TeleDongle device in Monitor Flight mode. If you haven't ever
1896 used that mode with the TeleDongle in question, select the
1897 Monitor Flight button from the top level UI, and pick the
1898 appropriate TeleDongle device. Once the flight monitoring
1899 window is open, select the desired frequency and then close it
1900 down again. All radio communications will now use that frequency.
1905 Save Flight Data—Recover flight data from the rocket without
1911 Configure altimeter apogee delays, main deploy heights
1912 and additional pyro event conditions
1913 to respond to changing launch conditions. You can also
1914 'reboot' the altimeter. Use this to remotely enable the
1915 flight computer by turning TeleMetrum or TeleMega on in “idle” mode,
1916 then once the air-frame is oriented for launch, you can
1917 reboot the altimeter and have it restart in pad mode
1918 without having to climb the scary ladder.
1923 Fire Igniters—Test your deployment charges without snaking
1924 wires out through holes in the air-frame. Simply assemble the
1925 rocket as if for flight with the apogee and main charges
1926 loaded, then remotely command the altimeter to fire the
1932 Operation over the radio link for configuring an altimeter, ground
1933 testing igniters, and so forth uses the same RF frequencies as flight
1934 telemetry. To configure the desired TeleDongle frequency, select
1935 the monitor flight tab, then use the frequency selector and
1936 close the window before performing other desired radio operations.
1939 The flight computers only enable radio commanding in 'idle' mode.
1940 TeleMetrum and TeleMega use the accelerometer to detect which orientation they
1941 start up in, so make sure you have the flight computer lying horizontally when you turn
1942 it on. Otherwise, it will start in 'pad' mode ready for
1943 flight, and will not be listening for command packets from TeleDongle.
1946 TeleMini listens for a command packet for five seconds after
1947 first being turned on, if it doesn't hear anything, it enters
1948 'pad' mode, ready for flight and will no longer listen for
1949 command packets. The easiest way to connect to TeleMini is to
1950 initiate the command and select the TeleDongle device. At this
1951 point, the TeleDongle will be attempting to communicate with
1952 the TeleMini. Now turn TeleMini on, and it should immediately
1953 start communicating with the TeleDongle and the desired
1954 operation can be performed.
1957 You can monitor the operation of the radio link by watching the
1958 lights on the devices. The red LED will flash each time a packet
1959 is transmitted, while the green LED will light up on TeleDongle when
1960 it is waiting to receive a packet from the altimeter.
1964 <title>Ground Testing </title>
1966 An important aspect of preparing a rocket using electronic deployment
1967 for flight is ground testing the recovery system. Thanks
1968 to the bi-directional radio link central to the Altus Metrum system,
1969 this can be accomplished in a TeleMega, TeleMetrum or TeleMini equipped rocket
1970 with less work than you may be accustomed to with other systems. It
1974 Just prep the rocket for flight, then power up the altimeter
1975 in “idle” mode (placing air-frame horizontal for TeleMetrum or TeleMega, or
1976 selecting the Configure Altimeter tab for TeleMini). This will cause
1977 the firmware to go into “idle” mode, in which the normal flight
1978 state machine is disabled and charges will not fire without
1979 manual command. You can now command the altimeter to fire the apogee
1980 or main charges from a safe distance using your computer and
1981 TeleDongle and the Fire Igniter tab to complete ejection testing.
1985 <title>Radio Link </title>
1987 Our flight computers all incorporate an RF transceiver, but
1988 it's not a full duplex system... each end can only be transmitting or
1989 receiving at any given moment. So we had to decide how to manage the
1993 By design, the altimeter firmware listens for the radio link when
1994 it's in “idle mode”, which
1995 allows us to use the radio link to configure the rocket, do things like
1996 ejection tests, and extract data after a flight without having to
1997 crack open the air-frame. However, when the board is in “flight
1998 mode”, the altimeter only
1999 transmits and doesn't listen at all. That's because we want to put
2000 ultimate priority on event detection and getting telemetry out of
2002 the radio in case the rocket crashes and we aren't able to extract
2006 We don't generally use a 'normal packet radio' mode like APRS
2007 because they're just too inefficient. The GFSK modulation we
2008 use is FSK with the base-band pulses passed through a Gaussian
2009 filter before they go into the modulator to limit the
2010 transmitted bandwidth. When combined with forward error
2011 correction and interleaving, this allows us to have a very
2012 robust 19.2 kilobit data link with only 10-40 milliwatts of
2013 transmit power, a whip antenna in the rocket, and a hand-held
2014 Yagi on the ground. We've had flights to above 21k feet AGL
2015 with great reception, and calculations suggest we should be
2016 good to well over 40k feet AGL with a 5-element yagi on the
2017 ground with our 10mW units and over 100k feet AGL with the
2018 40mW devices. We hope to fly boards to higher altitudes over
2019 time, and would of course appreciate customer feedback on
2020 performance in higher altitude flights!
2026 TeleMetrum v2.0 and TeleMega can send APRS if desired, and the
2027 interval between APRS packets can be configured. As each APRS
2028 packet takes a full second to transmit, we recommend an
2029 interval of at least 5 seconds to avoid consuming too much
2030 battery power or radio channel bandwidth. You can configure
2031 the APRS interval using AltosUI; that process is described in
2032 the Configure Altimeter section of the AltosUI chapter.
2035 AltOS uses the APRS compressed position report data format,
2036 which provides for higher position precision and shorter
2037 packets than the original APRS format. It also includes
2038 altitude data, which is invaluable when tracking rockets. We
2039 haven't found a receiver which doesn't handle compressed
2040 positions, but it's just possible that you have one, so if you
2041 have an older device that can receive the raw packets but
2042 isn't displaying position information, it's possible that this
2046 The APRS packet format includes a comment field that can have
2047 arbitrary text in it. AltOS uses this to send status
2048 information about the flight computer. It sends four fields as
2049 shown in the following table.
2052 <title>Altus Metrum APRS Comments</title>
2053 <?dbfo keep-together="always"?>
2054 <tgroup cols='3' align='center' colsep='1' rowsep='1'>
2055 <colspec align='center' colwidth='*' colname='Field'/>
2056 <colspec align='center' colwidth='*' colname='Example'/>
2057 <colspec align='center' colwidth='4*' colname='Description'/>
2060 <entry align='center'>Field</entry>
2061 <entry align='center'>Example</entry>
2062 <entry align='center'>Description</entry>
2069 <entry>GPS Status U for unlocked, L for locked</entry>
2074 <entry>Number of Satellites in View</entry>
2079 <entry>Altimeter Battery Voltage</entry>
2084 <entry>Apogee Igniter Voltage</entry>
2089 <entry>Main Igniter Voltage</entry>
2095 Here's an example of an APRS comment showing GPS lock with 6
2096 satellites in view, a primary battery at 4.0V, and
2097 apogee and main igniters both at 3.7V.
2103 Make sure your primary battery is above 3.8V, any connected
2104 igniters are above 3.5V and GPS is locked with at least 5 or 6
2105 satellites in view before flying. If GPS is switching between
2106 L and U regularly, then it doesn't have a good lock and you
2107 should wait until it becomes stable.
2110 If the GPS receiver loses lock, the APRS data transmitted will
2111 contain the last position for which GPS lock was
2112 available. You can tell that this has happened by noticing
2113 that the GPS status character switches from 'L' to 'U'. Before
2114 GPS has locked, APRS will transmit zero for latitude,
2115 longitude and altitude.
2119 <title>Configurable Parameters</title>
2121 Configuring an Altus Metrum altimeter for flight is very
2122 simple. Even on our baro-only TeleMini and EasyMini boards,
2123 the use of a Kalman filter means there is no need to set a
2124 “mach delay”. The few configurable parameters can all be set
2125 using AltosUI over USB or or radio link via TeleDongle. Read
2126 the Configure Altimeter section in the AltosUI chapter below
2127 for more information.
2130 <title>Radio Frequency</title>
2132 Altus Metrum boards support radio frequencies in the 70cm
2133 band. By default, the configuration interface provides a
2134 list of 10 “standard” frequencies in 100kHz channels starting at
2135 434.550MHz. However, the firmware supports use of
2136 any 50kHz multiple within the 70cm band. At any given
2137 launch, we highly recommend coordinating when and by whom each
2138 frequency will be used to avoid interference. And of course, both
2139 altimeter and TeleDongle must be configured to the same
2140 frequency to successfully communicate with each other.
2144 <title>Callsign</title>
2146 This sets the callsign used for telemetry, APRS and the
2147 packet link. For telemetry and APRS, this is used to
2148 identify the device. For the packet link, the callsign must
2149 match that configured in AltosUI or the link will not
2150 work. This is to prevent accidental configuration of another
2151 Altus Metrum flight computer operating on the same frequency nearby.
2155 <title>Telemetry/RDF/APRS Enable</title>
2157 You can completely disable the radio while in flight, if
2158 necessary. This doesn't disable the packet link in idle
2163 <title>APRS Interval</title>
2165 This selects how often APRS packets are transmitted. Set
2166 this to zero to disable APRS without also disabling the
2167 regular telemetry and RDF transmissions. As APRS takes a
2168 full second to transmit a single position report, we
2169 recommend sending packets no more than once every 5 seconds.
2173 <title>Apogee Delay</title>
2175 Apogee delay is the number of seconds after the altimeter detects flight
2176 apogee that the drogue charge should be fired. In most cases, this
2177 should be left at the default of 0. However, if you are flying
2178 redundant electronics such as for an L3 certification, you may wish
2179 to set one of your altimeters to a positive delay so that both
2180 primary and backup pyrotechnic charges do not fire simultaneously.
2183 The Altus Metrum apogee detection algorithm fires exactly at
2184 apogee. If you are also flying an altimeter like the
2185 PerfectFlite MAWD, which only supports selecting 0 or 1
2186 seconds of apogee delay, you may wish to set the MAWD to 0
2187 seconds delay and set the TeleMetrum to fire your backup 2
2188 or 3 seconds later to avoid any chance of both charges
2189 firing simultaneously. We've flown several air-frames this
2190 way quite happily, including Keith's successful L3 cert.
2194 <title>Apogee Lockout</title>
2196 Apogee lockout is the number of seconds after boost where
2197 the flight computer will not fire the apogee charge, even if
2198 the rocket appears to be at apogee. This is often called
2199 'Mach Delay', as it is intended to prevent a flight computer
2200 from unintentionally firing apogee charges due to the pressure
2201 spike that occurrs across a mach transition. Altus Metrum
2202 flight computers include a Kalman filter which is not fooled
2203 by this sharp pressure increase, and so this setting should
2204 be left at the default value of zero to disable it.
2208 <title>Main Deployment Altitude</title>
2210 By default, the altimeter will fire the main deployment charge at an
2211 elevation of 250 meters (about 820 feet) above ground. We think this
2212 is a good elevation for most air-frames, but feel free to change this
2213 to suit. In particular, if you are flying two altimeters, you may
2215 deployment elevation for the backup altimeter to be something lower
2216 than the primary so that both pyrotechnic charges don't fire
2221 <title>Maximum Flight Log</title>
2223 Changing this value will set the maximum amount of flight
2224 log storage that an individual flight will use. The
2225 available storage is divided into as many flights of the
2226 specified size as can fit in the available space. You can
2227 download and erase individual flight logs. If you fill up
2228 the available storage, future flights will not get logged
2229 until you erase some of the stored ones.
2232 Even though our flight computers (except TeleMini v1.0) can store
2233 multiple flights, we strongly recommend downloading and saving
2234 flight data after each flight.
2238 <title>Ignite Mode</title>
2240 Instead of firing one charge at apogee and another charge at
2241 a fixed height above the ground, you can configure the
2242 altimeter to fire both at apogee or both during
2243 descent. This was added to support an airframe Bdale designed that
2244 had two altimeters, one in the fin can and one in the nose.
2247 Providing the ability to use both igniters for apogee or
2248 main allows some level of redundancy without needing two
2249 flight computers. In Redundant Apogee or Redundant Main
2250 mode, the two charges will be fired two seconds apart.
2254 <title>Pad Orientation</title>
2256 TeleMetrum and TeleMega measure acceleration along the axis
2257 of the board. Which way the board is oriented affects the
2258 sign of the acceleration value. Instead of trying to guess
2259 which way the board is mounted in the air frame, the
2260 altimeter must be explicitly configured for either Antenna
2261 Up or Antenna Down. The default, Antenna Up, expects the end
2262 of the board connected to the 70cm antenna to be nearest the
2263 nose of the rocket, with the end containing the screw
2264 terminals nearest the tail.
2268 <title>Configurable Pyro Channels</title>
2270 In addition to the usual Apogee and Main pyro channels,
2271 TeleMega has four additional channels that can be configured
2272 to activate when various flight conditions are
2273 satisfied. You can select as many conditions as necessary;
2274 all of them must be met in order to activate the
2275 channel. The conditions available are:
2280 Acceleration away from the ground. Select a value, and
2281 then choose whether acceleration should be above or
2282 below that value. Acceleration is positive upwards, so
2283 accelerating towards the ground would produce negative
2284 numbers. Acceleration during descent is noisy and
2285 inaccurate, so be careful when using it during these
2286 phases of the flight.
2291 Vertical speed. Select a value, and then choose whether
2292 vertical speed should be above or below that
2293 value. Speed is positive upwards, so moving towards the
2294 ground would produce negative numbers. Speed during
2295 descent is a bit noisy and so be careful when using it
2296 during these phases of the flight.
2301 Height. Select a value, and then choose whether the
2302 height above the launch pad should be above or below
2308 Orientation. TeleMega contains a 3-axis gyroscope and
2309 accelerometer which is used to measure the current
2310 angle. Note that this angle is not the change in angle
2311 from the launch pad, but rather absolute relative to
2312 gravity; the 3-axis accelerometer is used to compute the
2313 angle of the rocket on the launch pad and initialize the
2314 system. Because this value is computed by integrating
2315 rate gyros, it gets progressively less accurate as the
2316 flight goes on. It should have an accumulated error of
2317 less than 0.2°/second (after 10 seconds of flight, the
2318 error should be less than 2°).
2321 The usual use of the orientation configuration is to
2322 ensure that the rocket is traveling mostly upwards when
2323 deciding whether to ignite air starts or additional
2324 stages. For that, choose a reasonable maximum angle
2325 (like 20°) and set the motor igniter to require an angle
2326 of less than that value.
2331 Flight Time. Time since boost was detected. Select a
2332 value and choose whether to activate the pyro channel
2333 before or after that amount of time.
2338 Ascending. A simple test saying whether the rocket is
2339 going up or not. This is exactly equivalent to testing
2340 whether the speed is > 0.
2345 Descending. A simple test saying whether the rocket is
2346 going down or not. This is exactly equivalent to testing
2347 whether the speed is < 0.
2352 After Motor. The flight software counts each time the
2353 rocket starts accelerating (presumably due to a motor or
2354 motors igniting). Use this value to count ignitions for
2355 multi-staged or multi-airstart launches.
2360 Delay. This value doesn't perform any checks, instead it
2361 inserts a delay between the time when the other
2362 parameters become true and when the pyro channel is
2368 Flight State. The flight software tracks the flight
2369 through a sequence of states:
2373 Boost. The motor has lit and the rocket is
2374 accelerating upwards.
2379 Fast. The motor has burned out and the rocket is
2380 decelerating, but it is going faster than 200m/s.
2385 Coast. The rocket is still moving upwards and
2386 decelerating, but the speed is less than 200m/s.
2391 Drogue. The rocket has reached apogee and is heading
2392 back down, but is above the configured Main
2398 Main. The rocket is still descending, and is below
2404 Landed. The rocket is no longer moving.
2410 You can select a state to limit when the pyro channel
2411 may activate; note that the check is based on when the
2412 rocket transitions <emphasis>into</emphasis> the state, and so checking for
2413 “greater than Boost” means that the rocket is currently
2414 in boost or some later state.
2417 When a motor burns out, the rocket enters either Fast or
2418 Coast state (depending on how fast it is moving). If the
2419 computer detects upwards acceleration again, it will
2420 move back to Boost state.
2429 <title>AltosUI</title>
2433 <imagedata fileref="altosui.png" width="4.6in"/>
2438 The AltosUI program provides a graphical user interface for
2439 interacting with the Altus Metrum product family. AltosUI can
2440 monitor telemetry data, configure devices and many other
2441 tasks. The primary interface window provides a selection of
2442 buttons, one for each major activity in the system. This chapter
2443 is split into sections, each of which documents one of the tasks
2444 provided from the top-level toolbar.
2447 <title>Monitor Flight</title>
2448 <subtitle>Receive, Record and Display Telemetry Data</subtitle>
2450 Selecting this item brings up a dialog box listing all of the
2451 connected TeleDongle devices. When you choose one of these,
2452 AltosUI will create a window to display telemetry data as
2453 received by the selected TeleDongle device.
2458 <imagedata fileref="device-selection.png" width="3.1in"/>
2463 All telemetry data received are automatically recorded in
2464 suitable log files. The name of the files includes the current
2465 date and rocket serial and flight numbers.
2468 The radio frequency being monitored by the TeleDongle device is
2469 displayed at the top of the window. You can configure the
2470 frequency by clicking on the frequency box and selecting the desired
2471 frequency. AltosUI remembers the last frequency selected for each
2472 TeleDongle and selects that automatically the next time you use
2476 Below the TeleDongle frequency selector, the window contains a few
2477 significant pieces of information about the altimeter providing
2478 the telemetry data stream:
2482 <para>The configured call-sign</para>
2485 <para>The device serial number</para>
2488 <para>The flight number. Each altimeter remembers how many
2494 The rocket flight state. Each flight passes through several
2495 states including Pad, Boost, Fast, Coast, Drogue, Main and
2501 The Received Signal Strength Indicator value. This lets
2502 you know how strong a signal TeleDongle is receiving. The
2503 radio inside TeleDongle operates down to about -99dBm;
2504 weaker signals may not be receivable. The packet link uses
2505 error detection and correction techniques which prevent
2506 incorrect data from being reported.
2511 The age of the displayed data, in seconds since the last
2512 successfully received telemetry packet. In normal operation
2513 this will stay in the low single digits. If the number starts
2514 counting up, then you are no longer receiving data over the radio
2515 link from the flight computer.
2520 Finally, the largest portion of the window contains a set of
2521 tabs, each of which contain some information about the rocket.
2522 They're arranged in 'flight order' so that as the flight
2523 progresses, the selected tab automatically switches to display
2524 data relevant to the current state of the flight. You can select
2525 other tabs at any time. The final 'table' tab displays all of
2526 the raw telemetry values in one place in a spreadsheet-like format.
2529 <title>Launch Pad</title>
2533 <imagedata fileref="launch-pad.png" width="5.5in"/>
2538 The 'Launch Pad' tab shows information used to decide when the
2539 rocket is ready for flight. The first elements include red/green
2540 indicators, if any of these is red, you'll want to evaluate
2541 whether the rocket is ready to launch:
2544 <term>Battery Voltage</term>
2547 This indicates whether the Li-Po battery powering the
2548 flight computer has sufficient charge to last for
2549 the duration of the flight. A value of more than
2550 3.8V is required for a 'GO' status.
2555 <term>Apogee Igniter Voltage</term>
2558 This indicates whether the apogee
2559 igniter has continuity. If the igniter has a low
2560 resistance, then the voltage measured here will be close
2561 to the Li-Po battery voltage. A value greater than 3.2V is
2562 required for a 'GO' status.
2567 <term>Main Igniter Voltage</term>
2570 This indicates whether the main
2571 igniter has continuity. If the igniter has a low
2572 resistance, then the voltage measured here will be close
2573 to the Li-Po battery voltage. A value greater than 3.2V is
2574 required for a 'GO' status.
2579 <term>On-board Data Logging</term>
2582 This indicates whether there is
2583 space remaining on-board to store flight data for the
2584 upcoming flight. If you've downloaded data, but failed
2585 to erase flights, there may not be any space
2586 left. Most of our flight computers can store multiple
2587 flights, depending on the configured maximum flight log
2588 size. TeleMini v1.0 stores only a single flight, so it
2590 downloaded and erased after each flight to capture
2591 data. This only affects on-board flight logging; the
2592 altimeter will still transmit telemetry and fire
2593 ejection charges at the proper times even if the flight
2594 data storage is full.
2599 <term>GPS Locked</term>
2602 For a TeleMetrum or TeleMega device, this indicates whether the GPS receiver is
2603 currently able to compute position information. GPS requires
2604 at least 4 satellites to compute an accurate position.
2609 <term>GPS Ready</term>
2612 For a TeleMetrum or TeleMega device, this indicates whether GPS has reported at least
2613 10 consecutive positions without losing lock. This ensures
2614 that the GPS receiver has reliable reception from the
2622 The Launchpad tab also shows the computed launch pad position
2623 and altitude, averaging many reported positions to improve the
2624 accuracy of the fix.
2628 <title>Ascent</title>
2632 <imagedata fileref="ascent.png" width="5.5in"/>
2637 This tab is shown during Boost, Fast and Coast
2638 phases. The information displayed here helps monitor the
2639 rocket as it heads towards apogee.
2642 The height, speed, acceleration and tilt are shown along
2643 with the maximum values for each of them. This allows you to
2644 quickly answer the most commonly asked questions you'll hear
2648 The current latitude and longitude reported by the GPS are
2649 also shown. Note that under high acceleration, these values
2650 may not get updated as the GPS receiver loses position
2651 fix. Once the rocket starts coasting, the receiver should
2652 start reporting position again.
2655 Finally, the current igniter voltages are reported as in the
2656 Launch Pad tab. This can help diagnose deployment failures
2657 caused by wiring which comes loose under high acceleration.
2661 <title>Descent</title>
2665 <imagedata fileref="descent.png" width="5.5in"/>
2670 Once the rocket has reached apogee and (we hope) activated the
2671 apogee charge, attention switches to tracking the rocket on
2672 the way back to the ground, and for dual-deploy flights,
2673 waiting for the main charge to fire.
2676 To monitor whether the apogee charge operated correctly, the
2677 current descent rate is reported along with the current
2678 height. Good descent rates vary based on the choice of recovery
2679 components, but generally range from 15-30m/s on drogue and should
2680 be below 10m/s when under the main parachute in a dual-deploy flight.
2683 With GPS-equipped flight computers, you can locate the rocket in the
2684 sky using the elevation and bearing information to figure
2685 out where to look. Elevation is in degrees above the
2686 horizon. Bearing is reported in degrees relative to true
2687 north. Range can help figure out how big the rocket will
2688 appear. Ground Distance shows how far it is to a point
2689 directly under the rocket and can help figure out where the
2690 rocket is likely to land. Note that all of these values are
2691 relative to the pad location. If the elevation is near 90°,
2692 the rocket is over the pad, not over you.
2695 Finally, the igniter voltages are reported in this tab as
2696 well, both to monitor the main charge as well as to see what
2697 the status of the apogee charge is. Note that some commercial
2698 e-matches are designed to retain continuity even after being
2699 fired, and will continue to show as green or return from red to
2704 <title>Landed</title>
2708 <imagedata fileref="landed.png" width="5.5in"/>
2713 Once the rocket is on the ground, attention switches to
2714 recovery. While the radio signal is often lost once the
2715 rocket is on the ground, the last reported GPS position is
2716 generally within a short distance of the actual landing location.
2719 The last reported GPS position is reported both by
2720 latitude and longitude as well as a bearing and distance from
2721 the launch pad. The distance should give you a good idea of
2722 whether to walk or hitch a ride. Take the reported
2723 latitude and longitude and enter them into your hand-held GPS
2724 unit and have that compute a track to the landing location.
2727 Our flight computers will continue to transmit RDF
2728 tones after landing, allowing you to locate the rocket by
2729 following the radio signal if necessary. You may need to get
2730 away from the clutter of the flight line, or even get up on
2731 a hill (or your neighbor's RV roof) to receive the RDF signal.
2734 The maximum height, speed and acceleration reported
2735 during the flight are displayed for your admiring observers.
2736 The accuracy of these immediate values depends on the quality
2737 of your radio link and how many packets were received.
2738 Recovering the on-board data after flight may yield
2739 more precise results.
2742 To get more detailed information about the flight, you can
2743 click on the 'Graph Flight' button which will bring up a
2744 graph window for the current flight.
2748 <title>Table</title>
2752 <imagedata fileref="table.png" width="5.5in"/>
2757 The table view shows all of the data available from the
2758 flight computer. Probably the most useful data on
2759 this tab is the detailed GPS information, which includes
2760 horizontal dilution of precision information, and
2761 information about the signal being received from the satellites.
2765 <title>Site Map</title>
2769 <imagedata fileref="site-map.png" width="5.5in"/>
2774 When the TeleMetrum has a GPS fix, the Site Map tab will map
2775 the rocket's position to make it easier for you to locate the
2776 rocket, both while it is in the air, and when it has landed. The
2777 rocket's state is indicated by color: white for pad, red for
2778 boost, pink for fast, yellow for coast, light blue for drogue,
2779 dark blue for main, and black for landed.
2782 The map's default scale is approximately 3m (10ft) per pixel. The map
2783 can be dragged using the left mouse button. The map will attempt
2784 to keep the rocket roughly centered while data is being received.
2787 You can adjust the style of map and the zoom level with
2788 buttons on the right side of the map window. You can draw a
2789 line on the map by moving the mouse over the map with a
2790 button other than the left one pressed, or by pressing the
2791 left button while also holding down the shift key. The
2792 length of the line in real-world units will be shown at the
2796 Images are fetched automatically via the Google Maps Static API,
2797 and cached on disk for reuse. If map images cannot be downloaded,
2798 the rocket's path will be traced on a dark gray background
2802 You can pre-load images for your favorite launch sites
2803 before you leave home; check out the 'Preload Maps' section below.
2807 <title>Ignitor</title>
2811 <imagedata fileref="ignitor.png" width="5.5in"/>
2816 TeleMega includes four additional programmable pyro
2817 channels. The Ignitor tab shows whether each of them has
2818 continuity. If an ignitor has a low resistance, then the
2819 voltage measured here will be close to the pyro battery
2820 voltage. A value greater than 3.2V is required for a 'GO'
2826 <title>Save Flight Data</title>
2828 The altimeter records flight data to its internal flash memory.
2829 TeleMetrum data is recorded at a much higher rate than the telemetry
2830 system can handle, and is not subject to radio drop-outs. As
2831 such, it provides a more complete and precise record of the
2832 flight. The 'Save Flight Data' button allows you to read the
2833 flash memory and write it to disk.
2836 Clicking on the 'Save Flight Data' button brings up a list of
2837 connected flight computers and TeleDongle devices. If you select a
2838 flight computer, the flight data will be downloaded from that
2839 device directly. If you select a TeleDongle device, flight data
2840 will be downloaded from a flight computer over radio link via the
2841 specified TeleDongle. See the chapter on Controlling An Altimeter
2842 Over The Radio Link for more information.
2845 After the device has been selected, a dialog showing the
2846 flight data saved in the device will be shown allowing you to
2847 select which flights to download and which to delete. With
2848 version 0.9 or newer firmware, you must erase flights in order
2849 for the space they consume to be reused by another
2850 flight. This prevents accidentally losing flight data
2851 if you neglect to download data before flying again. Note that
2852 if there is no more space available in the device, then no
2853 data will be recorded during the next flight.
2856 The file name for each flight log is computed automatically
2857 from the recorded flight date, altimeter serial number and
2858 flight number information.
2862 <title>Replay Flight</title>
2864 Select this button and you are prompted to select a flight
2865 record file, either a .telem file recording telemetry data or a
2866 .eeprom file containing flight data saved from the altimeter
2870 Once a flight record is selected, the flight monitor interface
2871 is displayed and the flight is re-enacted in real time. Check
2872 the Monitor Flight chapter above to learn how this window operates.
2876 <title>Graph Data</title>
2878 Select this button and you are prompted to select a flight
2879 record file, either a .telem file recording telemetry data or a
2880 .eeprom file containing flight data saved from
2884 Note that telemetry files will generally produce poor graphs
2885 due to the lower sampling rate and missed telemetry packets.
2886 Use saved flight data in .eeprom files for graphing where possible.
2889 Once a flight record is selected, a window with multiple tabs is
2893 <title>Flight Graph</title>
2897 <imagedata fileref="graph.png" width="6in" scalefit="1"/>
2902 By default, the graph contains acceleration (blue),
2903 velocity (green) and altitude (red).
2906 The graph can be zoomed into a particular area by clicking and
2907 dragging down and to the right. Once zoomed, the graph can be
2908 reset by clicking and dragging up and to the left. Holding down
2909 control and clicking and dragging allows the graph to be panned.
2910 The right mouse button causes a pop-up menu to be displayed, giving
2911 you the option save or print the plot.
2915 <title>Configure Graph</title>
2919 <imagedata fileref="graph-configure.png" width="6in" scalefit="1"/>
2924 This selects which graph elements to show, and, at the
2925 very bottom, lets you switch between metric and
2930 <title>Flight Statistics</title>
2934 <imagedata fileref="graph-stats.png" width="6in" scalefit="1"/>
2939 Shows overall data computed from the flight.
2947 <imagedata fileref="graph-map.png" width="6in" scalefit="1"/>
2952 Shows a satellite image of the flight area overlaid
2953 with the path of the flight. The red concentric
2954 circles mark the launch pad, the black concentric
2955 circles mark the landing location.
2960 <title>Export Data</title>
2962 This tool takes the raw data files and makes them available for
2963 external analysis. When you select this button, you are prompted to
2964 select a flight data file, which can be either a .eeprom or .telem.
2965 The .eeprom files contain higher resolution and more continuous data,
2966 while .telem files contain receiver signal strength information.
2967 Next, a second dialog appears which is used to select
2968 where to write the resulting file. It has a selector to choose
2969 between CSV and KML file formats.
2972 <title>Comma Separated Value Format</title>
2974 This is a text file containing the data in a form suitable for
2975 import into a spreadsheet or other external data analysis
2976 tool. The first few lines of the file contain the version and
2977 configuration information from the altimeter, then
2978 there is a single header line which labels all of the
2979 fields. All of these lines start with a '#' character which
2980 many tools can be configured to skip over.
2983 The remaining lines of the file contain the data, with each
2984 field separated by a comma and at least one space. All of
2985 the sensor values are converted to standard units, with the
2986 barometric data reported in both pressure, altitude and
2987 height above pad units.
2991 <title>Keyhole Markup Language (for Google Earth)</title>
2993 This is the format used by Google Earth to provide an overlay
2994 within that application. With this, you can use Google Earth to
2995 see the whole flight path in 3D.
3000 <title>Configure Altimeter</title>
3004 <imagedata fileref="configure-altimeter.png" width="3.6in" scalefit="1"/>
3009 Select this button and then select either an altimeter or
3010 TeleDongle Device from the list provided. Selecting a TeleDongle
3011 device will use the radio link to configure a remote altimeter.
3014 The first few lines of the dialog provide information about the
3015 connected device, including the product name,
3016 software version and hardware serial number. Below that are the
3017 individual configuration entries.
3020 At the bottom of the dialog, there are four buttons:
3027 This writes any changes to the
3028 configuration parameter block in flash memory. If you don't
3029 press this button, any changes you make will be lost.
3037 This resets the dialog to the most recently saved values,
3038 erasing any changes you have made.
3046 This reboots the device. Use this to
3047 switch from idle to pad mode by rebooting once the rocket is
3048 oriented for flight, or to confirm changes you think you saved
3057 This closes the dialog. Any unsaved changes will be
3064 The rest of the dialog contains the parameters to be configured.
3067 <title>Main Deploy Altitude</title>
3069 This sets the altitude (above the recorded pad altitude) at
3070 which the 'main' igniter will fire. The drop-down menu shows
3071 some common values, but you can edit the text directly and
3072 choose whatever you like. If the apogee charge fires below
3073 this altitude, then the main charge will fire two seconds
3074 after the apogee charge fires.
3078 <title>Apogee Delay</title>
3080 When flying redundant electronics, it's often important to
3081 ensure that multiple apogee charges don't fire at precisely
3082 the same time, as that can over pressurize the apogee deployment
3083 bay and cause a structural failure of the air-frame. The Apogee
3084 Delay parameter tells the flight computer to fire the apogee
3085 charge a certain number of seconds after apogee has been
3090 <title>Apogee Lockoug</title>
3092 Apogee lockout is the number of seconds after boost where
3093 the flight computer will not fire the apogee charge, even if
3094 the rocket appears to be at apogee. This is often called
3095 'Mach Delay', as it is intended to prevent a flight computer
3096 from unintentionally firing apogee charges due to the pressure
3097 spike that occurrs across a mach transition. Altus Metrum
3098 flight computers include a Kalman filter which is not fooled
3099 by this sharp pressure increase, and so this setting should
3100 be left at the default value of zero to disable it.
3104 <title>Frequency</title>
3106 This configures which of the frequencies to use for both
3107 telemetry and packet command mode. Note that if you set this
3108 value via packet command mode, the TeleDongle frequency will
3109 also be automatically reconfigured to match so that
3110 communication will continue afterwards.
3114 <title>RF Calibration</title>
3116 The radios in every Altus Metrum device are calibrated at the
3117 factory to ensure that they transmit and receive on the
3118 specified frequency. If you need to you can adjust the calibration
3119 by changing this value. Do not do this without understanding what
3120 the value means, read the appendix on calibration and/or the source
3121 code for more information. To change a TeleDongle's calibration,
3122 you must reprogram the unit completely.
3126 <title>Telemetry/RDF/APRS Enable</title>
3128 Enables the radio for transmission during flight. When
3129 disabled, the radio will not transmit anything during flight
3134 <title>APRS Interval</title>
3136 How often to transmit GPS information via APRS (in
3137 seconds). When set to zero, APRS transmission is
3138 disabled. This option is available on TeleMetrum v2 and
3139 TeleMega boards. TeleMetrum v1 boards cannot transmit APRS
3140 packets. Note that a single APRS packet takes nearly a full
3141 second to transmit, so enabling this option will prevent
3142 sending any other telemetry during that time.
3146 <title>Callsign</title>
3148 This sets the call sign included in each telemetry packet. Set this
3149 as needed to conform to your local radio regulations.
3153 <title>Maximum Flight Log Size</title>
3155 This sets the space (in kilobytes) allocated for each flight
3156 log. The available space will be divided into chunks of this
3157 size. A smaller value will allow more flights to be stored,
3158 a larger value will record data from longer flights.
3162 <title>Ignitor Firing Mode</title>
3164 This configuration parameter allows the two standard ignitor
3165 channels (Apogee and Main) to be used in different
3170 <term>Dual Deploy</term>
3173 This is the usual mode of operation; the
3174 'apogee' channel is fired at apogee and the 'main'
3175 channel at the height above ground specified by the
3176 'Main Deploy Altitude' during descent.
3181 <term>Redundant Apogee</term>
3184 This fires both channels at
3185 apogee, the 'apogee' channel first followed after a two second
3186 delay by the 'main' channel.
3191 <term>Redundant Main</term>
3194 This fires both channels at the
3195 height above ground specified by the Main Deploy
3196 Altitude setting during descent. The 'apogee'
3197 channel is fired first, followed after a two second
3198 delay by the 'main' channel.
3205 <title>Pad Orientation</title>
3207 Because they include accelerometers, TeleMetrum and
3208 TeleMega are sensitive to the orientation of the board. By
3209 default, they expect the antenna end to point forward. This
3210 parameter allows that default to be changed, permitting the
3211 board to be mounted with the antenna pointing aft instead.
3215 <term>Antenna Up</term>
3218 In this mode, the antenna end of the
3219 flight computer must point forward, in line with the
3220 expected flight path.
3225 <term>Antenna Down</term>
3228 In this mode, the antenna end of the
3229 flight computer must point aft, in line with the
3230 expected flight path.
3237 <title>Beeper Frequency</title>
3239 The beeper on all Altus Metrum flight computers works best
3240 at 4000Hz, however if you have more than one flight computer
3241 in a single airframe, having all of them sound at the same
3242 frequency can be confusing. This parameter lets you adjust
3243 the base beeper frequency value.
3247 <title>Configure Pyro Channels</title>
3251 <imagedata fileref="configure-pyro.png" width="6in" scalefit="1"/>
3256 This opens a separate window to configure the additional
3257 pyro channels available on TeleMega. One column is
3258 presented for each channel. Each row represents a single
3259 parameter, if enabled the parameter must meet the specified
3260 test for the pyro channel to be fired. See the Pyro Channels
3261 section in the System Operation chapter above for a
3262 description of these parameters.
3265 Select conditions and set the related value; the pyro
3266 channel will be activated when <emphasis>all</emphasis> of the
3267 conditions are met. Each pyro channel has a separate set of
3268 configuration values, so you can use different values for
3269 the same condition with different channels.
3272 At the bottom of the window, the 'Pyro Firing Time'
3273 configuration sets the length of time (in seconds) which
3274 each of these pyro channels will fire for.
3277 Once you have selected the appropriate configuration for all
3278 of the necessary pyro channels, you can save the pyro
3279 configuration along with the rest of the flight computer
3280 configuration by pressing the 'Save' button in the main
3281 Configure Flight Computer window.
3286 <title>Configure AltosUI</title>
3290 <imagedata fileref="configure-altosui.png" width="2.4in" scalefit="1"/>
3295 This button presents a dialog so that you can configure the AltosUI global settings.
3298 <title>Voice Settings</title>
3300 AltosUI provides voice announcements during flight so that you
3301 can keep your eyes on the sky and still get information about
3302 the current flight status. However, sometimes you don't want
3309 <para>Turns all voice announcements on and off</para>
3313 <term>Test Voice</term>
3316 Plays a short message allowing you to verify
3317 that the audio system is working and the volume settings
3325 <title>Log Directory</title>
3327 AltosUI logs all telemetry data and saves all TeleMetrum flash
3328 data to this directory. This directory is also used as the
3329 staring point when selecting data files for display or export.
3332 Click on the directory name to bring up a directory choosing
3333 dialog, select a new directory and click 'Select Directory' to
3334 change where AltosUI reads and writes data files.
3338 <title>Callsign</title>
3340 This value is transmitted in each command packet sent from
3341 TeleDongle and received from an altimeter. It is not used in
3342 telemetry mode, as the callsign configured in the altimeter board
3343 is included in all telemetry packets. Configure this
3344 with the AltosUI operators call sign as needed to comply with
3345 your local radio regulations.
3348 Note that to successfully command a flight computer over the radio
3349 (to configure the altimeter, monitor idle, or fire pyro charges),
3350 the callsign configured here must exactly match the callsign
3351 configured in the flight computer. This matching is case
3356 <title>Imperial Units</title>
3358 This switches between metric units (meters) and imperial
3359 units (feet and miles). This affects the display of values
3360 use during flight monitoring, configuration, data graphing
3361 and all of the voice announcements. It does not change the
3362 units used when exporting to CSV files, those are always
3363 produced in metric units.
3367 <title>Font Size</title>
3369 Selects the set of fonts used in the flight monitor
3370 window. Choose between the small, medium and large sets.
3374 <title>Serial Debug</title>
3376 This causes all communication with a connected device to be
3377 dumped to the console from which AltosUI was started. If
3378 you've started it from an icon or menu entry, the output
3379 will simply be discarded. This mode can be useful to debug
3380 various serial communication issues.
3384 <title>Manage Frequencies</title>
3386 This brings up a dialog where you can configure the set of
3387 frequencies shown in the various frequency menus. You can
3388 add as many as you like, or even reconfigure the default
3389 set. Changing this list does not affect the frequency
3390 settings of any devices, it only changes the set of
3391 frequencies shown in the menus.
3396 <title>Configure Groundstation</title>
3400 <imagedata fileref="configure-groundstation.png" width="3.1in" scalefit="1"/>
3405 Select this button and then select a TeleDongle Device from the list provided.
3408 The first few lines of the dialog provide information about the
3409 connected device, including the product name,
3410 software version and hardware serial number. Below that are the
3411 individual configuration entries.
3414 Note that the TeleDongle itself doesn't save any configuration
3415 data, the settings here are recorded on the local machine in
3416 the Java preferences database. Moving the TeleDongle to
3417 another machine, or using a different user account on the same
3418 machine will cause settings made here to have no effect.
3421 At the bottom of the dialog, there are three buttons:
3428 This writes any changes to the
3429 local Java preferences file. If you don't
3430 press this button, any changes you make will be lost.
3438 This resets the dialog to the most recently saved values,
3439 erasing any changes you have made.
3447 This closes the dialog. Any unsaved changes will be
3454 The rest of the dialog contains the parameters to be configured.
3457 <title>Frequency</title>
3459 This configures the frequency to use for both telemetry and
3460 packet command mode. Set this before starting any operation
3461 involving packet command mode so that it will use the right
3462 frequency. Telemetry monitoring mode also provides a menu to
3463 change the frequency, and that menu also sets the same Java
3464 preference value used here.
3468 <title>Radio Calibration</title>
3470 The radios in every Altus Metrum device are calibrated at the
3471 factory to ensure that they transmit and receive on the
3472 specified frequency. To change a TeleDongle's calibration,
3473 you must reprogram the unit completely, so this entry simply
3474 shows the current value and doesn't allow any changes.
3479 <title>Flash Image</title>
3481 This reprograms Altus Metrum devices with new
3482 firmware. TeleMetrum v1.x, TeleDongle, TeleMini and TeleBT are
3483 all reprogrammed by using another similar unit as a
3484 programming dongle (pair programming). TeleMega, TeleMetrum v2
3485 and EasyMini are all programmed directly over their USB ports
3486 (self programming). Please read the directions for flashing
3487 devices in the Updating Device Firmware chapter below.
3491 <title>Fire Igniter</title>
3495 <imagedata fileref="fire-igniter.png" width="1.2in" scalefit="1"/>
3500 This activates the igniter circuits in the flight computer to help
3501 test recovery systems deployment. Because this command can operate
3502 over the Packet Command Link, you can prepare the rocket as
3503 for flight and then test the recovery system without needing
3504 to snake wires inside the air-frame.
3507 Selecting the 'Fire Igniter' button brings up the usual device
3508 selection dialog. Pick the desired device. This brings up another
3509 window which shows the current continuity test status for all
3510 of the pyro channels.
3513 Next, select the desired igniter to fire. This will enable the
3517 Select the 'Arm' button. This enables the 'Fire' button. The
3518 word 'Arm' is replaced by a countdown timer indicating that
3519 you have 10 seconds to press the 'Fire' button or the system
3520 will deactivate, at which point you start over again at
3521 selecting the desired igniter.
3525 <title>Scan Channels</title>
3529 <imagedata fileref="scan-channels.png" width="3.2in" scalefit="1"/>
3534 This listens for telemetry packets on all of the configured
3535 frequencies, displaying information about each device it
3536 receives a packet from. You can select which of the three
3537 telemetry formats should be tried; by default, it only listens
3538 for the standard telemetry packets used in v1.0 and later
3543 <title>Load Maps</title>
3547 <imagedata fileref="load-maps.png" width="5.2in" scalefit="1"/>
3552 Before heading out to a new launch site, you can use this to
3553 load satellite images in case you don't have internet
3554 connectivity at the site. This loads a fairly large area
3555 around the launch site, which should cover any flight you're likely to make.
3558 There's a drop-down menu of launch sites we know about; if
3559 your favorites aren't there, please let us know the lat/lon
3560 and name of the site. The contents of this list are actually
3561 downloaded from our server at run-time, so as new sites are sent
3562 in, they'll get automatically added to this list.
3563 If the launch site isn't in the list, you can manually enter the lat/lon values
3566 There are four different kinds of maps you can view; you can
3567 select which to download by selecting as many as you like from
3568 the available types:
3574 A combination of satellite imagery and road data. This
3575 is the default view.
3580 <term>Satellite</term>
3583 Just the satellite imagery without any annotation.
3588 <term>Roadmap</term>
3591 Roads, political boundaries and a few geographic features.
3596 <term>Terrain</term>
3599 Contour intervals and shading that show hills and
3607 You can specify the range of zoom levels to download; smaller
3608 numbers show more area with less resolution. The default
3609 level, 0, shows about 3m/pixel. One zoom level change
3610 doubles or halves that number.
3613 The Tile Radius value sets how large an area around the center
3614 point to download. Each tile is 512x512 pixels, and the
3615 'radius' value specifies how many tiles away from the center
3616 will be downloaded. Specify a radius of 0 and you get only the
3617 center tile. A radius of 1 loads a 3x3 grid, centered on the
3621 Clicking the 'Load Map' button will fetch images from Google
3622 Maps; note that Google limits how many images you can fetch at
3623 once, so if you load more than one launch site, you may get
3624 some gray areas in the map which indicate that Google is tired
3625 of sending data to you. Try again later.
3629 <title>Monitor Idle</title>
3631 This brings up a dialog similar to the Monitor Flight UI,
3632 except it works with the altimeter in “idle” mode by sending
3633 query commands to discover the current state rather than
3634 listening for telemetry packets. Because this uses command
3635 mode, it needs to have the TeleDongle and flight computer
3636 callsigns match exactly. If you can receive telemetry, but
3637 cannot manage to run Monitor Idle, then it's very likely that
3638 your callsigns are different in some way.
3643 <title>AltosDroid</title>
3645 AltosDroid provides the same flight monitoring capabilities as
3646 AltosUI, but runs on Android devices and is designed to connect
3647 to a TeleBT receiver over Bluetooth™. AltosDroid monitors
3648 telemetry data, logging it to internal storage in the Android
3649 device, and presents that data in a UI the same way the 'Monitor
3650 Flight' window does in AltosUI.
3653 This manual will explain how to configure AltosDroid, connect
3654 to TeleBT, operate the flight monitoring interface and describe
3655 what the displayed data means.
3658 <title>Installing AltosDroid</title>
3660 AltosDroid is available from the Google Play store. To install
3661 it on your Android device, open the Google Play Store
3662 application and search for “altosdroid”. Make sure you don't
3663 have a space between “altos” and “droid” or you probably won't
3664 find what you want. That should bring you to the right page
3665 from which you can download and install the application.
3669 <title>Connecting to TeleBT</title>
3671 Press the Android 'Menu' button or soft-key to see the
3672 configuration options available. Select the 'Connect a device'
3673 option and then the 'Scan for devices' entry at the bottom to
3674 look for your TeleBT device. Select your device, and when it
3675 asks for the code, enter '1234'.
3678 Subsequent connections will not require you to enter that
3679 code, and your 'paired' device will appear in the list without
3684 <title>Configuring AltosDroid</title>
3686 The only configuration option available for AltosDroid is
3687 which frequency to listen on. Press the Android 'Menu' button
3688 or soft-key and pick the 'Select radio frequency' entry. That
3689 brings up a menu of pre-set radio frequencies; pick the one
3690 which matches your altimeter.
3694 <title>AltosDroid Flight Monitoring</title>
3696 AltosDroid is designed to mimic the AltosUI flight monitoring
3697 display, providing separate tabs for each stage of your rocket
3698 flight along with a tab containing a map of the local area
3699 with icons marking the current location of the altimeter and
3705 The 'Launch Pad' tab shows information used to decide when the
3706 rocket is ready for flight. The first elements include red/green
3707 indicators, if any of these is red, you'll want to evaluate
3708 whether the rocket is ready to launch:
3711 <term>Battery Voltage</term>
3714 This indicates whether the Li-Po battery
3715 powering the TeleMetrum has sufficient charge to last for
3716 the duration of the flight. A value of more than
3717 3.8V is required for a 'GO' status.
3722 <term>Apogee Igniter Voltage</term>
3725 This indicates whether the apogee
3726 igniter has continuity. If the igniter has a low
3727 resistance, then the voltage measured here will be close
3728 to the Li-Po battery voltage. A value greater than 3.2V is
3729 required for a 'GO' status.
3734 <term>Main Igniter Voltage</term>
3737 This indicates whether the main
3738 igniter has continuity. If the igniter has a low
3739 resistance, then the voltage measured here will be close
3740 to the Li-Po battery voltage. A value greater than 3.2V is
3741 required for a 'GO' status.
3746 <term>On-board Data Logging</term>
3749 This indicates whether there is
3750 space remaining on-board to store flight data for the
3751 upcoming flight. If you've downloaded data, but failed
3752 to erase flights, there may not be any space
3753 left. TeleMetrum can store multiple flights, depending
3754 on the configured maximum flight log size. TeleMini
3755 stores only a single flight, so it will need to be
3756 downloaded and erased after each flight to capture
3757 data. This only affects on-board flight logging; the
3758 altimeter will still transmit telemetry and fire
3759 ejection charges at the proper times.
3764 <term>GPS Locked</term>
3767 For a TeleMetrum or TeleMega device, this indicates whether the GPS receiver is
3768 currently able to compute position information. GPS requires
3769 at least 4 satellites to compute an accurate position.
3774 <term>GPS Ready</term>
3777 For a TeleMetrum or TeleMega device, this indicates whether GPS has reported at least
3778 10 consecutive positions without losing lock. This ensures
3779 that the GPS receiver has reliable reception from the
3787 The Launchpad tab also shows the computed launch pad position
3788 and altitude, averaging many reported positions to improve the
3789 accuracy of the fix.
3794 <title>Downloading Flight Logs</title>
3796 AltosDroid always saves every bit of telemetry data it
3797 receives. To download that to a computer for use with AltosUI,
3798 simply remove the SD card from your Android device, or connect
3799 your device to your computer's USB port and browse the files
3800 on that device. You will find '.telem' files in the TeleMetrum
3801 directory that will work with AltosUI directly.
3806 <title>Using Altus Metrum Products</title>
3808 <title>Being Legal</title>
3810 First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
3811 other authorization to legally operate the radio transmitters that are part
3816 <title>In the Rocket</title>
3818 In the rocket itself, you just need a flight computer and
3819 a single-cell, 3.7 volt nominal Li-Po rechargeable battery. An
3820 850mAh battery weighs less than a 9V alkaline battery, and will
3821 run a TeleMetrum or TeleMega for hours.
3822 A 110mAh battery weighs less than a triple A battery and is a good
3823 choice for use with TeleMini.
3826 By default, we ship flight computers with a simple wire antenna.
3827 If your electronics bay or the air-frame it resides within is made
3828 of carbon fiber, which is opaque to RF signals, you may prefer to
3829 install an SMA connector so that you can run a coaxial cable to an
3830 antenna mounted elsewhere in the rocket. However, note that the
3831 GPS antenna is fixed on all current products, so you really want
3832 to install the flight computer in a bay made of RF-transparent
3833 materials if at all possible.
3837 <title>On the Ground</title>
3839 To receive the data stream from the rocket, you need an antenna and short
3840 feed-line connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> units. If possible, use an SMA to BNC
3841 adapter instead of feedline between the antenna feedpoint and
3842 TeleDongle, as this will give you the best performance. The
3843 TeleDongle in turn plugs directly into the USB port on a notebook
3844 computer. Because TeleDongle looks like a simple serial port, your computer
3845 does not require special device drivers... just plug it in.
3848 The GUI tool, AltosUI, is written in Java and runs across
3849 Linux, Mac OS and Windows. There's also a suite of C tools
3850 for Linux which can perform most of the same tasks.
3853 Alternatively, a TeleBT attached with an SMA to BNC adapter at the
3854 feed point of a hand-held yagi used in conjunction with an Android
3855 device running AltosDroid makes an outstanding ground station.
3858 After the flight, you can use the radio link to extract the more detailed data
3859 logged in either TeleMetrum or TeleMini devices, or you can use a mini USB cable to plug into the
3860 TeleMetrum board directly. Pulling out the data without having to open up
3861 the rocket is pretty cool! A USB cable is also how you charge the Li-Po
3862 battery, so you'll want one of those anyway... the same cable used by lots
3863 of digital cameras and other modern electronic stuff will work fine.
3866 If your rocket lands out of sight, you may enjoy having a hand-held
3867 GPS receiver, so that you can put in a way-point for the last
3868 reported rocket position before touch-down. This makes looking for
3869 your rocket a lot like Geo-Caching... just go to the way-point and
3870 look around starting from there. AltosDroid on an Android device
3871 with GPS receiver works great for this, too!
3874 You may also enjoy having a ham radio “HT” that covers the 70cm band... you
3875 can use that with your antenna to direction-find the rocket on the ground
3876 the same way you can use a Walston or Beeline tracker. This can be handy
3877 if the rocket is hiding in sage brush or a tree, or if the last GPS position
3878 doesn't get you close enough because the rocket dropped into a canyon, or
3879 the wind is blowing it across a dry lake bed, or something like that... Keith
3880 currently uses a Yaesu VX-7R, Bdale has a Baofung UV-5R
3881 which isn't as nice, but was a whole lot cheaper.
3884 So, to recap, on the ground the hardware you'll need includes:
3885 <orderedlist inheritnum='inherit' numeration='arabic'>
3888 an antenna and feed-line or adapter
3903 optionally, a hand-held GPS receiver
3908 optionally, an HT or receiver covering 435 MHz
3914 The best hand-held commercial directional antennas we've found for radio
3915 direction finding rockets are from
3916 <ulink url="http://www.arrowantennas.com/" >
3919 The 440-3 and 440-5 are both good choices for finding a
3920 TeleMetrum- or TeleMini- equipped rocket when used with a suitable
3921 70cm HT. TeleDongle and an SMA to BNC adapter fit perfectly
3922 between the driven element and reflector of Arrow antennas.
3926 <title>Data Analysis</title>
3928 Our software makes it easy to log the data from each flight, both the
3929 telemetry received during the flight itself, and the more
3930 complete data log recorded in the flash memory on the altimeter
3931 board. Once this data is on your computer, our post-flight tools make it
3932 easy to quickly get to the numbers everyone wants, like apogee altitude,
3933 max acceleration, and max velocity. You can also generate and view a
3934 standard set of plots showing the altitude, acceleration, and
3935 velocity of the rocket during flight. And you can even export a TeleMetrum data file
3936 usable with Google Maps and Google Earth for visualizing the flight path
3937 in two or three dimensions!
3940 Our ultimate goal is to emit a set of files for each flight that can be
3941 published as a web page per flight, or just viewed on your local disk with
3946 <title>Future Plans</title>
3948 We've designed a simple GPS based radio tracker called TeleGPS.
3949 If all goes well, we hope to introduce this in the first
3953 We have designed and prototyped several “companion boards” that
3954 can attach to the companion connector on TeleMetrum and TeleMega
3955 flight computers to collect more data, provide more pyro channels,
3956 and so forth. We do not yet know if or when any of these boards
3957 will be produced in enough quantity to sell. If you have specific
3958 interests for data collection or control of events in your rockets
3959 beyond the capabilities of our existing productions, please let
3963 Because all of our work is open, both the hardware designs and the
3964 software, if you have some great idea for an addition to the current
3965 Altus Metrum family, feel free to dive in and help! Or let us know
3966 what you'd like to see that we aren't already working on, and maybe
3967 we'll get excited about it too...
3971 <ulink url="http://altusmetrum.org/">web site</ulink> for more news
3972 and information as our family of products evolves!
3977 <title>Altimeter Installation Recommendations</title>
3979 Building high-power rockets that fly safely is hard enough. Mix
3980 in some sophisticated electronics and a bunch of radio energy
3981 and some creativity and/or compromise may be required. This chapter
3982 contains some suggestions about how to install Altus Metrum
3983 products into a rocket air-frame, including how to safely and
3984 reliably mix a variety of electronics into the same air-frame.
3987 <title>Mounting the Altimeter</title>
3989 The first consideration is to ensure that the altimeter is
3990 securely fastened to the air-frame. For most of our products, we
3991 prefer nylon standoffs and nylon screws; they're good to at least 50G
3992 and cannot cause any electrical issues on the board. Metal screws
3993 and standoffs are fine, too, just be careful to avoid electrical
3994 shorts! For TeleMini v1.0, we usually cut small pieces of 1/16 inch
3996 under the screw holes, and then take 2x56 nylon screws and
3997 screw them through the TeleMini mounting holes, through the
3998 balsa and into the underlying material.
4000 <orderedlist inheritnum='inherit' numeration='arabic'>
4003 Make sure accelerometer-equipped products like TeleMetrum and
4004 TeleMega are aligned precisely along the axis of
4005 acceleration so that the accelerometer can accurately
4006 capture data during the flight.
4011 Watch for any metal touching components on the
4012 board. Shorting out connections on the bottom of the board
4013 can cause the altimeter to fail during flight.
4019 <title>Dealing with the Antenna</title>
4021 The antenna supplied is just a piece of solid, insulated,
4022 wire. If it gets damaged or broken, it can be easily
4023 replaced. It should be kept straight and not cut; bending or
4024 cutting it will change the resonant frequency and/or
4025 impedance, making it a less efficient radiator and thus
4026 reducing the range of the telemetry signal.
4029 Keeping metal away from the antenna will provide better range
4030 and a more even radiation pattern. In most rockets, it's not
4031 entirely possible to isolate the antenna from metal
4032 components; there are often bolts, all-thread and wires from other
4033 electronics to contend with. Just be aware that the more stuff
4034 like this around the antenna, the lower the range.
4037 Make sure the antenna is not inside a tube made or covered
4038 with conducting material. Carbon fiber is the most common
4039 culprit here -- CF is a good conductor and will effectively
4040 shield the antenna, dramatically reducing signal strength and
4041 range. Metallic flake paint is another effective shielding
4042 material which should be avoided around any antennas.
4045 If the ebay is large enough, it can be convenient to simply
4046 mount the altimeter at one end and stretch the antenna out
4047 inside. Taping the antenna to the sled can keep it straight
4048 under acceleration. If there are metal rods, keep the
4049 antenna as far away as possible.
4052 For a shorter ebay, it's quite practical to have the antenna
4053 run through a bulkhead and into an adjacent bay. Drill a small
4054 hole in the bulkhead, pass the antenna wire through it and
4055 then seal it up with glue or clay. We've also used acrylic
4056 tubing to create a cavity for the antenna wire. This works a
4057 bit better in that the antenna is known to stay straight and
4058 not get folded by recovery components in the bay. Angle the
4059 tubing towards the side wall of the rocket and it ends up
4060 consuming very little space.
4063 If you need to place the UHF antenna at a distance from the
4064 altimeter, you can replace the antenna with an edge-mounted
4065 SMA connector, and then run 50Ω coax from the board to the
4066 antenna. Building a remote antenna is beyond the scope of this
4071 <title>Preserving GPS Reception</title>
4073 The GPS antenna and receiver used in TeleMetrum and TeleMega is
4074 highly sensitive and normally have no trouble tracking enough
4075 satellites to provide accurate position information for
4076 recovering the rocket. However, there are many ways the GPS signal
4077 can end up attenuated, negatively affecting GPS performance.
4078 <orderedlist inheritnum='inherit' numeration='arabic'>
4081 Conductive tubing or coatings. Carbon fiber and metal
4082 tubing, or metallic paint will all dramatically attenuate the
4083 GPS signal. We've never heard of anyone successfully
4084 receiving GPS from inside these materials.
4089 Metal components near the GPS patch antenna. These will
4090 de-tune the patch antenna, changing the resonant frequency
4091 away from the L1 carrier and reduce the effectiveness of the
4092 antenna. You can place as much stuff as you like beneath the
4093 antenna as that's covered with a ground plane. But, keep
4094 wires and metal out from above the patch antenna.
4101 <title>Radio Frequency Interference</title>
4103 Any altimeter will generate RFI; the digital circuits use
4104 high-frequency clocks that spray radio interference across a
4105 wide band. Altus Metrum altimeters generate intentional radio
4106 signals as well, increasing the amount of RF energy around the board.
4109 Rocketry altimeters also use precise sensors measuring air
4110 pressure and acceleration. Tiny changes in voltage can cause
4111 these sensor readings to vary by a huge amount. When the
4112 sensors start mis-reporting data, the altimeter can either
4113 fire the igniters at the wrong time, or not fire them at all.
4116 Voltages are induced when radio frequency energy is
4117 transmitted from one circuit to another. Here are things that
4118 influence the induced voltage and current:
4123 Keep wires from different circuits apart. Moving circuits
4124 further apart will reduce RFI.
4129 Avoid parallel wires from different circuits. The longer two
4130 wires run parallel to one another, the larger the amount of
4131 transferred energy. Cross wires at right angles to reduce
4137 Twist wires from the same circuits. Two wires the same
4138 distance from the transmitter will get the same amount of
4139 induced energy which will then cancel out. Any time you have
4140 a wire pair running together, twist the pair together to
4141 even out distances and reduce RFI. For altimeters, this
4142 includes battery leads, switch hookups and igniter
4148 Avoid resonant lengths. Know what frequencies are present
4149 in the environment and avoid having wire lengths near a
4150 natural resonant length. Altus Metrum products transmit on the
4151 70cm amateur band, so you should avoid lengths that are a
4152 simple ratio of that length; essentially any multiple of ¼
4153 of the wavelength (17.5cm).
4159 <title>The Barometric Sensor</title>
4161 Altusmetrum altimeters measure altitude with a barometric
4162 sensor, essentially measuring the amount of air above the
4163 rocket to figure out how high it is. A large number of
4164 measurements are taken as the altimeter initializes itself to
4165 figure out the pad altitude. Subsequent measurements are then
4166 used to compute the height above the pad.
4169 To accurately measure atmospheric pressure, the ebay
4170 containing the altimeter must be vented outside the
4171 air-frame. The vent must be placed in a region of linear
4172 airflow, have smooth edges, and away from areas of increasing or
4173 decreasing pressure.
4176 All barometric sensors are quite sensitive to chemical damage from
4177 the products of APCP or BP combustion, so make sure the ebay is
4178 carefully sealed from any compartment which contains ejection
4183 <title>Ground Testing</title>
4185 The most important aspect of any installation is careful
4186 ground testing. Bringing an air-frame up to the LCO table which
4187 hasn't been ground tested can lead to delays or ejection
4188 charges firing on the pad, or, even worse, a recovery system
4192 Do a 'full systems' test that includes wiring up all igniters
4193 without any BP and turning on all of the electronics in flight
4194 mode. This will catch any mistakes in wiring and any residual
4195 RFI issues that might accidentally fire igniters at the wrong
4196 time. Let the air-frame sit for several minutes, checking for
4197 adequate telemetry signal strength and GPS lock. If any igniters
4198 fire unexpectedly, find and resolve the issue before loading any
4202 Ground test the ejection charges. Prepare the rocket for
4203 flight, loading ejection charges and igniters. Completely
4204 assemble the air-frame and then use the 'Fire Igniters'
4205 interface through a TeleDongle to command each charge to
4206 fire. Make sure the charge is sufficient to robustly separate
4207 the air-frame and deploy the recovery system.
4212 <title>Updating Device Firmware</title>
4214 TeleMega, TeleMetrum v2 and EasyMini are all programmed directly
4215 over their USB connectors (self programming). TeleMetrum v1, TeleMini and
4216 TeleDongle are all programmed by using another device as a
4217 programmer (pair programming). It's important to recognize which
4218 kind of devices you have before trying to reprogram them.
4221 You may wish to begin by ensuring you have current firmware images.
4222 These are distributed as part of the AltOS software bundle that
4223 also includes the AltosUI ground station program. Newer ground
4224 station versions typically work fine with older firmware versions,
4225 so you don't need to update your devices just to try out new
4226 software features. You can always download the most recent
4227 version from <ulink url="http://www.altusmetrum.org/AltOS/"/>.
4230 If you need to update the firmware on a TeleDongle, we recommend
4231 updating the altimeter first, before updating TeleDongle. However,
4232 note that TeleDongle rarely need to be updated. Any firmware version
4233 1.0.1 or later will work, version 1.2.1 may have improved receiver
4234 performance slightly.
4237 Self-programmable devices (TeleMega, TeleMetrum v2 and EasyMini)
4238 are reprogrammed by connecting them to your computer over USB
4242 Updating TeleMega, TeleMetrum v2 or EasyMini Firmware
4244 <orderedlist inheritnum='inherit' numeration='arabic'>
4247 Attach a battery and power switch to the target
4248 device. Power up the device.
4253 Using a Micro USB cable, connect the target device to your
4254 computer's USB socket.
4259 Run AltosUI, and select 'Flash Image' from the File menu.
4264 Select the target device in the Device Selection dialog.
4269 Select the image you want to flash to the device, which
4270 should have a name in the form
4271 <product>-v<product-version>-<software-version>.ihx, such
4272 as TeleMega-v1.0-1.3.0.ihx.
4277 Make sure the configuration parameters are reasonable
4278 looking. If the serial number and/or RF configuration
4279 values aren't right, you'll need to change them.
4284 Hit the 'OK' button and the software should proceed to flash
4285 the device with new firmware, showing a progress bar.
4290 Verify that the device is working by using the 'Configure
4291 Altimeter' item to check over the configuration.
4296 <title>Recovering From Self-Flashing Failure</title>
4298 If the firmware loading fails, it can leave the device
4299 unable to boot. Not to worry, you can force the device to
4300 start the boot loader instead, which will let you try to
4301 flash the device again.
4304 On each device, connecting two pins from one of the exposed
4305 connectors will force the boot loader to start, even if the
4306 regular operating system has been corrupted in some way.
4310 <term>TeleMega</term>
4313 Connect pin 6 and pin 1 of the companion connector. Pin 1
4314 can be identified by the square pad around it, and then
4315 the pins could sequentially across the board. Be very
4316 careful to <emphasis>not</emphasis> short pin 8 to
4317 anything as that is connected directly to the battery. Pin
4318 7 carries 3.3V and the board will crash if that is
4319 connected to pin 1, but shouldn't damage the board.
4324 <term>TeleMetrum v2</term>
4327 Connect pin 6 and pin 1 of the companion connector. Pin 1
4328 can be identified by the square pad around it, and then
4329 the pins could sequentially across the board. Be very
4330 careful to <emphasis>not</emphasis> short pin 8 to
4331 anything as that is connected directly to the battery. Pin
4332 7 carries 3.3V and the board will crash if that is
4333 connected to pin 1, but shouldn't damage the board.
4338 <term>EasyMini</term>
4341 Connect pin 6 and pin 1 of the debug connector, which is
4342 the six holes next to the beeper. Pin 1 can be identified
4343 by the square pad around it, and then the pins could
4344 sequentially across the board, making Pin 6 the one on the
4345 other end of the row.
4351 Once you've located the right pins:
4353 <orderedlist inheritnum='inherit' numeration='arabic'>
4356 Turn the altimeter power off.
4366 Connect the indicated terminals together with a short
4367 piece of wire. Take care not to accidentally connect
4378 Turn the board power on.
4383 The board should now be visible over USB as 'AltosFlash'
4384 and be ready to receive firmware.
4389 Once the board has been powered up, you can remove the
4397 <title>Pair Programming</title>
4399 The big concept to understand is that you have to use a
4400 TeleMega, TeleMetrum or TeleDongle as a programmer to update a
4401 pair programmed device. Due to limited memory resources in the
4402 cc1111, we don't support programming directly over USB for these
4407 <title>Updating TeleMetrum v1.x Firmware</title>
4408 <orderedlist inheritnum='inherit' numeration='arabic'>
4411 Find the 'programming cable' that you got as part of the starter
4412 kit, that has a red 8-pin MicroMaTch connector on one end and a
4413 red 4-pin MicroMaTch connector on the other end.
4418 Take the 2 screws out of the TeleDongle case to get access
4419 to the circuit board.
4424 Plug the 8-pin end of the programming cable to the
4425 matching connector on the TeleDongle, and the 4-pin end to the
4426 matching connector on the TeleMetrum.
4427 Note that each MicroMaTch connector has an alignment pin that
4428 goes through a hole in the PC board when you have the cable
4434 Attach a battery to the TeleMetrum board.
4439 Plug the TeleDongle into your computer's USB port, and power
4445 Run AltosUI, and select 'Flash Image' from the File menu.
4450 Pick the TeleDongle device from the list, identifying it as the
4456 Select the image you want put on the TeleMetrum, which should have a
4457 name in the form telemetrum-v1.2-1.0.0.ihx. It should be visible
4458 in the default directory, if not you may have to poke around
4459 your system to find it.
4464 Make sure the configuration parameters are reasonable
4465 looking. If the serial number and/or RF configuration
4466 values aren't right, you'll need to change them.
4471 Hit the 'OK' button and the software should proceed to flash
4472 the TeleMetrum with new firmware, showing a progress bar.
4477 Confirm that the TeleMetrum board seems to have updated OK, which you
4478 can do by plugging in to it over USB and using a terminal program
4479 to connect to the board and issue the 'v' command to check
4485 If something goes wrong, give it another try.
4491 <title>Updating TeleMini Firmware</title>
4492 <orderedlist inheritnum='inherit' numeration='arabic'>
4495 You'll need a special 'programming cable' to reprogram the
4496 TeleMini. You can make your own using an 8-pin MicroMaTch
4497 connector on one end and a set of four pins on the other.
4502 Take the 2 screws out of the TeleDongle case to get access
4503 to the circuit board.
4508 Plug the 8-pin end of the programming cable to the matching
4509 connector on the TeleDongle, and the 4-pins into the holes
4510 in the TeleMini circuit board. Note that the MicroMaTch
4511 connector has an alignment pin that goes through a hole in
4512 the PC board when you have the cable oriented correctly, and
4513 that pin 1 on the TeleMini board is marked with a square pad
4514 while the other pins have round pads.
4519 Attach a battery to the TeleMini board.
4524 Plug the TeleDongle into your computer's USB port, and power
4530 Run AltosUI, and select 'Flash Image' from the File menu.
4535 Pick the TeleDongle device from the list, identifying it as the
4541 Select the image you want put on the TeleMini, which should have a
4542 name in the form telemini-v1.0-1.0.0.ihx. It should be visible
4543 in the default directory, if not you may have to poke around
4544 your system to find it.
4549 Make sure the configuration parameters are reasonable
4550 looking. If the serial number and/or RF configuration
4551 values aren't right, you'll need to change them.
4556 Hit the 'OK' button and the software should proceed to flash
4557 the TeleMini with new firmware, showing a progress bar.
4562 Confirm that the TeleMini board seems to have updated OK, which you
4563 can do by configuring it over the radio link through the TeleDongle, or
4564 letting it come up in “flight” mode and listening for telemetry.
4569 If something goes wrong, give it another try.
4575 <title>Updating TeleDongle Firmware</title>
4577 Updating TeleDongle's firmware is just like updating TeleMetrum or TeleMini
4578 firmware, but you use either a TeleMetrum or another TeleDongle as the programmer.
4580 <orderedlist inheritnum='inherit' numeration='arabic'>
4583 Find the 'programming cable' that you got as part of the starter
4584 kit, that has a red 8-pin MicroMaTch connector on one end and a
4585 red 4-pin MicroMaTch connector on the other end.
4590 Find the USB cable that you got as part of the starter kit, and
4591 plug the “mini” end in to the mating connector on TeleMetrum or TeleDongle.
4596 Take the 2 screws out of the TeleDongle case to get access
4597 to the circuit board.
4602 Plug the 8-pin end of the programming cable to the
4603 matching connector on the programmer, and the 4-pin end to the
4604 matching connector on the TeleDongle.
4605 Note that each MicroMaTch connector has an alignment pin that
4606 goes through a hole in the PC board when you have the cable
4612 Attach a battery to the TeleMetrum board if you're using one.
4617 Plug both the programmer and the TeleDongle into your computer's USB
4618 ports, and power up the programmer.
4623 Run AltosUI, and select 'Flash Image' from the File menu.
4628 Pick the programmer device from the list, identifying it as the
4634 Select the image you want put on the TeleDongle, which should have a
4635 name in the form teledongle-v0.2-1.0.0.ihx. It should be visible
4636 in the default directory, if not you may have to poke around
4637 your system to find it.
4642 Make sure the configuration parameters are reasonable
4643 looking. If the serial number and/or RF configuration
4644 values aren't right, you'll need to change them. The TeleDongle
4645 serial number is on the “bottom” of the circuit board, and can
4646 usually be read through the translucent blue plastic case without
4647 needing to remove the board from the case.
4652 Hit the 'OK' button and the software should proceed to flash
4653 the TeleDongle with new firmware, showing a progress bar.
4658 Confirm that the TeleDongle board seems to have updated OK, which you
4659 can do by plugging in to it over USB and using a terminal program
4660 to connect to the board and issue the 'v' command to check
4661 the version, etc. Once you're happy, remove the programming cable
4662 and put the cover back on the TeleDongle.
4667 If something goes wrong, give it another try.
4672 Be careful removing the programming cable from the locking 8-pin
4673 connector on TeleMetrum. You'll need a fingernail or perhaps a thin
4674 screwdriver or knife blade to gently pry the locking ears out
4675 slightly to extract the connector. We used a locking connector on
4676 TeleMetrum to help ensure that the cabling to companion boards
4677 used in a rocket don't ever come loose accidentally in flight.
4682 <title>Hardware Specifications</title>
4685 TeleMega Specifications
4690 Recording altimeter for model rocketry.
4695 Supports dual deployment and four auxiliary pyro channels
4696 (a total of 6 events).
4701 70cm 40mW ham-band transceiver for telemetry down-link.
4706 Barometric pressure sensor good to 100k feet MSL.
4711 1-axis high-g accelerometer for motor characterization, capable of
4717 9-axis IMU including integrated 3-axis accelerometer,
4718 3-axis gyroscope and 3-axis magnetometer.
4723 On-board, integrated uBlox Max 7 GPS receiver with 5Hz update rate capability.
4728 On-board 8 Megabyte non-volatile memory for flight data storage.
4733 USB interface for battery charging, configuration, and data recovery.
4738 Fully integrated support for Li-Po rechargeable batteries.
4743 Can use either main system Li-Po or optional separate pyro battery
4749 3.25 x 1.25 inch board designed to fit inside 38mm air-frame coupler tube.
4756 TeleMetrum v2 Specifications
4761 Recording altimeter for model rocketry.
4766 Supports dual deployment (can fire 2 ejection charges).
4771 70cm, 40mW ham-band transceiver for telemetry down-link.
4776 Barometric pressure sensor good to 100k feet MSL.
4781 1-axis high-g accelerometer for motor characterization, capable of
4787 On-board, integrated uBlox Max 7 GPS receiver with 5Hz update rate capability.
4792 On-board 8 Megabyte non-volatile memory for flight data storage.
4797 USB interface for battery charging, configuration, and data recovery.
4802 Fully integrated support for Li-Po rechargeable batteries.
4807 Uses Li-Po to fire e-matches, can be modified to support
4808 optional separate pyro battery if needed.
4813 2.75 x 1 inch board designed to fit inside 29mm air-frame coupler tube.
4819 <title>TeleMetrum v1 Specifications</title>
4823 Recording altimeter for model rocketry.
4828 Supports dual deployment (can fire 2 ejection charges).
4833 70cm, 10mW ham-band transceiver for telemetry down-link.
4838 Barometric pressure sensor good to 45k feet MSL.
4843 1-axis high-g accelerometer for motor characterization, capable of
4844 +/- 50g using default part.
4849 On-board, integrated GPS receiver with 5Hz update rate capability.
4854 On-board 1 megabyte non-volatile memory for flight data storage.
4859 USB interface for battery charging, configuration, and data recovery.
4864 Fully integrated support for Li-Po rechargeable batteries.
4869 Uses Li-Po to fire e-matches, can be modified to support
4870 optional separate pyro battery if needed.
4875 2.75 x 1 inch board designed to fit inside 29mm air-frame coupler tube.
4882 TeleMini v2.0 Specifications
4887 Recording altimeter for model rocketry.
4892 Supports dual deployment (can fire 2 ejection charges).
4897 70cm, 10mW ham-band transceiver for telemetry down-link.
4902 Barometric pressure sensor good to 100k feet MSL.
4907 On-board 1 megabyte non-volatile memory for flight data storage.
4912 USB interface for configuration, and data recovery.
4917 Support for Li-Po rechargeable batteries (using an
4918 external charger), or any 3.7-15V external battery.
4923 Uses Li-Po to fire e-matches, can be modified to support
4924 optional separate pyro battery if needed.
4929 1.5 x .8 inch board designed to fit inside 24mm air-frame coupler tube.
4936 TeleMini v1.0 Specifications
4941 Recording altimeter for model rocketry.
4946 Supports dual deployment (can fire 2 ejection charges).
4951 70cm, 10mW ham-band transceiver for telemetry down-link.
4956 Barometric pressure sensor good to 45k feet MSL.
4961 On-board 5 kilobyte non-volatile memory for flight data storage.
4966 RF interface for configuration, and data recovery.
4971 Support for Li-Po rechargeable batteries, using an external charger.
4976 Uses Li-Po to fire e-matches, can be modified to support
4977 optional separate pyro battery if needed.
4982 1.5 x .5 inch board designed to fit inside 18mm air-frame coupler tube.
4989 EasyMini Specifications
4994 Recording altimeter for model rocketry.
4999 Supports dual deployment (can fire 2 ejection charges).
5004 Barometric pressure sensor good to 100k feet MSL.
5009 On-board 1 megabyte non-volatile memory for flight data storage.
5014 USB interface for configuration, and data recovery.
5019 Support for Li-Po rechargeable batteries (using an
5020 external charger), or any 3.7-15V external battery.
5025 Uses Li-Po to fire e-matches, can be modified to support
5026 optional separate pyro battery if needed.
5031 1.5 x .8 inch board designed to fit inside 24mm air-frame coupler tube.
5040 <emphasis>TeleMetrum seems to shut off when disconnected from the
5041 computer.</emphasis> <?linebreak?>
5042 Make sure the battery is adequately charged. Remember the
5043 unit will pull more power than the USB port can deliver before the
5044 GPS enters “locked” mode. The battery charges best when TeleMetrum
5048 <emphasis>It's impossible to stop the TeleDongle when it's in “p” mode, I have
5049 to unplug the USB cable? </emphasis><?linebreak?>
5050 Make sure you have tried to “escape out” of
5051 this mode. If this doesn't work the reboot procedure for the
5052 TeleDongle *is* to simply unplug it. 'cu' however will retain it's
5053 outgoing buffer IF your “escape out” ('~~') does not work.
5054 At this point using either 'ao-view' (or possibly
5055 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
5059 <emphasis>The amber LED (on the TeleMetrum) lights up when both
5060 battery and USB are connected. Does this mean it's charging?
5061 </emphasis><?linebreak?>
5062 Yes, the yellow LED indicates the charging at the 'regular' rate.
5063 If the led is out but the unit is still plugged into a USB port,
5064 then the battery is being charged at a 'trickle' rate.
5067 <emphasis>There are no “dit-dah-dah-dit” sound or lights like the manual
5068 mentions?</emphasis><?linebreak?>
5069 That's the “pad” mode. Weak batteries might be the problem.
5070 It is also possible that the flight computer is horizontal and the
5072 is instead a “dit-dit” meaning 'idle'. For TeleMini, it's possible that
5073 it received a command packet which would have left it in “pad” mode.
5076 <emphasis>How do I save flight data?</emphasis><?linebreak?>
5077 Live telemetry is written to file(s) whenever AltosUI is connected
5078 to the TeleDongle. The file area defaults to ~/TeleMetrum
5079 but is easily changed using the menus in AltosUI. The files that
5080 are written end in '.telem'. The after-flight
5081 data-dumped files will end in .eeprom and represent continuous data
5082 unlike the .telem files that are subject to losses
5083 along the RF data path.
5084 See the above instructions on what and how to save the eeprom stored
5085 data after physically retrieving your altimeter. Make sure to save
5086 the on-board data after each flight; while the TeleMetrum can store
5087 multiple flights, you never know when you'll lose the altimeter...
5091 <title>Notes for Older Software</title>
5094 Before AltosUI was written, using Altus Metrum devices required
5095 some finesse with the Linux command line. There was a limited
5096 GUI tool, ao-view, which provided functionality similar to the
5097 Monitor Flight window in AltosUI, but everything else was a
5098 fairly 80's experience. This appendix includes documentation for
5099 using that software.
5103 Both TeleMetrum and TeleDongle can be directly communicated
5104 with using USB ports. The first thing you should try after getting
5105 both units plugged into to your computer's USB port(s) is to run
5106 'ao-list' from a terminal-window to see what port-device-name each
5107 device has been assigned by the operating system.
5108 You will need this information to access the devices via their
5109 respective on-board firmware and data using other command line
5110 programs in the AltOS software suite.
5113 TeleMini can be communicated with through a TeleDongle device
5114 over the radio link. When first booted, TeleMini listens for a
5115 TeleDongle device and if it receives a packet, it goes into
5116 'idle' mode. Otherwise, it goes into 'pad' mode and waits to be
5117 launched. The easiest way to get it talking is to start the
5118 communication link on the TeleDongle and the power up the
5122 To access the device's firmware for configuration you need a terminal
5123 program such as you would use to talk to a modem. The software
5124 authors prefer using the program 'cu' which comes from the UUCP package
5125 on most Unix-like systems such as Linux. An example command line for
5126 cu might be 'cu -l /dev/ttyACM0', substituting the correct number
5127 indicated from running the
5128 ao-list program. Another reasonable terminal program for Linux is
5129 'cutecom'. The default 'escape'
5130 character used by CU (i.e. the character you use to
5131 issue commands to cu itself instead of sending the command as input
5132 to the connected device) is a '~'. You will need this for use in
5133 only two different ways during normal operations. First is to exit
5134 the program by sending a '~.' which is called a 'escape-disconnect'
5135 and allows you to close-out from 'cu'. The
5136 second use will be outlined later.
5139 All of the Altus Metrum devices share the concept of a two level
5140 command set in their firmware.
5141 The first layer has several single letter commands. Once
5142 you are using 'cu' (or 'cutecom') sending (typing) a '?'
5143 returns a full list of these
5144 commands. The second level are configuration sub-commands accessed
5145 using the 'c' command, for
5146 instance typing 'c?' will give you this second level of commands
5147 (all of which require the
5148 letter 'c' to access). Please note that most configuration options
5149 are stored only in Flash memory; TeleDongle doesn't provide any storage
5150 for these options and so they'll all be lost when you unplug it.
5153 Try setting these configuration ('c' or second level menu) values. A good
5154 place to start is by setting your call sign. By default, the boards
5155 use 'N0CALL' which is cute, but not exactly legal!
5156 Spend a few minutes getting comfortable with the units, their
5157 firmware, and 'cu' (or possibly 'cutecom').
5158 For instance, try to send
5159 (type) a 'c r 2' and verify the channel change by sending a 'c s'.
5160 Verify you can connect and disconnect from the units while in your
5161 terminal program by sending the escape-disconnect mentioned above.
5164 To set the radio frequency, use the 'c R' command to specify the
5165 radio transceiver configuration parameter. This parameter is computed
5166 using the desired frequency, 'F', the radio calibration parameter, 'C' (showed by the 'c s' command) and
5167 the standard calibration reference frequency, 'S', (normally 434.550MHz):
5171 Round the result to the nearest integer value.
5172 As with all 'c' sub-commands, follow this with a 'c w' to write the
5173 change to the parameter block in the on-board flash on
5174 your altimeter board if you want the change to stay in place across reboots.
5177 To set the apogee delay, use the 'c d' command.
5178 As with all 'c' sub-commands, follow this with a 'c w' to write the
5179 change to the parameter block in the on-board DataFlash chip.
5182 To set the main deployment altitude, use the 'c m' command.
5183 As with all 'c' sub-commands, follow this with a 'c w' to write the
5184 change to the parameter block in the on-board DataFlash chip.
5187 To calibrate the radio frequency, connect the UHF antenna port to a
5188 frequency counter, set the board to 434.550MHz, and use the 'C'
5189 command to generate a CW carrier. Wait for the transmitter temperature
5190 to stabilize and the frequency to settle down.
5191 Then, divide 434.550 MHz by the
5192 measured frequency and multiply by the current radio cal value show
5193 in the 'c s' command. For an unprogrammed board, the default value
5194 is 1186611 for cc1111 based products and 7119667 for cc1120
5195 based products. Take the resulting integer and program it using the 'c f'
5196 command. Testing with the 'C' command again should show a carrier
5197 within a few tens of Hertz of the intended frequency.
5198 As with all 'c' sub-commands, follow this with a 'c w' to write the
5199 change to the configuration memory.
5202 Note that the 'reboot' command, which is very useful on the altimeters,
5203 will likely just cause problems with the dongle. The *correct* way
5204 to reset the dongle is just to unplug and re-plug it.
5207 A fun thing to do at the launch site and something you can do while
5208 learning how to use these units is to play with the radio link access
5209 between an altimeter and the TeleDongle. Be aware that you *must* create
5210 some physical separation between the devices, otherwise the link will
5211 not function due to signal overload in the receivers in each device.
5214 Now might be a good time to take a break and read the rest of this
5215 manual, particularly about the two “modes” that the altimeters
5216 can be placed in. TeleMetrum uses the position of the device when booting
5217 up will determine whether the unit is in “pad” or “idle” mode. TeleMini
5218 enters “idle” mode when it receives a command packet within the first 5 seconds
5219 of being powered up, otherwise it enters “pad” mode.
5222 You can access an altimeter in idle mode from the TeleDongle's USB
5223 connection using the radio link
5224 by issuing a 'p' command to the TeleDongle. Practice connecting and
5225 disconnecting ('~~' while using 'cu') from the altimeter. If
5226 you cannot escape out of the “p” command, (by using a '~~' when in
5227 CU) then it is likely that your kernel has issues. Try a newer version.
5230 Using this radio link allows you to configure the altimeter, test
5231 fire e-matches and igniters from the flight line, check pyro-match
5232 continuity and so forth. You can leave the unit turned on while it
5233 is in 'idle mode' and then place the
5234 rocket vertically on the launch pad, walk away and then issue a
5235 reboot command. The altimeter will reboot and start sending data
5236 having changed to the “pad” mode. If the TeleDongle is not receiving
5237 this data, you can disconnect 'cu' from the TeleDongle using the
5238 procedures mentioned above and THEN connect to the TeleDongle from
5239 inside 'ao-view'. If this doesn't work, disconnect from the
5240 TeleDongle, unplug it, and try again after plugging it back in.
5243 In order to reduce the chance of accidental firing of pyrotechnic
5244 charges, the command to fire a charge is intentionally somewhat
5245 difficult to type, and the built-in help is slightly cryptic to
5246 prevent accidental echoing of characters from the help text back at
5247 the board from firing a charge. The command to fire the apogee
5248 drogue charge is 'i DoIt drogue' and the command to fire the main
5249 charge is 'i DoIt main'.
5252 On TeleMetrum, the GPS will eventually find enough satellites, lock in on them,
5253 and 'ao-view' will both auditorily announce and visually indicate
5255 Now you can launch knowing that you have a good data path and
5256 good satellite lock for flight data and recovery. Remember
5257 you MUST tell ao-view to connect to the TeleDongle explicitly in
5258 order for ao-view to be able to receive data.
5261 The altimeters provide RDF (radio direction finding) tones on
5262 the pad, during descent and after landing. These can be used to
5263 locate the rocket using a directional antenna; the signal
5264 strength providing an indication of the direction from receiver to rocket.
5267 TeleMetrum also provides GPS tracking data, which can further simplify
5268 locating the rocket once it has landed. (The last good GPS data
5269 received before touch-down will be on the data screen of 'ao-view'.)
5272 Once you have recovered the rocket you can download the eeprom
5273 contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over
5274 either a USB cable or over the radio link using TeleDongle.
5275 And by following the man page for 'ao-postflight' you can create
5276 various data output reports, graphs, and even KML data to see the
5277 flight trajectory in Google-earth. (Moving the viewing angle making
5278 sure to connect the yellow lines while in Google-earth is the proper
5282 As for ao-view.... some things are in the menu but don't do anything
5283 very useful. The developers have stopped working on ao-view to focus
5284 on a new, cross-platform ground station program. So ao-view may or
5285 may not be updated in the future. Mostly you just use
5286 the Log and Device menus. It has a wonderful display of the incoming
5287 flight data and I am sure you will enjoy what it has to say to you
5288 once you enable the voice output!
5292 <title>Drill Templates</title>
5294 These images, when printed, provide precise templates for the
5295 mounting holes in Altus Metrum flight computers
5298 <title>TeleMega template</title>
5300 TeleMega has overall dimensions of 1.250 x 3.250 inches, and
5301 the mounting holes are sized for use with 4-40 or M3 screws.
5304 <mediaobject id="TeleMegaTemplate">
5306 <imagedata format="SVG" fileref="telemega.svg"
5307 scalefit="0" scale="100" align="center" />
5313 <title>TeleMetrum template</title>
5315 TeleMetrum has overall dimensions of 1.000 x 2.750 inches, and the
5316 mounting holes are sized for use with 4-40 or M3 screws.
5319 <mediaobject id="TeleMetrumTemplate">
5321 <imagedata format="SVG" fileref="telemetrum.svg"
5322 scalefit="0" scale="100" align="center" />
5328 <title>TeleMini v2/EasyMini template</title>
5330 TeleMini v2 and EasyMini have overall dimensions of 0.800 x 1.500 inches, and the
5331 mounting holes are sized for use with 4-40 or M3 screws.
5334 <mediaobject id="MiniTemplate">
5336 <imagedata format="SVG" fileref="easymini.svg"
5337 scalefit="0" scale="100" align="center" />
5343 <title>TeleMini v1 template</title>
5345 TeleMini has overall dimensions of 0.500 x 1.500 inches, and the
5346 mounting holes are sized for use with 2-56 or M2 screws.
5349 <mediaobject id="TeleMiniTemplate">
5351 <imagedata format="SVG" fileref="telemini.svg"
5352 scalefit="0" scale="100" align="center" />
5359 <title>Calibration</title>
5361 There are only two calibrations required for TeleMetrum and
5362 TeleMega, and only one for TeleDongle, TeleMini and EasyMini.
5363 All boards are shipped from the factory pre-calibrated, but
5364 the procedures are documented here in case they are ever
5365 needed. Re-calibration is not supported by AltosUI, you must
5366 connect to the board with a serial terminal program and
5367 interact directly with the on-board command interpreter to
5371 <title>Radio Frequency</title>
5373 The radio frequency is synthesized from a clock based on the
5374 crystal on the board. The actual frequency of this oscillator
5375 must be measured to generate a calibration constant. While our
5377 bandwidth is wide enough to allow boards to communicate even when
5378 their oscillators are not on exactly the same frequency, performance
5379 is best when they are closely matched.
5380 Radio frequency calibration requires a calibrated frequency counter.
5381 Fortunately, once set, the variation in frequency due to aging and
5382 temperature changes is small enough that re-calibration by customers
5383 should generally not be required.
5386 To calibrate the radio frequency, connect the UHF antenna
5387 port to a frequency counter, set the board to 434.550MHz,
5388 and use the 'C' command in the on-board command interpreter
5389 to generate a CW carrier. For USB-enabled boards, this is
5390 best done over USB. For TeleMini v1, note that the only way
5391 to escape the 'C' command is via power cycle since the board
5392 will no longer be listening for commands once it starts
5393 generating a CW carrier.
5396 Wait for the transmitter temperature to stabilize and the frequency
5397 to settle down. Then, divide 434.550 MHz by the
5398 measured frequency and multiply by the current radio cal value show
5399 in the 'c s' command. For an unprogrammed board, the default value
5400 is 1186611. Take the resulting integer and program it using the 'c f'
5401 command. Testing with the 'C' command again should show a carrier
5402 within a few tens of Hertz of the intended frequency.
5403 As with all 'c' sub-commands, follow this with a 'c w' to write the
5404 change to the parameter block in the on-board storage chip.
5407 Note that any time you re-do the radio frequency calibration, the
5408 radio frequency is reset to the default 434.550 Mhz. If you want
5409 to use another frequency, you will have to set that again after
5410 calibration is completed.
5414 <title>TeleMetrum and TeleMega Accelerometers</title>
5416 While barometric sensors are factory-calibrated,
5417 accelerometers are not, and so each must be calibrated once
5418 installed in a flight computer. Explicitly calibrating the
5419 accelerometers also allows us to load any compatible device.
5420 We perform a two-point calibration using gravity.
5423 To calibrate the acceleration sensor, use the 'c a 0' command. You
5424 will be prompted to orient the board vertically with the UHF antenna
5425 up and press a key, then to orient the board vertically with the
5426 UHF antenna down and press a key. Note that the accuracy of this
5427 calibration depends primarily on how perfectly vertical and still
5428 the board is held during the cal process. As with all 'c'
5429 sub-commands, follow this with a 'c w' to write the
5430 change to the parameter block in the on-board DataFlash chip.
5433 The +1g and -1g calibration points are included in each telemetry
5434 frame and are part of the header stored in onboard flash to be
5435 downloaded after flight. We always store and return raw ADC
5436 samples for each sensor... so nothing is permanently “lost” or
5437 “damaged” if the calibration is poor.
5440 In the unlikely event an accel cal goes badly, it is possible
5441 that TeleMetrum or TeleMega may always come up in 'pad mode'
5442 and as such not be listening to either the USB or radio link.
5443 If that happens, there is a special hook in the firmware to
5444 force the board back in to 'idle mode' so you can re-do the
5445 cal. To use this hook, you just need to ground the SPI clock
5446 pin at power-on. This pin is available as pin 2 on the 8-pin
5447 companion connector, and pin 1 is ground. So either
5448 carefully install a fine-gauge wire jumper between the two
5449 pins closest to the index hole end of the 8-pin connector, or
5450 plug in the programming cable to the 8-pin connector and use
5451 a small screwdriver or similar to short the two pins closest
5452 to the index post on the 4-pin end of the programming cable,
5453 and power up the board. It should come up in 'idle mode'
5454 (two beeps), allowing a re-cal.
5459 <title>Release Notes</title>
5461 <title>Version 1.4</title>
5463 xmlns:xi="http://www.w3.org/2001/XInclude"
5464 href="release-notes-1.4.xsl"
5465 xpointer="xpointer(/article/*)"/>
5468 <title>Version 1.3.2</title>
5470 xmlns:xi="http://www.w3.org/2001/XInclude"
5471 href="release-notes-1.3.2.xsl"
5472 xpointer="xpointer(/article/*)"/>
5475 <title>Version 1.3.1</title>
5477 xmlns:xi="http://www.w3.org/2001/XInclude"
5478 href="release-notes-1.3.1.xsl"
5479 xpointer="xpointer(/article/*)"/>
5482 <title>Version 1.3</title>
5484 xmlns:xi="http://www.w3.org/2001/XInclude"
5485 href="release-notes-1.3.xsl"
5486 xpointer="xpointer(/article/*)"/>
5489 <title>Version 1.2.1</title>
5491 xmlns:xi="http://www.w3.org/2001/XInclude"
5492 href="release-notes-1.2.1.xsl"
5493 xpointer="xpointer(/article/*)"/>
5496 <title>Version 1.2</title>
5498 xmlns:xi="http://www.w3.org/2001/XInclude"
5499 href="release-notes-1.2.xsl"
5500 xpointer="xpointer(/article/*)"/>
5503 <title>Version 1.1.1</title>
5505 xmlns:xi="http://www.w3.org/2001/XInclude"
5506 href="release-notes-1.1.1.xsl"
5507 xpointer="xpointer(/article/*)"/>
5510 <title>Version 1.1</title>
5512 xmlns:xi="http://www.w3.org/2001/XInclude"
5513 href="release-notes-1.1.xsl"
5514 xpointer="xpointer(/article/*)"/>
5517 <title>Version 1.0.1</title>
5519 xmlns:xi="http://www.w3.org/2001/XInclude"
5520 href="release-notes-1.0.1.xsl"
5521 xpointer="xpointer(/article/*)"/>
5524 <title>Version 0.9.2</title>
5526 xmlns:xi="http://www.w3.org/2001/XInclude"
5527 href="release-notes-0.9.2.xsl"
5528 xpointer="xpointer(/article/*)"/>
5531 <title>Version 0.9</title>
5533 xmlns:xi="http://www.w3.org/2001/XInclude"
5534 href="release-notes-0.9.xsl"
5535 xpointer="xpointer(/article/*)"/>
5538 <title>Version 0.8</title>
5540 xmlns:xi="http://www.w3.org/2001/XInclude"
5541 href="release-notes-0.8.xsl"
5542 xpointer="xpointer(/article/*)"/>
5545 <title>Version 0.7.1</title>
5547 xmlns:xi="http://www.w3.org/2001/XInclude"
5548 href="release-notes-0.7.1.xsl"
5549 xpointer="xpointer(/article/*)"/>
5554 <!-- LocalWords: Altusmetrum
projects / fw / altos / blob