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2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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5 <title>The Altus Metrum System</title>
6 <subtitle>An Owner's Manual for TeleMetrum, TeleMini and TeleDongle Devices</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 This document is released under the terms of the
31 <ulink url="http://creativecommons.org/licenses/by-sa/3.0/">
32 Creative Commons ShareAlike 3.0
39 <revnumber>1.0</revnumber>
40 <date>24 August 2011</date>
42 Updated for software version 1.0. Note that 1.0 represents a
43 telemetry format change, meaning both ends of a link
44 (TeleMetrum/TeleMini and TeleDongle) must be updated or
45 communications will fail.
49 <revnumber>0.9</revnumber>
50 <date>18 January 2011</date>
52 Updated for software version 0.9. Note that 0.9 represents a
53 telemetry format change, meaning both ends of a link (TeleMetrum and
54 TeleDongle) must be updated or communications will fail.
58 <revnumber>0.8</revnumber>
59 <date>24 November 2010</date>
60 <revremark>Updated for software version 0.8 </revremark>
66 Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing "The
67 Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter
68 Kit" which formed the basis of the original Getting Started chapter
69 in this book. Bob was one of our first customers for a production
70 TeleMetrum, and his continued enthusiasm and contributions
71 are immensely gratifying and highly appreciated!
74 And thanks to Anthony (AJ) Towns for major contributions including
75 the AltosUI graphing and site map code and associated documentation.
76 Free software means that our customers and friends can become our
77 collaborators, and we certainly appreciate this level of
81 Have fun using these products, and we hope to meet all of you
82 out on the rocket flight line somewhere.
85 NAR #87103, TRA #12201
88 NAR #88757, TRA #12200
93 <title>Introduction and Overview</title>
95 Welcome to the Altus Metrum community! Our circuits and software reflect
96 our passion for both hobby rocketry and Free Software. We hope their
97 capabilities and performance will delight you in every way, but by
98 releasing all of our hardware and software designs under open licenses,
99 we also hope to empower you to take as active a role in our collective
103 The first device created for our community was TeleMetrum, a dual
104 deploy altimeter with fully integrated GPS and radio telemetry
105 as standard features, and a "companion interface" that will
106 support optional capabilities in the future.
109 The newest device is TeleMini, a dual deploy altimeter with
110 radio telemetry and radio direction finding. This device is only
111 13mm by 38mm (½ inch by 1½ inches) and can fit easily in an 18mm air-frame.
114 Complementing TeleMetrum and TeleMini is TeleDongle, a USB to RF
115 interface for communicating with the altimeters. Combined with your
116 choice of antenna and
117 notebook computer, TeleDongle and our associated user interface software
118 form a complete ground station capable of logging and displaying in-flight
119 telemetry, aiding rocket recovery, then processing and archiving flight
120 data for analysis and review.
123 More products will be added to the Altus Metrum family over time, and
124 we currently envision that this will be a single, comprehensive manual
125 for the entire product family.
129 <title>Getting Started</title>
131 The first thing to do after you check the inventory of parts in your
132 "starter kit" is to charge the battery.
135 The TeleMetrum battery can be charged by plugging it into the
136 corresponding socket of the TeleMetrum and then using the USB A to
138 cable to plug the TeleMetrum into your computer's USB socket. The
139 TeleMetrum circuitry will charge the battery whenever it is plugged
140 in, because the TeleMetrum's on-off switch does NOT control the
144 When the GPS chip is initially searching for
145 satellites, TeleMetrum will consume more current than it can pull
146 from the USB port, so the battery must be attached in order to get
147 satellite lock. Once GPS is locked, the current consumption goes back
148 down enough to enable charging while
149 running. So it's a good idea to fully charge the battery as your
150 first item of business so there is no issue getting and maintaining
151 satellite lock. The yellow charge indicator led will go out when the
152 battery is nearly full and the charger goes to trickle charge. It
153 can take several hours to fully recharge a deeply discharged battery.
156 The TeleMini battery can be charged by disconnecting it from the
157 TeleMini board and plugging it into a standalone battery charger
158 board, and connecting that via a USB cable to a laptop or other USB
162 The other active device in the starter kit is the TeleDongle USB to
163 RF interface. If you plug it in to your Mac or Linux computer it should
164 "just work", showing up as a serial port device. Windows systems need
165 driver information that is part of the AltOS download to know that the
166 existing USB modem driver will work. We therefore recommend installing
167 our software before plugging in TeleDongle if you are using a Windows
168 computer. If you are using Linux and are having problems, try moving
169 to a fresher kernel (2.6.33 or newer), as the USB serial driver had
170 ugly bugs in some earlier versions.
173 Next you should obtain and install the AltOS software. These include
174 the AltosUI ground station program, current firmware images for
175 TeleMetrum, TeleMini and TeleDongle, and a number of standalone
176 utilities that are rarely needed. Pre-built binary packages are
177 available for Linux, Microsoft Windows, and recent MacOSX versions.
178 Full source code and build instructions are also available.
179 The latest version may always be downloaded from
180 <ulink url="http://altusmetrum.org/AltOS"/>.
184 <title>Handling Precautions</title>
186 All Altus Metrum products are sophisticated electronic devices.
187 When handled gently and properly installed in an air-frame, they
188 will deliver impressive results. However, like all electronic
189 devices, there are some precautions you must take.
192 The Lithium Polymer rechargeable batteries have an
193 extraordinary power density. This is great because we can fly with
194 much less battery mass than if we used alkaline batteries or previous
195 generation rechargeable batteries... but if they are punctured
196 or their leads are allowed to short, they can and will release their
198 Thus we recommend that you take some care when handling our batteries
199 and consider giving them some extra protection in your air-frame. We
200 often wrap them in suitable scraps of closed-cell packing foam before
201 strapping them down, for example.
204 The barometric sensors used on both TeleMetrum and TeleMini are
205 sensitive to sunlight. In normal TeleMetrum mounting situations, it
206 and all of the other surface mount components
207 are "down" towards whatever the underlying mounting surface is, so
208 this is not normally a problem. Please consider this, though, when
209 designing an installation, for example, in an air-frame with a
210 see-through plastic payload bay. It is particularly important to
211 consider this with TeleMini, both because the baro sensor is on the
212 "top" of the board, and because many model rockets with payload bays
213 use clear plastic for the payload bay! Replacing these with an opaque
214 cardboard tube, painting them, or wrapping them with a layer of masking
215 tape are all reasonable approaches to keep the sensor out of direct
219 The barometric sensor sampling port must be able to "breathe",
220 both by not being covered by foam or tape or other materials that might
221 directly block the hole on the top of the sensor, and also by having a
222 suitable static vent to outside air.
225 As with all other rocketry electronics, Altus Metrum altimeters must
226 be protected from exposure to corrosive motor exhaust and ejection
231 <title>Hardware Overview</title>
233 TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to
234 fit inside coupler for 29mm air-frame tubing, but using it in a tube that
235 small in diameter may require some creativity in mounting and wiring
236 to succeed! The presence of an accelerometer means TeleMetrum should
237 be aligned along the flight axis of the airframe, and by default the 1/4
238 wave UHF wire antenna should be on the nose-cone end of the board. The
239 antenna wire is about 7 inches long, and wiring for a power switch and
240 the e-matches for apogee and main ejection charges depart from the
241 fin can end of the board, meaning an ideal "simple" avionics
242 bay for TeleMetrum should have at least 10 inches of interior length.
245 TeleMini is a 0.5 inch by 1.5 inch circuit board. It was designed to
246 fit inside an 18mm air-frame tube, but using it in a tube that
247 small in diameter may require some creativity in mounting and wiring
248 to succeed! Since there is no accelerometer, TeleMini can be mounted
249 in any convenient orientation. The default 1/4
250 wave UHF wire antenna attached to the center of one end of
251 the board is about 7 inches long, and wiring for a power switch and
252 the e-matches for apogee and main ejection charges depart from the
253 other end of the board, meaning an ideal "simple" avionics
254 bay for TeleMini should have at least 9 inches of interior length.
257 A typical TeleMetrum or TeleMini installation involves attaching
258 only a suitable Lithium Polymer battery, a single pole switch for
259 power on/off, and two pairs of wires connecting e-matches for the
260 apogee and main ejection charges.
263 By default, we use the unregulated output of the Li-Po battery directly
264 to fire ejection charges. This works marvelously with standard
265 low-current e-matches like the J-Tek from MJG Technologies, and with
266 Quest Q2G2 igniters. However, if you want or need to use a separate
267 pyro battery, check out the "External Pyro Battery" section in this
268 manual for instructions on how to wire that up. The altimeters are
269 designed to work with an external pyro battery of no more than 15 volts.
272 Ejection charges are wired directly to the screw terminal block
273 at the aft end of the altimeter. You'll need a very small straight
274 blade screwdriver for these screws, such as you might find in a
275 jeweler's screwdriver set.
278 TeleMetrum also uses the screw terminal block for the power
279 switch leads. On TeleMini, the power switch leads are soldered
280 directly to the board and can be connected directly to a switch.
283 For most air-frames, the integrated antennas are more than
284 adequate. However, if you are installing in a carbon-fiber or
285 metal electronics bay which is opaque to RF signals, you may need to
286 use off-board external antennas instead. In this case, you can
287 order an altimeter with an SMA connector for the UHF antenna
288 connection, and, on TeleMetrum, you can unplug the integrated GPS
289 antenna and select an appropriate off-board GPS antenna with
290 cable terminating in a U.FL connector.
294 <title>System Operation</title>
296 <title>Firmware Modes </title>
298 The AltOS firmware build for the altimeters has two
299 fundamental modes, "idle" and "flight". Which of these modes
300 the firmware operates in is determined at start up time. For
301 TeleMetrum, the mode is controlled by the orientation of the
302 rocket (well, actually the board, of course...) at the time
303 power is switched on. If the rocket is "nose up", then
304 TeleMetrum assumes it's on a rail or rod being prepared for
305 launch, so the firmware chooses flight mode. However, if the
306 rocket is more or less horizontal, the firmware instead enters
307 idle mode. Since TeleMini doesn't have an accelerometer we can
308 use to determine orientation, "idle" mode is selected when the
309 board receives a command packet within the first five seconds
310 of operation; if no packet is received, the board enters
314 At power on, you will hear three beeps or see three flashes
315 ("S" in Morse code for start up) and then a pause while
316 the altimeter completes initialization and self test, and decides
317 which mode to enter next.
320 In flight or "pad" mode, the altimeter engages the flight
321 state machine, goes into transmit-only mode on the RF link
322 sending telemetry, and waits for launch to be detected.
323 Flight mode is indicated by an "di-dah-dah-dit" ("P" for pad)
324 on the beeper or lights, followed by beeps or flashes
325 indicating the state of the pyrotechnic igniter continuity.
326 One beep/flash indicates apogee continuity, two beeps/flashes
327 indicate main continuity, three beeps/flashes indicate both
328 apogee and main continuity, and one longer "brap" sound or
329 rapidly alternating lights indicates no continuity. For a
330 dual deploy flight, make sure you're getting three beeps or
331 flashes before launching! For apogee-only or motor eject
332 flights, do what makes sense.
335 If idle mode is entered, you will hear an audible "di-dit" or see
336 two short flashes ("I" for idle), and the flight state machine is
337 disengaged, thus no ejection charges will fire. The altimeters also
338 listen on the RF link when in idle mode for requests sent via
339 TeleDongle. Commands can be issued to a TeleMetrum in idle mode
341 USB or the RF link equivalently. TeleMini only has the RF link.
342 Idle mode is useful for configuring the altimeter, for extracting data
343 from the on-board storage chip after flight, and for ground testing
347 One "neat trick" of particular value when TeleMetrum is used with
348 very large air-frames, is that you can power the board up while the
349 rocket is horizontal, such that it comes up in idle mode. Then you can
350 raise the air-frame to launch position, and issue a 'reset' command
351 via TeleDongle over the RF link to cause the altimeter to reboot and
352 come up in flight mode. This is much safer than standing on the top
353 step of a rickety step-ladder or hanging off the side of a launch
354 tower with a screw-driver trying to turn on your avionics before
361 TeleMetrum includes a complete GPS receiver. A complete explanation
362 of how GPS works is beyond the scope of this manual, but the bottom
363 line is that the TeleMetrum GPS receiver needs to lock onto at least
364 four satellites to obtain a solid 3 dimensional position fix and know
368 TeleMetrum provides backup power to the GPS chip any time a
369 battery is connected. This allows the receiver to "warm start" on
370 the launch rail much faster than if every power-on were a GPS
371 "cold start". In typical operations, powering up TeleMetrum
372 on the flight line in idle mode while performing final air-frame
373 preparation will be sufficient to allow the GPS receiver to cold
374 start and acquire lock. Then the board can be powered down during
375 RSO review and installation on a launch rod or rail. When the board
376 is turned back on, the GPS system should lock very quickly, typically
377 long before igniter installation and return to the flight line are
382 <title>Ground Testing </title>
384 An important aspect of preparing a rocket using electronic deployment
385 for flight is ground testing the recovery system. Thanks
386 to the bi-directional RF link central to the Altus Metrum system,
387 this can be accomplished in a TeleMetrum or TeleMini equipped rocket
388 with less work than you may be accustomed to with other systems. It
392 Just prep the rocket for flight, then power up the altimeter
393 in "idle" mode (placing air-frame horizontal for TeleMetrum or
394 selected the Configure Altimeter tab for TeleMini). This will cause
395 the firmware to go into "idle" mode, in which the normal flight
396 state machine is disabled and charges will not fire without
397 manual command. You can now command the altimeter to fire the apogee
398 or main charges from a safe distance using your computer and
399 TeleDongle and the Fire Igniter tab to complete ejection testing.
403 <title>Radio Link </title>
405 The chip our boards are based on incorporates an RF transceiver, but
406 it's not a full duplex system... each end can only be transmitting or
407 receiving at any given moment. So we had to decide how to manage the
411 By design, the altimeter firmware listens for an RF connection when
412 it's in "idle mode", which
413 allows us to use the RF link to configure the rocket, do things like
414 ejection tests, and extract data after a flight without having to
415 crack open the air-frame. However, when the board is in "flight
416 mode", the altimeter only
417 transmits and doesn't listen at all. That's because we want to put
418 ultimate priority on event detection and getting telemetry out of
419 the rocket and out over
420 the RF link in case the rocket crashes and we aren't able to extract
424 We don't use a 'normal packet radio' mode like APRS because they're
425 just too inefficient. The GFSK modulation we use is FSK with the
426 base-band pulses passed through a
427 Gaussian filter before they go into the modulator to limit the
428 transmitted bandwidth. When combined with the hardware forward error
429 correction support in the cc1111 chip, this allows us to have a very
430 robust 38.4 kilobit data link with only 10 milliwatts of transmit
431 power, a whip antenna in the rocket, and a hand-held Yagi on the
432 ground. We've had flights to above 21k feet AGL with great reception,
433 and calculations suggest we should be good to well over 40k feet AGL
434 with a 5-element yagi on the ground. We hope to fly boards to higher
435 altitudes over time, and would of course appreciate customer feedback
436 on performance in higher altitude flights!
440 <title>Configurable Parameters</title>
442 Configuring an Altus Metrum altimeter for flight is very
443 simple. Even on our baro-only TeleMini board, the use of a Kalman
444 filter means there is no need to set a "mach delay". The few
445 configurable parameters can all be set using AltosUI over USB or
446 or RF link via TeleDongle.
449 <title>Radio Frequencies</title>
451 The Altus Metrum boards support frequencies in the 70cm
452 band. By default, the configuration interface provides a
453 list of 10 common frequencies in 100kHz channels starting at
454 434.550MHz. However, the firmware supports use of
455 any 50kHz multiple within the 70cm band. At any given
456 launch, we highly recommend coordinating who will use each
457 frequency and when to avoid interference. And of course, both
458 altimeter and TeleDongle must be configured to the same
459 frequency to successfully communicate with each other.
462 To set the radio frequency, use the 'c R' command to specify the
463 radio transceiver configuration parameter. This parameter is computed
464 using the desired frequency, 'F', the radio calibration parameter, 'C' (showed by the 'c s' command) and
465 the standard calibration reference frequency, 'S', (normally 434.550MHz):
469 Round the result to the nearest integer value.
470 As with all 'c' sub-commands, follow this with a 'c w' to write the
471 change to the parameter block in the on-board flash on
472 your altimeter board if you want the change to stay in place across reboots.
476 <title>Apogee Delay</title>
478 Apogee delay is the number of seconds after the altimeter detects flight
479 apogee that the drogue charge should be fired. In most cases, this
480 should be left at the default of 0. However, if you are flying
481 redundant electronics such as for an L3 certification, you may wish
482 to set one of your altimeters to a positive delay so that both
483 primary and backup pyrotechnic charges do not fire simultaneously.
486 To set the apogee delay, use the 'c d' command.
487 As with all 'c' sub-commands, follow this with a 'c w' to write the
488 change to the parameter block in the on-board DataFlash chip.
491 Please note that the Altus Metrum apogee detection algorithm
492 fires exactly at apogee. If you are also flying an
493 altimeter like the PerfectFlite MAWD, which only supports
494 selecting 0 or 1 seconds of apogee delay, you may wish to
495 set the MAWD to 0 seconds delay and set the TeleMetrum to
496 fire your backup 2 or 3 seconds later to avoid any chance of
497 both charges firing simultaneously. We've flown several
498 air-frames this way quite happily, including Keith's
503 <title>Main Deployment Altitude</title>
505 By default, the altimeter will fire the main deployment charge at an
506 elevation of 250 meters (about 820 feet) above ground. We think this
507 is a good elevation for most air-frames, but feel free to change this
508 to suit. In particular, if you are flying two altimeters, you may
510 deployment elevation for the backup altimeter to be something lower
511 than the primary so that both pyrotechnic charges don't fire
515 To set the main deployment altitude, use the 'c m' command.
516 As with all 'c' sub-commands, follow this with a 'c w' to write the
517 change to the parameter block in the on-board DataFlash chip.
522 <title>Calibration</title>
524 There are only two calibrations required for a TeleMetrum board, and
525 only one for TeleDongle and TeleMini.
528 <title>Radio Frequency</title>
530 The radio frequency is synthesized from a clock based on the 48 MHz
531 crystal on the board. The actual frequency of this oscillator must be
532 measured to generate a calibration constant. While our GFSK modulation
533 bandwidth is wide enough to allow boards to communicate even when
534 their oscillators are not on exactly the same frequency, performance
535 is best when they are closely matched.
536 Radio frequency calibration requires a calibrated frequency counter.
537 Fortunately, once set, the variation in frequency due to aging and
538 temperature changes is small enough that re-calibration by customers
539 should generally not be required.
542 To calibrate the radio frequency, connect the UHF antenna port to a
543 frequency counter, set the board to 434.550MHz, and use the 'C'
544 command to generate a CW carrier. Wait for the transmitter temperature
545 to stabilize and the frequency to settle down.
546 Then, divide 434.550 MHz by the
547 measured frequency and multiply by the current radio cal value show
548 in the 'c s' command. For an unprogrammed board, the default value
549 is 1186611. Take the resulting integer and program it using the 'c f'
550 command. Testing with the 'C' command again should show a carrier
551 within a few tens of Hertz of the intended frequency.
552 As with all 'c' sub-commands, follow this with a 'c w' to write the
553 change to the parameter block in the on-board DataFlash chip.
556 when the radio calibration value is changed, the radio
557 frequency value is reset to the same value, so you'll need
558 to recompute and reset the radio frequency value using the
559 new radio calibration value.
563 <title>TeleMetrum Accelerometer</title>
565 The TeleMetrum accelerometer we use has its own 5 volt power supply and
566 the output must be passed through a resistive voltage divider to match
567 the input of our 3.3 volt ADC. This means that unlike the barometric
568 sensor, the output of the acceleration sensor is not ratio-metric to
569 the ADC converter, and calibration is required. We also support the
570 use of any of several accelerometers from a Freescale family that
571 includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity,
572 a simple 2-point calibration yields acceptable results capturing both
573 the different sensitivities and ranges of the different accelerometer
574 parts and any variation in power supply voltages or resistor values
575 in the divider network.
578 To calibrate the acceleration sensor, use the 'c a 0' command. You
579 will be prompted to orient the board vertically with the UHF antenna
580 up and press a key, then to orient the board vertically with the
581 UHF antenna down and press a key.
582 As with all 'c' sub-commands, follow this with a 'c w' to write the
583 change to the parameter block in the on-board DataFlash chip.
586 The +1g and -1g calibration points are included in each telemetry
587 frame and are part of the header extracted by ao-dumplog after flight.
588 Note that we always store and return raw ADC samples for each
589 sensor... nothing is permanently "lost" or "damaged" if the
593 In the unlikely event an accel cal that goes badly, it is possible
594 that TeleMetrum may always come up in 'pad mode' and as such not be
595 listening to either the USB or radio interfaces. If that happens,
596 there is a special hook in the firmware to force the board back
597 in to 'idle mode' so you can re-do the cal. To use this hook, you
598 just need to ground the SPI clock pin at power-on. This pin is
599 available as pin 2 on the 8-pin companion connector, and pin 1 is
600 ground. So either carefully install a fine-gauge wire jumper
601 between the two pins closest to the index hole end of the 8-pin
602 connector, or plug in the programming cable to the 8-pin connector
603 and use a small screwdriver or similar to short the two pins closest
604 to the index post on the 4-pin end of the programming cable, and
605 power up the board. It should come up in 'idle mode' (two beeps).
610 <title>Updating Device Firmware</title>
612 The big conceptual thing to realize is that you have to use a
613 TeleDongle as a programmer to update a TeleMetrum or TeleMini,
614 and a TeleMetrum or other TeleDongle to program the TeleDongle
615 Due to limited memory resources in the cc1111, we don't support
616 programming directly over USB.
619 You may wish to begin by ensuring you have current firmware images.
620 These are distributed as part of the AltOS software bundle that
621 also includes the AltosUI ground station program. Newer ground
622 station versions typically work fine with older firmware versions,
623 so you don't need to update your devices just to try out new
624 software features. You can always download the most recent
625 version from <ulink url="http://www.altusmetrum.org/AltOS/"/>.
628 We recommend updating the altimeter first, before updating TeleDongle.
631 <title>Updating TeleMetrum Firmware</title>
632 <orderedlist inheritnum='inherit' numeration='arabic'>
634 Find the 'programming cable' that you got as part of the starter
635 kit, that has a red 8-pin MicroMaTch connector on one end and a
636 red 4-pin MicroMaTch connector on the other end.
639 Take the 2 screws out of the TeleDongle case to get access
640 to the circuit board.
643 Plug the 8-pin end of the programming cable to the
644 matching connector on the TeleDongle, and the 4-pin end to the
645 matching connector on the TeleMetrum.
646 Note that each MicroMaTch connector has an alignment pin that
647 goes through a hole in the PC board when you have the cable
651 Attach a battery to the TeleMetrum board.
654 Plug the TeleDongle into your computer's USB port, and power
658 Run AltosUI, and select 'Flash Image' from the File menu.
661 Pick the TeleDongle device from the list, identifying it as the
665 Select the image you want put on the TeleMetrum, which should have a
666 name in the form telemetrum-v1.1-1.0.0.ihx. It should be visible
667 in the default directory, if not you may have to poke around
668 your system to find it.
671 Make sure the configuration parameters are reasonable
672 looking. If the serial number and/or RF configuration
673 values aren't right, you'll need to change them.
676 Hit the 'OK' button and the software should proceed to flash
677 the TeleMetrum with new firmware, showing a progress bar.
680 Confirm that the TeleMetrum board seems to have updated OK, which you
681 can do by plugging in to it over USB and using a terminal program
682 to connect to the board and issue the 'v' command to check
686 If something goes wrong, give it another try.
691 <title>Updating TeleMini Firmware</title>
692 <orderedlist inheritnum='inherit' numeration='arabic'>
694 You'll need a special 'programming cable' to reprogram the
695 TeleMini. It's available on the Altus Metrum web store, or
696 you can make your own using an 8-pin MicroMaTch connector on
697 one end and a set of four pins on the other.
700 Take the 2 screws out of the TeleDongle case to get access
701 to the circuit board.
704 Plug the 8-pin end of the programming cable to the matching
705 connector on the TeleDongle, and the 4-pins into the holes
706 in the TeleMini circuit board. Note that the MicroMaTch
707 connector has an alignment pin that goes through a hole in
708 the PC board when you have the cable oriented correctly, and
709 that pin 1 on the TeleMini board is marked with a square pad
710 while the other pins have round pads.
713 Attach a battery to the TeleMini board.
716 Plug the TeleDongle into your computer's USB port, and power
720 Run AltosUI, and select 'Flash Image' from the File menu.
723 Pick the TeleDongle device from the list, identifying it as the
727 Select the image you want put on the TeleMini, which should have a
728 name in the form telemini-v1.0-1.0.0.ihx. It should be visible
729 in the default directory, if not you may have to poke around
730 your system to find it.
733 Make sure the configuration parameters are reasonable
734 looking. If the serial number and/or RF configuration
735 values aren't right, you'll need to change them.
738 Hit the 'OK' button and the software should proceed to flash
739 the TeleMini with new firmware, showing a progress bar.
742 Confirm that the TeleMini board seems to have updated OK, which you
743 can do by configuring it over the RF link through the TeleDongle, or
744 letting it come up in "flight" mode and listening for telemetry.
747 If something goes wrong, give it another try.
752 <title>Updating TeleDongle Firmware</title>
754 Updating TeleDongle's firmware is just like updating TeleMetrum or TeleMini
755 firmware, but you use either a TeleMetrum or another TeleDongle as the programmer.
757 <orderedlist inheritnum='inherit' numeration='arabic'>
759 Find the 'programming cable' that you got as part of the starter
760 kit, that has a red 8-pin MicroMaTch connector on one end and a
761 red 4-pin MicroMaTch connector on the other end.
764 Find the USB cable that you got as part of the starter kit, and
765 plug the "mini" end in to the mating connector on TeleMetrum or TeleDongle.
768 Take the 2 screws out of the TeleDongle case to get access
769 to the circuit board.
772 Plug the 8-pin end of the programming cable to the
773 matching connector on the programmer, and the 4-pin end to the
774 matching connector on the TeleDongle.
775 Note that each MicroMaTch connector has an alignment pin that
776 goes through a hole in the PC board when you have the cable
780 Attach a battery to the TeleMetrum board if you're using one.
783 Plug both the programmer and the TeleDongle into your computer's USB
784 ports, and power up the programmer.
787 Run AltosUI, and select 'Flash Image' from the File menu.
790 Pick the programmer device from the list, identifying it as the
794 Select the image you want put on the TeleDongle, which should have a
795 name in the form teledongle-v0.2-1.0.0.ihx. It should be visible
796 in the default directory, if not you may have to poke around
797 your system to find it.
800 Make sure the configuration parameters are reasonable
801 looking. If the serial number and/or RF configuration
802 values aren't right, you'll need to change them. The TeleDongle
803 serial number is on the "bottom" of the circuit board, and can
804 usually be read through the translucent blue plastic case without
805 needing to remove the board from the case.
808 Hit the 'OK' button and the software should proceed to flash
809 the TeleDongle with new firmware, showing a progress bar.
812 Confirm that the TeleDongle board seems to have updated OK, which you
813 can do by plugging in to it over USB and using a terminal program
814 to connect to the board and issue the 'v' command to check
815 the version, etc. Once you're happy, remove the programming cable
816 and put the cover back on the TeleDongle.
819 If something goes wrong, give it another try.
823 Be careful removing the programming cable from the locking 8-pin
824 connector on TeleMetrum. You'll need a fingernail or perhaps a thin
825 screwdriver or knife blade to gently pry the locking ears out
826 slightly to extract the connector. We used a locking connector on
827 TeleMetrum to help ensure that the cabling to companion boards
828 used in a rocket don't ever come loose accidentally in flight.
836 <title>AltosUI</title>
838 The AltosUI program provides a graphical user interface for
839 interacting with the Altus Metrum product family, including
840 TeleMetrum, TeleMini and TeleDongle. AltosUI can monitor telemetry data,
841 configure TeleMetrum, TeleMini and TeleDongle devices and many other
842 tasks. The primary interface window provides a selection of
843 buttons, one for each major activity in the system. This manual
844 is split into chapters, each of which documents one of the tasks
845 provided from the top-level toolbar.
848 <title>Monitor Flight</title>
849 <subtitle>Receive, Record and Display Telemetry Data</subtitle>
851 Selecting this item brings up a dialog box listing all of the
852 connected TeleDongle devices. When you choose one of these,
853 AltosUI will create a window to display telemetry data as
854 received by the selected TeleDongle device.
857 All telemetry data received are automatically recorded in
858 suitable log files. The name of the files includes the current
859 date and rocket serial and flight numbers.
862 The radio frequency being monitored by the TeleDongle device is
863 displayed at the top of the window. You can configure the
864 frequency by clicking on the frequency box and selecting the desired
865 frequency. AltosUI remembers the last frequency selected for each
866 TeleDongle and selects that automatically the next time you use
870 Below the TeleDongle frequency selector, the window contains a few
871 significant pieces of information about the altimeter providing
872 the telemetry data stream:
876 <para>The configured call-sign</para>
879 <para>The device serial number</para>
882 <para>The flight number. Each altimeter remembers how many
888 The rocket flight state. Each flight passes through several
889 states including Pad, Boost, Fast, Coast, Drogue, Main and
895 The Received Signal Strength Indicator value. This lets
896 you know how strong a signal TeleDongle is receiving. The
897 radio inside TeleDongle operates down to about -99dBm;
898 weaker signals may not be receivable. The packet link uses
899 error correction and detection techniques which prevent
900 incorrect data from being reported.
905 Finally, the largest portion of the window contains a set of
906 tabs, each of which contain some information about the rocket.
907 They're arranged in 'flight order' so that as the flight
908 progresses, the selected tab automatically switches to display
909 data relevant to the current state of the flight. You can select
910 other tabs at any time. The final 'table' tab contains all of
911 the telemetry data in one place.
914 <title>Launch Pad</title>
916 The 'Launch Pad' tab shows information used to decide when the
917 rocket is ready for flight. The first elements include red/green
918 indicators, if any of these is red, you'll want to evaluate
919 whether the rocket is ready to launch:
923 Battery Voltage. This indicates whether the Li-Po battery
924 powering the TeleMetrum has sufficient charge to last for
925 the duration of the flight. A value of more than
926 3.7V is required for a 'GO' status.
931 Apogee Igniter Voltage. This indicates whether the apogee
932 igniter has continuity. If the igniter has a low
933 resistance, then the voltage measured here will be close
934 to the Li-Po battery voltage. A value greater than 3.2V is
935 required for a 'GO' status.
940 Main Igniter Voltage. This indicates whether the main
941 igniter has continuity. If the igniter has a low
942 resistance, then the voltage measured here will be close
943 to the Li-Po battery voltage. A value greater than 3.2V is
944 required for a 'GO' status.
949 On-board Data Logging. This indicates whether there is
950 space remaining on-board to store flight data for the
951 upcoming flight. If you've downloaded data, but failed
952 to erase flights, there may not be any space
953 left. TeleMetrum can store multiple flights, depending
954 on the configured maximum flight log size. TeleMini
955 stores only a single flight, so it will need to be
956 downloaded and erased after each flight to capture
957 data. This only affects on-board flight logging; the
958 altimeter will still transmit telemetry and fire
959 ejection charges at the proper times.
964 GPS Locked. For a TeleMetrum device, this indicates whether the GPS receiver is
965 currently able to compute position information. GPS requires
966 at least 4 satellites to compute an accurate position.
971 GPS Ready. For a TeleMetrum device, this indicates whether GPS has reported at least
972 10 consecutive positions without losing lock. This ensures
973 that the GPS receiver has reliable reception from the
979 The Launchpad tab also shows the computed launch pad position
980 and altitude, averaging many reported positions to improve the
986 <title>Ascent</title>
988 This tab is shown during Boost, Fast and Coast
989 phases. The information displayed here helps monitor the
990 rocket as it heads towards apogee.
993 The height, speed and acceleration are shown along with the
994 maximum values for each of them. This allows you to quickly
995 answer the most commonly asked questions you'll hear during
999 The current latitude and longitude reported by the TeleMetrum GPS are
1000 also shown. Note that under high acceleration, these values
1001 may not get updated as the GPS receiver loses position
1002 fix. Once the rocket starts coasting, the receiver should
1003 start reporting position again.
1006 Finally, the current igniter voltages are reported as in the
1007 Launch Pad tab. This can help diagnose deployment failures
1008 caused by wiring which comes loose under high acceleration.
1012 <title>Descent</title>
1014 Once the rocket has reached apogee and (we hope) activated the
1015 apogee charge, attention switches to tracking the rocket on
1016 the way back to the ground, and for dual-deploy flights,
1017 waiting for the main charge to fire.
1020 To monitor whether the apogee charge operated correctly, the
1021 current descent rate is reported along with the current
1022 height. Good descent rates generally range from 15-30m/s.
1025 For TeleMetrum altimeters, you can locate the rocket in the sky
1026 using the elevation and
1027 bearing information to figure out where to look. Elevation is
1028 in degrees above the horizon. Bearing is reported in degrees
1029 relative to true north. Range can help figure out how big the
1030 rocket will appear. Note that all of these values are relative
1031 to the pad location. If the elevation is near 90°, the rocket
1032 is over the pad, not over you.
1035 Finally, the igniter voltages are reported in this tab as
1036 well, both to monitor the main charge as well as to see what
1037 the status of the apogee charge is.
1041 <title>Landed</title>
1043 Once the rocket is on the ground, attention switches to
1044 recovery. While the radio signal is generally lost once the
1045 rocket is on the ground, the last reported GPS position is
1046 generally within a short distance of the actual landing location.
1049 The last reported GPS position is reported both by
1050 latitude and longitude as well as a bearing and distance from
1051 the launch pad. The distance should give you a good idea of
1052 whether you'll want to walk or hitch a ride. Take the reported
1053 latitude and longitude and enter them into your hand-held GPS
1054 unit and have that compute a track to the landing location.
1057 Both TeleMini and TeleMetrum will continue to transmit RDF
1058 tones after landing, allowing you to locate the rocket by
1059 following the radio signal. You may need to get away from
1060 the clutter of the flight line, or even get up on a hill (or
1061 your neighbor's RV) to receive the RDF signal.
1064 The maximum height, speed and acceleration reported
1065 during the flight are displayed for your admiring observers.
1068 To get more detailed information about the flight, you can
1069 click on the 'Graph Flight' button which will bring up a
1070 graph window for the current flight.
1074 <title>Site Map</title>
1076 When the TeleMetrum gets a GPS fix, the Site Map tab will map
1077 the rocket's position to make it easier for you to locate the
1078 rocket, both while it is in the air, and when it has landed. The
1079 rocket's state is indicated by color: white for pad, red for
1080 boost, pink for fast, yellow for coast, light blue for drogue,
1081 dark blue for main, and black for landed.
1084 The map's scale is approximately 3m (10ft) per pixel. The map
1085 can be dragged using the left mouse button. The map will attempt
1086 to keep the rocket roughly centered while data is being received.
1089 Images are fetched automatically via the Google Maps Static API,
1090 and are cached for reuse. If map images cannot be downloaded,
1091 the rocket's path will be traced on a dark gray background
1095 You can pre-load images for your favorite launch sites
1096 before you leave home; check out the 'Preload Maps' section below.
1101 <title>Packet Command Mode</title>
1102 <subtitle>Controlling An Altimeter Over The Radio Link</subtitle>
1104 One of the unique features of the Altus Metrum environment is
1105 the ability to create a two way command link between TeleDongle
1106 and an altimeter using the digital radio transceivers built into
1107 each device. This allows you to interact with the altimeter from
1108 afar, as if it were directly connected to the computer.
1111 Any operation which can be performed with TeleMetrum
1112 can either be done with TeleMetrum directly connected to
1113 the computer via the USB cable, or through the packet
1114 link. Simply select the appropriate TeleDongle device when
1115 the list of devices is presented and AltosUI will use packet
1119 One oddity in the current interface is how AltosUI selects the
1120 frequency for packet mode communications. Instead of providing
1121 an interface to specifically configure the frequency, it uses
1122 whatever frequency was most recently selected for the target
1123 TeleDongle device in Monitor Flight mode. If you haven't ever
1124 used that mode with the TeleDongle in question, select the
1125 Monitor Flight button from the top level UI, pick the
1126 appropriate TeleDongle device. Once the flight monitoring
1127 window is open, select the desired frequency and then close it
1128 down again. All Packet Command Mode operations will now use
1134 Save Flight Data—Recover flight data from the rocket without
1140 Configure altimeter apogee delays or main deploy heights
1141 to respond to changing launch conditions. You can also
1142 'reboot' the altimeter. Use this to remotely enable the
1143 flight computer by turning TeleMetrum on in "idle" mode,
1144 then once the air-frame is oriented for launch, you can
1145 reboot the altimeter and have it restart in pad mode
1146 without having to climb the scary ladder.
1151 Fire Igniters—Test your deployment charges without snaking
1152 wires out through holes in the air-frame. Simply assembly the
1153 rocket as if for flight with the apogee and main charges
1154 loaded, then remotely command the altimeter to fire the
1160 Packet command mode uses the same RF frequencies as telemetry
1161 mode. Configure the desired TeleDongle frequency using the
1162 flight monitor window frequency selector and then close that
1163 window before performing the desired operation.
1166 TeleMetrum only enables packet command mode in 'idle' mode, so
1167 make sure you have TeleMetrum lying horizontally when you turn
1168 it on. Otherwise, TeleMetrum will start in 'pad' mode ready for
1169 flight and will not be listening for command packets from TeleDongle.
1172 TeleMini listens for a command packet for five seconds after
1173 first being turned on, if it doesn't hear anything, it enters
1174 'pad' mode, ready for flight and will no longer listen for
1178 When packet command mode is enabled, you can monitor the link
1179 by watching the lights on the
1180 devices. The red LED will flash each time they
1181 transmit a packet while the green LED will light up
1182 on TeleDongle while it is waiting to receive a packet from
1187 <title>Save Flight Data</title>
1189 The altimeter records flight data to its internal flash memory.
1190 The TeleMetrum data is recorded at a much higher rate than the telemetry
1191 system can handle, and is not subject to radio drop-outs. As
1192 such, it provides a more complete and precise record of the
1193 flight. The 'Save Flight Data' button allows you to read the
1194 flash memory and write it to disk. As TeleMini has only a barometer, it
1195 records data at the same rate as the telemetry signal, but there will be
1196 no data lost due to telemetry drop-outs.
1199 Clicking on the 'Save Flight Data' button brings up a list of
1200 connected TeleMetrum and TeleDongle devices. If you select a
1201 TeleMetrum device, the flight data will be downloaded from that
1202 device directly. If you select a TeleDongle device, flight data
1203 will be downloaded from a TeleMetrum or TeleMini device connected via the
1204 packet command link to the specified TeleDongle. See the chapter
1205 on Packet Command Mode for more information about this.
1208 After the device has been selected, a dialog showing the
1209 flight data saved in the device will be shown allowing you to
1210 select which flights to download and which to delete. With
1211 version 0.9 or newer firmware, you must erase flights in order
1212 for the space they consume to be reused by another
1213 flight. This prevents you from accidentally losing flight data
1214 if you neglect to download data before flying again. Note that
1215 if there is no more space available in the device, then no
1216 data will be recorded for a flight.
1219 The file name for each flight log is computed automatically
1220 from the recorded flight date, altimeter serial number and
1221 flight number information.
1225 <title>Replay Flight</title>
1227 Select this button and you are prompted to select a flight
1228 record file, either a .telem file recording telemetry data or a
1229 .eeprom file containing flight data saved from the altimeter
1233 Once a flight record is selected, the flight monitor interface
1234 is displayed and the flight is re-enacted in real time. Check
1235 the Monitor Flight chapter above to learn how this window operates.
1239 <title>Graph Data</title>
1241 Select this button and you are prompted to select a flight
1242 record file, either a .telem file recording telemetry data or a
1243 .eeprom file containing flight data saved from
1247 Once a flight record is selected, a window with two tabs is
1248 opened. The first tab contains a graph with acceleration
1249 (blue), velocity (green) and altitude (red) of the flight are
1250 plotted and displayed, measured in metric units. The
1251 apogee(yellow) and main(magenta) igniter voltages are also
1252 displayed; high voltages indicate continuity, low voltages
1253 indicate open circuits. The second tab contains some basic
1257 The graph can be zoomed into a particular area by clicking and
1258 dragging down and to the right. Once zoomed, the graph can be
1259 reset by clicking and dragging up and to the left. Holding down
1260 control and clicking and dragging allows the graph to be panned.
1261 The right mouse button causes a pop-up menu to be displayed, giving
1262 you the option save or print the plot.
1265 Note that telemetry files will generally produce poor graphs
1266 due to the lower sampling rate and missed telemetry packets.
1267 Use saved flight data for graphing where possible.
1271 <title>Export Data</title>
1273 This tool takes the raw data files and makes them available for
1274 external analysis. When you select this button, you are prompted to select a flight
1275 data file (either .eeprom or .telem will do, remember that
1276 .eeprom files contain higher resolution and more continuous
1277 data). Next, a second dialog appears which is used to select
1278 where to write the resulting file. It has a selector to choose
1279 between CSV and KML file formats.
1282 <title>Comma Separated Value Format</title>
1284 This is a text file containing the data in a form suitable for
1285 import into a spreadsheet or other external data analysis
1286 tool. The first few lines of the file contain the version and
1287 configuration information from the altimeter, then
1288 there is a single header line which labels all of the
1289 fields. All of these lines start with a '#' character which
1290 most tools can be configured to skip over.
1293 The remaining lines of the file contain the data, with each
1294 field separated by a comma and at least one space. All of
1295 the sensor values are converted to standard units, with the
1296 barometric data reported in both pressure, altitude and
1297 height above pad units.
1301 <title>Keyhole Markup Language (for Google Earth)</title>
1303 This is the format used by
1304 Googleearth to provide an overlay within that
1305 application. With this, you can use Googleearth to see the
1306 whole flight path in 3D.
1311 <title>Configure Altimeter</title>
1313 Select this button and then select either a TeleMetrum or
1314 TeleDongle Device from the list provided. Selecting a TeleDongle
1315 device will use Packet Command Mode to configure a remote
1316 altimeter. Learn how to use this in the Packet Command
1320 The first few lines of the dialog provide information about the
1321 connected device, including the product name,
1322 software version and hardware serial number. Below that are the
1323 individual configuration entries.
1326 At the bottom of the dialog, there are four buttons:
1331 Save. This writes any changes to the
1332 configuration parameter block in flash memory. If you don't
1333 press this button, any changes you make will be lost.
1338 Reset. This resets the dialog to the most recently saved values,
1339 erasing any changes you have made.
1344 Reboot. This reboots the device. Use this to
1345 switch from idle to pad mode by rebooting once the rocket is
1346 oriented for flight.
1351 Close. This closes the dialog. Any unsaved changes will be
1357 The rest of the dialog contains the parameters to be configured.
1360 <title>Main Deploy Altitude</title>
1362 This sets the altitude (above the recorded pad altitude) at
1363 which the 'main' igniter will fire. The drop-down menu shows
1364 some common values, but you can edit the text directly and
1365 choose whatever you like. If the apogee charge fires below
1366 this altitude, then the main charge will fire two seconds
1367 after the apogee charge fires.
1371 <title>Apogee Delay</title>
1373 When flying redundant electronics, it's often important to
1374 ensure that multiple apogee charges don't fire at precisely
1375 the same time as that can over pressurize the apogee deployment
1376 bay and cause a structural failure of the air-frame. The Apogee
1377 Delay parameter tells the flight computer to fire the apogee
1378 charge a certain number of seconds after apogee has been
1383 <title>Radio Frequency</title>
1385 This configures which of the configured frequencies to use for both
1386 telemetry and packet command mode. Note that if you set this
1387 value via packet command mode, you will have to reconfigure
1388 the TeleDongle frequency before you will be able to use packet
1393 <title>Radio Calibration</title>
1395 The radios in every Altus Metrum device are calibrated at the
1396 factory to ensure that they transmit and receive on the
1397 specified frequency. You can adjust that
1398 calibration by changing this value. To change the TeleDongle's
1399 calibration, you must reprogram the unit completely.
1403 <title>Callsign</title>
1405 This sets the call sign included in each telemetry packet. Set this
1406 as needed to conform to your local radio regulations.
1410 <title>Maximum Flight Log Size</title>
1412 This sets the space (in kilobytes) allocated for each flight
1413 log. The available space will be divided into chunks of this
1414 size. A smaller value will allow more flights to be stored,
1415 a larger value will record data from longer flights.
1418 During ascent, TeleMetrum records barometer and
1419 accelerometer values 100 times per second, other analog
1420 information (voltages and temperature) 6 times per second
1421 and GPS data once per second. During descent, the non-GPS
1422 data is recorded 1/10th as often. Each barometer +
1423 accelerometer record takes 8 bytes.
1426 The default, 192kB, will store over 200 seconds of data at
1427 the ascent rate, or over 2000 seconds of data at the descent
1428 rate. That's plenty for most flights. This leaves enough
1429 storage for five flights in a 1MB system, or 10 flights in a
1433 The configuration block takes the last available block of
1434 memory, on v1.0 boards that's just 256 bytes. However, the
1435 flash part on the v1.1 boards uses 64kB for each block.
1438 TeleMini has 5kB of on-board storage, which is plenty for a
1439 single flight. Make sure you download and delete the data
1440 before a subsequent flight or it will not log any data.
1444 <title>Ignite Mode</title>
1446 TeleMetrum and TeleMini provide two igniter channels as they
1447 were originally designed as dual-deploy flight
1448 computers. This configuration parameter allows the two
1449 channels to be used in different configurations.
1454 Dual Deploy. This is the usual mode of operation; the
1455 'apogee' channel is fired at apogee and the 'main'
1456 channel at the height above ground specified by the
1457 'Main Deploy Altitude' during descent.
1462 Redundant Apogee. This fires both channels at
1463 apogee, the 'apogee' channel first followed after a two second
1464 delay by the 'main' channel.
1469 Redundant Main. This fires both channels at the
1470 height above ground specified by the Main Deploy
1471 Altitude setting during descent. The 'apogee'
1472 channel is fired first, followed after a two second
1473 delay by the 'main' channel.
1479 <title>Pad Orientation</title>
1481 Because it includes an accelerometer, TeleMetrum is
1482 sensitive to the orientation of the board. By default, it
1483 expects the antenna end to point forward. This parameter
1484 allows that default to be changed, permitting the board to
1485 be mounted with the antenna pointing aft instead.
1490 Antenna Up. In this mode, the antenna end of the
1491 TeleMetrum board must point forward, in line with the
1492 expected flight path.
1497 Antenna Down. In this mode, the antenna end of the
1498 TeleMetrum board must point aft, in line with the
1499 expected flight path.
1506 <title>Configure AltosUI</title>
1508 This button presents a dialog so that you can configure the AltosUI global settings.
1511 <title>Voice Settings</title>
1513 AltosUI provides voice announcements during flight so that you
1514 can keep your eyes on the sky and still get information about
1515 the current flight status. However, sometimes you don't want
1520 <para>Enable—turns all voice announcements on and off</para>
1524 Test Voice—Plays a short message allowing you to verify
1525 that the audio system is working and the volume settings
1532 <title>Log Directory</title>
1534 AltosUI logs all telemetry data and saves all TeleMetrum flash
1535 data to this directory. This directory is also used as the
1536 staring point when selecting data files for display or export.
1539 Click on the directory name to bring up a directory choosing
1540 dialog, select a new directory and click 'Select Directory' to
1541 change where AltosUI reads and writes data files.
1545 <title>Callsign</title>
1547 This value is used in command packet mode and is transmitted
1548 in each packet sent from TeleDongle and received from
1549 TeleMetrum. It is not used in telemetry mode as that transmits
1550 packets only from TeleMetrum to TeleDongle. Configure this
1551 with the AltosUI operators call sign as needed to comply with
1552 your local radio regulations.
1556 <title>Font Size</title>
1558 Selects the set of fonts used in the flight monitor
1559 window. Choose between the small, medium and large sets.
1563 <title>Serial Debug</title>
1565 This causes all communication with a connected device to be
1566 dumped to the console from which AltosUI was started. If
1567 you've started it from an icon or menu entry, the output
1568 will simply be discarded. This mode can be useful to debug
1569 various serial communication issues.
1573 <title>Manage Frequencies</title>
1575 This brings up a dialog where you can configure the set of
1576 frequencies shown in the various frequency menus. You can
1577 add as many as you like, or even reconfigure the default
1578 set. Changing this list does not affect the frequency
1579 settings of any devices, it only changes the set of
1580 frequencies shown in the menus.
1585 <title>Flash Image</title>
1587 This reprograms any Altus Metrum device by using a TeleMetrum
1588 or TeleDongle as a programming dongle. Please read the
1589 directions for flashing devices in the Updating Device
1590 Firmware section above
1593 Once you have the programmer and target devices connected,
1594 push the 'Flash Image' button. That will present a dialog box
1595 listing all of the connected devices. Carefully select the
1596 programmer device, not the device to be programmed.
1599 Next, select the image to flash to the device. These are named
1600 with the product name and firmware version. The file selector
1601 will start in the directory containing the firmware included
1602 with the AltosUI package. Navigate to the directory containing
1603 the desired firmware if it isn't there.
1606 Next, a small dialog containing the device serial number and
1607 RF calibration values should appear. If these values are
1608 incorrect (possibly due to a corrupted image in the device),
1609 enter the correct values here.
1612 Finally, a dialog containing a progress bar will follow the
1613 programming process.
1616 When programming is complete, the target device will
1617 reboot. Note that if the target device is connected via USB, you
1618 will have to unplug it and then plug it back in for the USB
1619 connection to reset so that you can communicate with the device
1624 <title>Fire Igniter</title>
1626 This activates the igniter circuits in TeleMetrum to help test
1627 recovery systems deployment. Because this command can operate
1628 over the Packet Command Link, you can prepare the rocket as
1629 for flight and then test the recovery system without needing
1630 to snake wires inside the air-frame.
1633 Selecting the 'Fire Igniter' button brings up the usual device
1634 selection dialog. Pick the desired TeleDongle or TeleMetrum
1635 device. This brings up another window which shows the current
1636 continuity test status for both apogee and main charges.
1639 Next, select the desired igniter to fire. This will enable the
1643 Select the 'Arm' button. This enables the 'Fire' button. The
1644 word 'Arm' is replaced by a countdown timer indicating that
1645 you have 10 seconds to press the 'Fire' button or the system
1646 will deactivate, at which point you start over again at
1647 selecting the desired igniter.
1651 <title>Scan Channels</title>
1653 This listens for telemetry packets on all of the configured
1654 frequencies, displaying information about each device it
1655 receives a packet from. You can select which of the three
1656 telemetry formats should be tried; by default, it only listens
1657 for the standard telemetry packets used in v1.0 and later
1662 <title>Load Maps</title>
1664 Before heading out to a new launch site, you can use this to
1665 load satellite images in case you don't have internet
1666 connectivity at the site. This loads a fairly large area
1667 around the launch site, which should cover any flight you're likely to make.
1670 There's a drop-down menu of launch sites we know about; if
1671 your favorites aren't there, please let us know the lat/lon
1672 and name of the site. The contents of this list are actually
1673 downloaded at run-time, so as new sites are sent in, they'll
1674 get automatically added to this list.
1677 If the launch site isn't in the list, you can manually enter the lat/lon values
1680 Clicking the 'Load Map' button will fetch images from Google
1681 Maps; note that Google limits how many images you can fetch at
1682 once, so if you load more than one launch site, you may get
1683 some gray areas in the map which indicate that Google is tired
1684 of sending data to you. Try again later.
1688 <title>Monitor Idle</title>
1690 This brings up a dialog similar to the Monitor Flight UI,
1691 except it works with the altimeter in "idle" mode by sending
1692 query commands to discover the current state rather than
1693 listening for telemetry packets.
1698 <title>Using Altus Metrum Products</title>
1700 <title>Being Legal</title>
1702 First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
1703 other authorization to legally operate the radio transmitters that are part
1708 <title>In the Rocket</title>
1710 In the rocket itself, you just need a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> or
1711 <ulink url="http://www.altusmetrum.org/TeleMini/">TeleMini</ulink> board and
1712 a Li-Po rechargeable battery. An 860mAh battery weighs less than a 9V
1713 alkaline battery, and will run a TeleMetrum for hours.
1714 A 110mAh battery weighs less than a triple A battery and will run a TeleMetrum for
1715 a few hours, or a TeleMini for much (much) longer.
1718 By default, we ship the altimeters with a simple wire antenna. If your
1719 electronics bay or the air-frame it resides within is made of carbon fiber,
1720 which is opaque to RF signals, you may choose to have an SMA connector
1721 installed so that you can run a coaxial cable to an antenna mounted
1722 elsewhere in the rocket.
1726 <title>On the Ground</title>
1728 To receive the data stream from the rocket, you need an antenna and short
1729 feed-line connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> units. The
1730 TeleDongle in turn plugs directly into the USB port on a notebook
1731 computer. Because TeleDongle looks like a simple serial port, your computer
1732 does not require special device drivers... just plug it in.
1735 The GUI tool, AltosUI, is written in Java and runs across
1736 Linux, Mac OS and Windows. There's also a suite of C tools
1737 for Linux which can perform most of the same tasks.
1740 After the flight, you can use the RF link to extract the more detailed data
1741 logged in either TeleMetrum or TeleMini devices, or you can use a mini USB cable to plug into the
1742 TeleMetrum board directly. Pulling out the data without having to open up
1743 the rocket is pretty cool! A USB cable is also how you charge the Li-Po
1744 battery, so you'll want one of those anyway... the same cable used by lots
1745 of digital cameras and other modern electronic stuff will work fine.
1748 If your TeleMetrum-equipped rocket lands out of sight, you may enjoy having a hand-held GPS
1749 receiver, so that you can put in a way-point for the last reported rocket
1750 position before touch-down. This makes looking for your rocket a lot like
1751 Geo-Caching... just go to the way-point and look around starting from there.
1754 You may also enjoy having a ham radio "HT" that covers the 70cm band... you
1755 can use that with your antenna to direction-find the rocket on the ground
1756 the same way you can use a Walston or Beeline tracker. This can be handy
1757 if the rocket is hiding in sage brush or a tree, or if the last GPS position
1758 doesn't get you close enough because the rocket dropped into a canyon, or
1759 the wind is blowing it across a dry lake bed, or something like that... Keith
1760 and Bdale both currently own and use the Yaesu VX-7R at launches.
1763 So, to recap, on the ground the hardware you'll need includes:
1764 <orderedlist inheritnum='inherit' numeration='arabic'>
1766 an antenna and feed-line
1775 optionally, a hand-held GPS receiver
1778 optionally, an HT or receiver covering 435 MHz
1783 The best hand-held commercial directional antennas we've found for radio
1784 direction finding rockets are from
1785 <ulink url="http://www.arrowantennas.com/" >
1788 The 440-3 and 440-5 are both good choices for finding a
1789 TeleMetrum- or TeleMini- equipped rocket when used with a suitable 70cm HT.
1793 <title>Data Analysis</title>
1795 Our software makes it easy to log the data from each flight, both the
1796 telemetry received over the RF link during the flight itself, and the more
1797 complete data log recorded in the flash memory on the altimeter
1798 board. Once this data is on your computer, our post-flight tools make it
1799 easy to quickly get to the numbers everyone wants, like apogee altitude,
1800 max acceleration, and max velocity. You can also generate and view a
1801 standard set of plots showing the altitude, acceleration, and
1802 velocity of the rocket during flight. And you can even export a TeleMetrum data file
1803 usable with Google Maps and Google Earth for visualizing the flight path
1804 in two or three dimensions!
1807 Our ultimate goal is to emit a set of files for each flight that can be
1808 published as a web page per flight, or just viewed on your local disk with
1813 <title>Future Plans</title>
1815 In the future, we intend to offer "companion boards" for the rocket that will
1816 plug in to TeleMetrum to collect additional data, provide more pyro channels,
1817 and so forth. A reference design for a companion board will be documented
1818 soon, and will be compatible with open source Arduino programming tools.
1821 We are also working on the design of a hand-held ground terminal that will
1822 allow monitoring the rocket's status, collecting data during flight, and
1823 logging data after flight without the need for a notebook computer on the
1824 flight line. Particularly since it is so difficult to read most notebook
1825 screens in direct sunlight, we think this will be a great thing to have.
1828 Because all of our work is open, both the hardware designs and the software,
1829 if you have some great idea for an addition to the current Altus Metrum family,
1830 feel free to dive in and help! Or let us know what you'd like to see that
1831 we aren't already working on, and maybe we'll get excited about it too...
1836 <title>Altimeter Installation Recommendations</title>
1838 Building high-power rockets that fly safely is hard enough. Mix
1839 in some sophisticated electronics and a bunch of radio energy
1840 and oftentimes you find few perfect solutions. This chapter
1841 contains some suggestions about how to install Altus Metrum
1842 products into the rocket air-frame, including how to safely and
1843 reliably mix a variety of electronics into the same air-frame.
1846 <title>Mounting the Altimeter</title>
1848 The first consideration is to ensure that the altimeter is
1849 securely fastened to the air-frame. For TeleMetrum, we use
1850 nylon standoffs and nylon screws; they're good to at least 50G
1851 and cannot cause any electrical issues on the board. For
1852 TeleMini, we usually cut small pieces of 1/16" balsa to fit
1853 under the screw holes, and then take 2x56 nylon screws and
1854 screw them through the TeleMini mounting holes, through the
1855 balsa and into the underlying material.
1857 <orderedlist inheritnum='inherit' numeration='arabic'>
1859 Make sure TeleMetrum is aligned precisely along the axis of
1860 acceleration so that the accelerometer can accurately
1861 capture data during the flight.
1864 Watch for any metal touching components on the
1865 board. Shorting out connections on the bottom of the board
1866 can cause the altimeter to fail during flight.
1871 <title>Dealing with the Antenna</title>
1873 The antenna supplied is just a piece of solid, insulated,
1874 wire. If it gets damaged or broken, it can be easily
1875 replaced. It should be kept straight and not cut; bending or
1876 cutting it will change the resonant frequency and/or
1877 impedance, making it a less efficient radiator and thus
1878 reducing the range of the telemetry signal.
1881 Keeping metal away from the antenna will provide better range
1882 and a more even radiation pattern. In most rockets, it's not
1883 entirely possible to isolate the antenna from metal
1884 components; there are often bolts, all-thread and wires from other
1885 electronics to contend with. Just be aware that the more stuff
1886 like this around the antenna, the lower the range.
1889 Make sure the antenna is not inside a tube made or covered
1890 with conducting material. Carbon fiber is the most common
1891 culprit here -- CF is a good conductor and will effectively
1892 shield the antenna, dramatically reducing signal strength and
1893 range. Metallic flake paint is another effective shielding
1894 material which is to be avoided around any antennas.
1897 If the ebay is large enough, it can be convenient to simply
1898 mount the altimeter at one end and stretch the antenna out
1899 inside. Taping the antenna to the sled can keep it straight
1900 under acceleration. If there are metal rods, keep the
1901 antenna as far away as possible.
1904 For a shorter ebay, it's quite practical to have the antenna
1905 run through a bulkhead and into an adjacent bay. Drill a small
1906 hole in the bulkhead, pass the antenna wire through it and
1907 then seal it up with glue or clay. We've also used acrylic
1908 tubing to create a cavity for the antenna wire. This works a
1909 bit better in that the antenna is known to stay straight and
1910 not get folded by recovery components in the bay. Angle the
1911 tubing towards the side wall of the rocket and it ends up
1912 consuming very little space.
1915 If you need to place the antenna at a distance from the
1916 altimeter, you can replace the antenna with an edge-mounted
1917 SMA connector, and then run 50Ω coax from the board to the
1918 antenna. Building a remote antenna is beyond the scope of this
1923 <title>Preserving GPS Reception</title>
1925 The GPS antenna and receiver in TeleMetrum are highly
1926 sensitive and normally have no trouble tracking enough
1927 satellites to provide accurate position information for
1928 recovering the rocket. However, there are many ways to
1929 attenuate the GPS signal.
1930 <orderedlist inheritnum='inherit' numeration='arabic'>
1932 Conductive tubing or coatings. Carbon fiber and metal
1933 tubing, or metallic paint will all dramatically attenuate the
1934 GPS signal. We've never heard of anyone successfully
1935 receiving GPS from inside these materials.
1938 Metal components near the GPS patch antenna. These will
1939 de-tune the patch antenna, changing the resonant frequency
1940 away from the L1 carrier and reduce the effectiveness of the
1941 antenna. You can place as much stuff as you like beneath the
1942 antenna as that's covered with a ground plane. But, keep
1943 wires and metal out from above the patch antenna.
1949 <title>Radio Frequency Interference</title>
1951 Any altimeter will generate RFI; the digital circuits use
1952 high-frequency clocks that spray radio interference across a
1953 wide band. Altusmetrum altimeters generate intentional radio
1954 signals as well, increasing the amount of RF energy around the board.
1957 Rocketry altimeters also use precise sensors measuring air
1958 pressure and acceleration. Tiny changes in voltage can cause
1959 these sensor readings to vary by a huge amount. When the
1960 sensors start mis-reporting data, the altimeter can either
1961 fire the igniters at the wrong time, or not fire them at all.
1964 Voltages are induced when radio frequency energy is
1965 transmitted from one circuit to another. Here are things that
1966 increase the induced voltage and current:
1970 Keep wires from different circuits apart. Moving circuits
1971 further apart will reduce RFI.
1974 Avoid parallel wires from different circuits. The longer two
1975 wires run parallel to one another, the larger the amount of
1976 transferred energy. Cross wires at right angles to reduce
1980 Twist wires from the same circuits. Two wires the same
1981 distance from the transmitter will get the same amount of
1982 induced energy which will then cancel out. Any time you have
1983 a wire pair running together, twist the pair together to
1984 even out distances and reduce RFI. For altimeters, this
1985 includes battery leads, switch hookups and igniter
1989 Avoid resonant lengths. Know what frequencies are present
1990 in the environment and avoid having wire lengths near a
1991 natural resonant length. Altusmetrum products transmit on the
1992 70cm amateur band, so you should avoid lengths that are a
1993 simple ratio of that length; essentially any multiple of 1/4
1994 of the wavelength (17.5cm).
1999 <title>The Barometric Sensor</title>
2001 Altusmetrum altimeters measure altitude with a barometric
2002 sensor, essentially measuring the amount of air above the
2003 rocket to figure out how high it is. A large number of
2004 measurements are taken as the altimeter initializes itself to
2005 figure out the pad altitude. Subsequent measurements are then
2006 used to compute the height above the pad.
2009 To accurately measure atmospheric pressure, the ebay
2010 containing the altimeter must be vented outside the
2011 air-frame. The vent must be placed in a region of linear
2012 airflow, smooth and not in an area of increasing or decreasing
2016 The barometric sensor in the altimeter is quite sensitive to
2017 chemical damage from the products of APCP or BP combustion, so
2018 make sure the ebay is carefully sealed from any compartment
2019 which contains ejection charges or motors.
2023 <title>Ground Testing</title>
2025 The most important aspect of any installation is careful
2026 ground testing. Bringing an air-frame up to the LCO table which
2027 hasn't been ground tested can lead to delays or ejection
2028 charges firing on the pad, or, even worse, a recovery system
2032 Do a 'full systems' test that includes wiring up all igniters
2033 without any BP and turning on all of the electronics in flight
2034 mode. This will catch any mistakes in wiring and any residual
2035 RFI issues that might accidentally fire igniters at the wrong
2036 time. Let the air-frame sit for several minutes, checking for
2037 adequate telemetry signal strength and GPS lock.
2040 Ground test the ejection charges. Prepare the rocket for
2041 flight, loading ejection charges and igniters. Completely
2042 assemble the air-frame and then use the 'Fire Igniters'
2043 interface through a TeleDongle to command each charge to
2044 fire. Make sure the charge is sufficient to robustly separate
2045 the air-frame and deploy the recovery system.
2050 <title>Hardware Specifications</title>
2052 <title>TeleMetrum Specifications</title>
2056 Recording altimeter for model rocketry.
2061 Supports dual deployment (can fire 2 ejection charges).
2066 70cm ham-band transceiver for telemetry down-link.
2071 Barometric pressure sensor good to 45k feet MSL.
2076 1-axis high-g accelerometer for motor characterization, capable of
2077 +/- 50g using default part.
2082 On-board, integrated GPS receiver with 5Hz update rate capability.
2087 On-board 1 megabyte non-volatile memory for flight data storage.
2092 USB interface for battery charging, configuration, and data recovery.
2097 Fully integrated support for Li-Po rechargeable batteries.
2102 Uses Li-Po to fire e-matches, can be modified to support
2103 optional separate pyro battery if needed.
2108 2.75 x 1 inch board designed to fit inside 29mm air-frame coupler tube.
2114 <title>TeleMini Specifications</title>
2118 Recording altimeter for model rocketry.
2123 Supports dual deployment (can fire 2 ejection charges).
2128 70cm ham-band transceiver for telemetry down-link.
2133 Barometric pressure sensor good to 45k feet MSL.
2138 On-board 5 kilobyte non-volatile memory for flight data storage.
2143 RF interface for battery charging, configuration, and data recovery.
2148 Support for Li-Po rechargeable batteries, using an external charger.
2153 Uses Li-Po to fire e-matches, can be modified to support
2154 optional separate pyro battery if needed.
2159 1.5 x .5 inch board designed to fit inside 18mm air-frame coupler tube.
2168 TeleMetrum seems to shut off when disconnected from the
2169 computer. Make sure the battery is adequately charged. Remember the
2170 unit will pull more power than the USB port can deliver before the
2171 GPS enters "locked" mode. The battery charges best when TeleMetrum
2175 It's impossible to stop the TeleDongle when it's in "p" mode, I have
2176 to unplug the USB cable? Make sure you have tried to "escape out" of
2177 this mode. If this doesn't work the reboot procedure for the
2178 TeleDongle *is* to simply unplug it. 'cu' however will retain it's
2179 outgoing buffer IF your "escape out" ('~~') does not work.
2180 At this point using either 'ao-view' (or possibly
2181 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
2185 The amber LED (on the TeleMetrum) lights up when both
2186 battery and USB are connected. Does this mean it's charging?
2187 Yes, the yellow LED indicates the charging at the 'regular' rate.
2188 If the led is out but the unit is still plugged into a USB port,
2189 then the battery is being charged at a 'trickle' rate.
2192 There are no "dit-dah-dah-dit" sound or lights like the manual mentions?
2193 That's the "pad" mode. Weak batteries might be the problem.
2194 It is also possible that the TeleMetrum is horizontal and the output
2195 is instead a "dit-dit" meaning 'idle'. For TeleMini, it's possible that
2196 it received a command packet which would have left it in "pad" mode.
2199 How do I save flight data?
2200 Live telemetry is written to file(s) whenever AltosUI is connected
2201 to the TeleDongle. The file area defaults to ~/TeleMetrum
2202 but is easily changed using the menus in AltosUI. The files that
2203 are written end in '.telem'. The after-flight
2204 data-dumped files will end in .eeprom and represent continuous data
2205 unlike the RF-linked .telem files that are subject to losses
2206 along the RF data path.
2207 See the above instructions on what and how to save the eeprom stored
2208 data after physically retrieving your altimeter. Make sure to save
2209 the on-board data after each flight; while the TeleMetrum can store
2210 multiple flights, you never know when you'll lose the altimeter...
2214 <title>Notes for Older Software</title>
2217 Before AltosUI was written, using Altus Metrum devices required
2218 some finesse with the Linux command line. There was a limited
2219 GUI tool, ao-view, which provided functionality similar to the
2220 Monitor Flight window in AltosUI, but everything else was a
2221 fairly 80's experience. This appendix includes documentation for
2222 using that software.
2226 Both TeleMetrum and TeleDongle can be directly communicated
2227 with using USB ports. The first thing you should try after getting
2228 both units plugged into to your computer's USB port(s) is to run
2229 'ao-list' from a terminal-window to see what port-device-name each
2230 device has been assigned by the operating system.
2231 You will need this information to access the devices via their
2232 respective on-board firmware and data using other command line
2233 programs in the AltOS software suite.
2236 TeleMini can be communicated with through a TeleDongle device
2237 over the radio link. When first booted, TeleMini listens for a
2238 TeleDongle device and if it receives a packet, it goes into
2239 'idle' mode. Otherwise, it goes into 'pad' mode and waits to be
2240 launched. The easiest way to get it talking is to start the
2241 communication link on the TeleDongle and the power up the
2245 To access the device's firmware for configuration you need a terminal
2246 program such as you would use to talk to a modem. The software
2247 authors prefer using the program 'cu' which comes from the UUCP package
2248 on most Unix-like systems such as Linux. An example command line for
2249 cu might be 'cu -l /dev/ttyACM0', substituting the correct number
2250 indicated from running the
2251 ao-list program. Another reasonable terminal program for Linux is
2252 'cutecom'. The default 'escape'
2253 character used by CU (i.e. the character you use to
2254 issue commands to cu itself instead of sending the command as input
2255 to the connected device) is a '~'. You will need this for use in
2256 only two different ways during normal operations. First is to exit
2257 the program by sending a '~.' which is called a 'escape-disconnect'
2258 and allows you to close-out from 'cu'. The
2259 second use will be outlined later.
2262 All of the Altus Metrum devices share the concept of a two level
2263 command set in their firmware.
2264 The first layer has several single letter commands. Once
2265 you are using 'cu' (or 'cutecom') sending (typing) a '?'
2266 returns a full list of these
2267 commands. The second level are configuration sub-commands accessed
2268 using the 'c' command, for
2269 instance typing 'c?' will give you this second level of commands
2270 (all of which require the
2271 letter 'c' to access). Please note that most configuration options
2272 are stored only in Flash memory; TeleDongle doesn't provide any storage
2273 for these options and so they'll all be lost when you unplug it.
2276 Try setting these configuration ('c' or second level menu) values. A good
2277 place to start is by setting your call sign. By default, the boards
2278 use 'N0CALL' which is cute, but not exactly legal!
2279 Spend a few minutes getting comfortable with the units, their
2280 firmware, and 'cu' (or possibly 'cutecom').
2281 For instance, try to send
2282 (type) a 'c r 2' and verify the channel change by sending a 'c s'.
2283 Verify you can connect and disconnect from the units while in your
2284 terminal program by sending the escape-disconnect mentioned above.
2287 Note that the 'reboot' command, which is very useful on the altimeters,
2288 will likely just cause problems with the dongle. The *correct* way
2289 to reset the dongle is just to unplug and re-plug it.
2292 A fun thing to do at the launch site and something you can do while
2293 learning how to use these units is to play with the RF-link access
2294 between an altimeter and the TeleDongle. Be aware that you *must* create
2295 some physical separation between the devices, otherwise the link will
2296 not function due to signal overload in the receivers in each device.
2299 Now might be a good time to take a break and read the rest of this
2300 manual, particularly about the two "modes" that the altimeters
2301 can be placed in. TeleMetrum uses the position of the device when booting
2302 up will determine whether the unit is in "pad" or "idle" mode. TeleMini
2303 enters "idle" mode when it receives a command packet within the first 5 seconds
2304 of being powered up, otherwise it enters "pad" mode.
2307 You can access an altimeter in idle mode from the TeleDongle's USB
2308 connection using the RF link
2309 by issuing a 'p' command to the TeleDongle. Practice connecting and
2310 disconnecting ('~~' while using 'cu') from the altimeter. If
2311 you cannot escape out of the "p" command, (by using a '~~' when in
2312 CU) then it is likely that your kernel has issues. Try a newer version.
2315 Using this RF link allows you to configure the altimeter, test
2316 fire e-matches and igniters from the flight line, check pyro-match
2317 continuity and so forth. You can leave the unit turned on while it
2318 is in 'idle mode' and then place the
2319 rocket vertically on the launch pad, walk away and then issue a
2320 reboot command. The altimeter will reboot and start sending data
2321 having changed to the "pad" mode. If the TeleDongle is not receiving
2322 this data, you can disconnect 'cu' from the TeleDongle using the
2323 procedures mentioned above and THEN connect to the TeleDongle from
2324 inside 'ao-view'. If this doesn't work, disconnect from the
2325 TeleDongle, unplug it, and try again after plugging it back in.
2328 In order to reduce the chance of accidental firing of pyrotechnic
2329 charges, the command to fire a charge is intentionally somewhat
2330 difficult to type, and the built-in help is slightly cryptic to
2331 prevent accidental echoing of characters from the help text back at
2332 the board from firing a charge. The command to fire the apogee
2333 drogue charge is 'i DoIt drogue' and the command to fire the main
2334 charge is 'i DoIt main'.
2337 On TeleMetrum, the GPS will eventually find enough satellites, lock in on them,
2338 and 'ao-view' will both auditorily announce and visually indicate
2340 Now you can launch knowing that you have a good data path and
2341 good satellite lock for flight data and recovery. Remember
2342 you MUST tell ao-view to connect to the TeleDongle explicitly in
2343 order for ao-view to be able to receive data.
2346 The altimeters provide RDF (radio direction finding) tones on
2347 the pad, during descent and after landing. These can be used to
2348 locate the rocket using a directional antenna; the signal
2349 strength providing an indication of the direction from receiver to rocket.
2352 TeleMetrum also provides GPS trekking data, which can further simplify
2353 locating the rocket once it has landed. (The last good GPS data
2354 received before touch-down will be on the data screen of 'ao-view'.)
2357 Once you have recovered the rocket you can download the eeprom
2358 contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over
2359 either a USB cable or over the radio link using TeleDongle.
2360 And by following the man page for 'ao-postflight' you can create
2361 various data output reports, graphs, and even KML data to see the
2362 flight trajectory in Google-earth. (Moving the viewing angle making
2363 sure to connect the yellow lines while in Google-earth is the proper
2367 As for ao-view.... some things are in the menu but don't do anything
2368 very useful. The developers have stopped working on ao-view to focus
2369 on a new, cross-platform ground station program. So ao-view may or
2370 may not be updated in the future. Mostly you just use
2371 the Log and Device menus. It has a wonderful display of the incoming
2372 flight data and I am sure you will enjoy what it has to say to you
2373 once you enable the voice output!
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