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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>10 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 (TeleMetrum/TeleMini and
44 TeleDongle) must be updated or communications will fail.
48 <revnumber>0.9</revnumber>
49 <date>18 January 2011</date>
51 Updated for software version 0.9. Note that 0.9 represents a
52 telemetry format change, meaning both ends of a link (TeleMetrum and
53 TeleDongle) must be updated or communications will fail.
57 <revnumber>0.8</revnumber>
58 <date>24 November 2010</date>
59 <revremark>Updated for software version 0.8 </revremark>
65 Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing "The
66 Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter
67 Kit" which has turned into the Getting Started chapter in this
68 book. Bob was one of our first customers for a production
69 TeleMetrum, and the enthusiasm that led to his contribution of
70 this section is immensely gratifying and highly appreciated!
73 And thanks to Anthony (AJ) Towns for contributing the
74 AltosUI graphing and site map code and documentation. Free
75 software means that our customers and friends can become our
76 collaborators, and we certainly appreciate this level of
80 Have fun using these products, and we hope to meet all of you
81 out on the rocket flight line somewhere.
84 NAR #87103, TRA #12201
87 NAR #88757, TRA #12200
92 <title>Introduction and Overview</title>
94 Welcome to the Altus Metrum community! Our circuits and software reflect
95 our passion for both hobby rocketry and Free Software. We hope their
96 capabilities and performance will delight you in every way, but by
97 releasing all of our hardware and software designs under open licenses,
98 we also hope to empower you to take as active a role in our collective
102 The first device created for our community was TeleMetrum, a dual
103 deploy altimeter with fully integrated GPS and radio telemetry
104 as standard features, and a "companion interface" that will
105 support optional capabilities in the future.
108 The newest device is TeleMini, a dual deploy altimeter with
109 radio telemetry and radio direction finding. This device is only
110 13mm by 38mm (½ inch by 1½ inches) and can fit easily in an 18mm air-frame.
113 Complementing TeleMetrum and TeleMini is TeleDongle, a USB to RF interface for
114 communicating with the altimeters. Combined with your choice of antenna and
115 notebook computer, TeleDongle and our associated user interface software
116 form a complete ground station capable of logging and displaying in-flight
117 telemetry, aiding rocket recovery, then processing and archiving flight
118 data for analysis and review.
121 More products will be added to the Altus Metrum family over time, and
122 we currently envision that this will be a single, comprehensive manual
123 for the entire product family.
127 <title>Getting Started</title>
129 The first thing to do after you check the inventory of parts in your
130 "starter kit" is to charge the battery.
133 The TeleMetrum battery can be charged by plugging it into the
134 corresponding socket of the TeleMetrum and then using the USB A to
136 cable to plug the TeleMetrum into your computer's USB socket. The
137 TeleMetrum circuitry will charge the battery whenever it is plugged
138 in, because the TeleMetrum's on-off switch does NOT control the
142 When the GPS chip is initially searching for
143 satellites, TeleMetrum will consume more current than it can pull
144 from the USB port, so the battery must be attached in order to get
145 satellite lock. Once GPS is locked, the current consumption goes back
146 down enough to enable charging while
147 running. So it's a good idea to fully charge the battery as your
148 first item of business so there is no issue getting and maintaining
149 satellite lock. The yellow charge indicator led will go out when the
150 battery is nearly full and the charger goes to trickle charge. It
151 can take several hours to fully recharge a deeply discharged battery.
154 The TeleMini battery can be charged by disconnecting it from the
155 TeleMini board and plugging it into a standalone battery charger
156 board, and connecting that via a USB cable to a laptop or other USB
160 The other active device in the starter kit is the TeleDongle USB to
161 RF interface. If you plug it in to your Mac or Linux computer it should
162 "just work", showing up as a serial port device. Windows systems need
163 driver information that is part of the AltOS download to know that the
164 existing USB modem driver will work. We therefore recommend installing
165 our software before plugging in TeleDongle if you are using a Windows
166 computer. If you are using Linux and are having problems, try moving
167 to a fresher kernel (2.6.33 or newer), as the USB serial driver had
168 ugly bugs in some earlier versions.
171 Next you should obtain and install the AltOS utilities. These include
172 the AltosUI ground station program, current firmware images for
173 TeleMetrum, TeleMini and TeleDongle, and a number of standalone utilities that
174 are rarely needed. Pre-built binary packages are available for Debian
175 Linux, Microsoft Windows, and recent MacOSX versions. Full source code
176 and build instructions for some other Linux variants are also available.
177 The latest version may always be downloaded from
178 <ulink url="http://altusmetrum.org/AltOS"/>.
182 <title>Handling Precautions</title>
184 All Altus Metrum products are sophisticated electronic devices.
185 When handled gently and properly installed in an air-frame, they
186 will deliver impressive results. However, like all electronic
187 devices, there are some precautions you must take.
190 The Lithium Polymer rechargeable batteries have an
191 extraordinary power density. This is great because we can fly with
192 much less battery mass than if we used alkaline batteries or previous
193 generation rechargeable batteries... but if they are punctured
194 or their leads are allowed to short, they can and will release their
196 Thus we recommend that you take some care when handling our batteries
197 and consider giving them some extra protection in your air-frame. We
198 often wrap them in suitable scraps of closed-cell packing foam before
199 strapping them down, for example.
202 The barometric sensors used on both TeleMetrum and TeleMini are
203 sensitive to sunlight. In normal TeleMetrum mounting situations, it
204 and all of the other surface mount components
205 are "down" towards whatever the underlying mounting surface is, so
206 this is not normally a problem. Please consider this, though, when
207 designing an installation, for example, in an air-frame with a
208 see-through plastic payload bay. It is particularly important to
209 consider this with TeleMini, both because the baro sensor is on the
210 "top" of the board, and because many model rockets with payload bays
211 use clear plastic for the payload bay! Replacing these with an opaque
212 cardboard tube, painting them, or wrapping them with a layer of masking
213 tape are all reasonable approaches to keep the sensor out of direct
217 The barometric sensor sampling port must be able to "breathe",
218 both by not being covered by foam or tape or other materials that might
219 directly block the hole on the top of the sensor, and also by having a
220 suitable static vent to outside air.
223 As with all other rocketry electronics, Altus Metrum altimeters must
224 be protected from exposure to corrosive motor exhaust and ejection
229 <title>Hardware Overview</title>
231 TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to
232 fit inside coupler for 29mm air-frame tubing, but using it in a tube that
233 small in diameter may require some creativity in mounting and wiring
234 to succeed! The presence of an accelerometer means TeleMetrum should
235 be aligned along the flight axis of the airframe, and by default the 1/4
236 wave UHF wire antenna should be on the nose-cone end of the board. The
237 antenna wire is about 7 inches long, and wiring for a power switch and
238 the e-matches for apogee and main ejection charges depart from the
239 fin can end of the board, meaning an ideal "simple" avionics
240 bay for TeleMetrum should have at least 10 inches of interior length.
243 TeleMini is a 0.5 inch by 1.5 inch circuit board. It was designed to
244 fit inside an 18mm air-frame tube, but using it in a tube that
245 small in diameter may require some creativity in mounting and wiring
246 to succeed! Since there is no accelerometer, TeleMini can be mounted
247 in any convenient orientation. The default 1/4
248 wave UHF wire antenna attached to the center of one end of
249 the board is about 7 inches long, and wiring for a power switch and
250 the e-matches for apogee and main ejection charges depart from the
251 other end of the board, meaning an ideal "simple" avionics
252 bay for TeleMini should have at least 9 inches of interior length.
255 A typical TeleMetrum or TeleMini installation involves attaching
256 only a suitable Lithium Polymer battery, a single pole switch for
257 power on/off, and two pairs of wires connecting e-matches for the
258 apogee and main ejection charges.
261 By default, we use the unregulated output of the Li-Po battery directly
262 to fire ejection charges. This works marvelously with standard
263 low-current e-matches like the J-Tek from MJG Technologies, and with
264 Quest Q2G2 igniters. However, if you want or need to use a separate
265 pyro battery, check out the "External Pyro Battery" section in this
266 manual for instructions on how to wire that up. The altimeters are
267 designed to work with an external pyro battery of no more than 15 volts.
270 Ejection charges are wired directly to the screw terminal block
271 at the aft end of the altimeter. You'll need a very small straight
272 blade screwdriver for these screws, such as you might find in a
273 jeweler's screwdriver set.
276 TeleMetrum also uses the screw terminal block for the power
277 switch leads. On TeleMini, the power switch leads are soldered
278 directly to the board and can be connected directly to a switch.
281 For most air-frames, the integrated antennas are more than
282 adequate. However, if you are installing in a carbon-fiber or
283 metal electronics bay which is opaque to RF signals, you may need to
284 use off-board external antennas instead. In this case, you can
285 order an altimeter with an SMA connector for the UHF antenna
286 connection, and, on TeleMetrum, you can unplug the integrated GPS
287 antenna and select an appropriate off-board GPS antenna with
288 cable terminating in a U.FL connector.
292 <title>System Operation</title>
294 <title>Firmware Modes </title>
296 The AltOS firmware build for the altimeters has two
297 fundamental modes, "idle" and "flight". Which of these modes
298 the firmware operates in is determined at start up time. For
299 TeleMetrum, the mode is controlled by the orientation of the
300 rocket (well, actually the board, of course...) at the time
301 power is switched on. If the rocket is "nose up", then
302 TeleMetrum assumes it's on a rail or rod being prepared for
303 launch, so the firmware chooses flight mode. However, if the
304 rocket is more or less horizontal, the firmware instead enters
305 idle mode. Since TeleMini doesn't have an accelerometer we can
306 use to determine orientation, "idle" mode is selected when the
307 board receives a command packet within the first five seconds
308 of operation; if no packet is received, the board enters
312 At power on, you will hear three beeps or see three flashes
313 ("S" in Morse code for start up) and then a pause while
314 the altimeter completes initialization and self test, and decides
315 which mode to enter next.
318 In flight or "pad" mode, the altimeter engages the flight
319 state machine, goes into transmit-only mode on the RF link
320 sending telemetry, and waits for launch to be detected.
321 Flight mode is indicated by an "di-dah-dah-dit" ("P" for pad)
322 on the beeper or lights, followed by beeps or flashes
323 indicating the state of the pyrotechnic igniter continuity.
324 One beep/flash indicates apogee continuity, two beeps/flashes
325 indicate main continuity, three beeps/flashes indicate both
326 apogee and main continuity, and one longer "brap" sound or
327 rapidly alternating lights indicates no continuity. For a
328 dual deploy flight, make sure you're getting three beeps or
329 flashes before launching! For apogee-only or motor eject
330 flights, do what makes sense.
333 If idle mode is entered, you will hear an audible "di-dit" or see
334 two short flashes ("I" for idle), and the flight state machine is
335 disengaged, thus no ejection charges will fire. The altimeters also
336 listen on the RF link when in idle mode for requests sent via
337 TeleDongle. Commands can be issued to a TeleMetrum in idle mode
339 USB or the RF link equivalently. TeleMini only has the RF link.
340 Idle mode is useful for configuring the altimeter, for extracting data
341 from the on-board storage chip after flight, and for ground testing
345 One "neat trick" of particular value when TeleMetrum is used with
346 very large air-frames, is that you can power the board up while the
347 rocket is horizontal, such that it comes up in idle mode. Then you can
348 raise the air-frame to launch position, and issue a 'reset' command
349 via TeleDongle over the RF link to cause the altimeter to reboot and
350 come up in flight mode. This is much safer than standing on the top
351 step of a rickety step-ladder or hanging off the side of a launch
352 tower with a screw-driver trying to turn on your avionics before
359 TeleMetrum includes a complete GPS receiver. A complete explanation
360 of how GPS works is beyond the scope of this manual, but the bottom
361 line is that the TeleMetrum GPS receiver needs to lock onto at least
362 four satellites to obtain a solid 3 dimensional position fix and know
366 TeleMetrum provides backup power to the GPS chip any time a
367 battery is connected. This allows the receiver to "warm start" on
368 the launch rail much faster than if every power-on were a GPS
369 "cold start". In typical operations, powering up TeleMetrum
370 on the flight line in idle mode while performing final air-frame
371 preparation will be sufficient to allow the GPS receiver to cold
372 start and acquire lock. Then the board can be powered down during
373 RSO review and installation on a launch rod or rail. When the board
374 is turned back on, the GPS system should lock very quickly, typically
375 long before igniter installation and return to the flight line are
380 <title>Ground Testing </title>
382 An important aspect of preparing a rocket using electronic deployment
383 for flight is ground testing the recovery system. Thanks
384 to the bi-directional RF link central to the Altus Metrum system,
385 this can be accomplished in a TeleMetrum or TeleMini equipped rocket
386 with less work than you may be accustomed to with other systems. It
390 Just prep the rocket for flight, then power up the altimeter
391 in "idle" mode (placing air-frame horizontal for TeleMetrum or
392 selected the Configure Altimeter tab for TeleMini). This will cause
393 the firmware to go into "idle" mode, in which the normal flight
394 state machine is disabled and charges will not fire without
395 manual command. You can now command the altimeter to fire the apogee
396 or main charges from a safe distance using your computer and
397 TeleDongle and the Fire Igniter tab to complete ejection testing.
401 <title>Radio Link </title>
403 The chip our boards are based on incorporates an RF transceiver, but
404 it's not a full duplex system... each end can only be transmitting or
405 receiving at any given moment. So we had to decide how to manage the
409 By design, the altimeter firmware listens for an RF connection when
410 it's in "idle mode", which
411 allows us to use the RF link to configure the rocket, do things like
412 ejection tests, and extract data after a flight without having to
413 crack open the air-frame. However, when the board is in "flight
414 mode", the altimeter only
415 transmits and doesn't listen at all. That's because we want to put
416 ultimate priority on event detection and getting telemetry out of
417 the rocket and out over
418 the RF link in case the rocket crashes and we aren't able to extract
422 We don't use a 'normal packet radio' mode because they're just too
423 inefficient. The GFSK modulation we use is just FSK with the
424 base-band pulses passed through a
425 Gaussian filter before they go into the modulator to limit the
426 transmitted bandwidth. When combined with the hardware forward error
427 correction support in the cc1111 chip, this allows us to have a very
428 robust 38.4 kilobit data link with only 10 milliwatts of transmit power,
429 a whip antenna in the rocket, and a hand-held Yagi on the ground. We've
430 had flights to above 21k feet AGL with good reception, and calculations
431 suggest we should be good to well over 40k feet AGL with a 5-element yagi on
432 the ground. We hope to fly boards to higher altitudes soon, and would
433 of course appreciate customer feedback on performance in higher
438 <title>Configurable Parameters</title>
440 Configuring an Altus Metrum altimeter for flight is very
441 simple. Through the use of a Kalman filter, there is no need
442 to set a "mach delay" . The few configurable parameters can
443 all be set using a simple terminal program over the USB port
444 or RF link via TeleDongle.
447 <title>Radio Frequencies</title>
449 The Altus Metrum boards support frequencies in the 70cm
450 band. By default, the configuration interface provides a
451 list of 10 common frequencies -- 100kHz channels starting at
452 434.550MHz. However, you can configure the firmware to use
453 any 50kHz multiple within the 70cm band. At any given
454 launch, we highly recommend coordinating who will use each
455 frequency and when to avoid interference. And of course, both
456 altimeter and TeleDongle must be configured to the same
457 frequency to successfully communicate with each other.
460 To set the radio frequency, use the 'c R' command to specify the
461 radio transceiver configuration parameter. This parameter is computed
462 using the desired frequency, 'F', the radio calibration parameter, 'C' (showed by the 'c s' command) and
463 the standard calibration reference frequency, 'S', (normally 434.550MHz):
467 Round the result to the nearest integer value.
468 As with all 'c' sub-commands, follow this with a 'c w' to write the
469 change to the parameter block in the on-board flash on
470 your altimeter board if you want the change to stay in place across reboots.
474 <title>Apogee Delay</title>
476 Apogee delay is the number of seconds after the altimeter detects flight
477 apogee that the drogue charge should be fired. In most cases, this
478 should be left at the default of 0. However, if you are flying
479 redundant electronics such as for an L3 certification, you may wish
480 to set one of your altimeters to a positive delay so that both
481 primary and backup pyrotechnic charges do not fire simultaneously.
484 To set the apogee delay, use the 'c d' command.
485 As with all 'c' sub-commands, follow this with a 'c w' to write the
486 change to the parameter block in the on-board DataFlash chip.
489 Please note that the Altus Metrum apogee detection algorithm
490 fires exactly at apogee. If you are also flying an
491 altimeter like the PerfectFlite MAWD, which only supports
492 selecting 0 or 1 seconds of apogee delay, you may wish to
493 set the MAWD to 0 seconds delay and set the TeleMetrum to
494 fire your backup 2 or 3 seconds later to avoid any chance of
495 both charges firing simultaneously. We've flown several
496 air-frames this way quite happily, including Keith's
501 <title>Main Deployment Altitude</title>
503 By default, the altimeter will fire the main deployment charge at an
504 elevation of 250 meters (about 820 feet) above ground. We think this
505 is a good elevation for most air-frames, but feel free to change this
506 to suit. In particular, if you are flying two altimeters, you may
508 deployment elevation for the backup altimeter to be something lower
509 than the primary so that both pyrotechnic charges don't fire
513 To set the main deployment altitude, use the 'c m' command.
514 As with all 'c' sub-commands, follow this with a 'c w' to write the
515 change to the parameter block in the on-board DataFlash chip.
520 <title>Calibration</title>
522 There are only two calibrations required for a TeleMetrum board, and
523 only one for TeleDongle and TeleMini.
526 <title>Radio Frequency</title>
528 The radio frequency is synthesized from a clock based on the 48 MHz
529 crystal on the board. The actual frequency of this oscillator must be
530 measured to generate a calibration constant. While our GFSK modulation
531 bandwidth is wide enough to allow boards to communicate even when
532 their oscillators are not on exactly the same frequency, performance
533 is best when they are closely matched.
534 Radio frequency calibration requires a calibrated frequency counter.
535 Fortunately, once set, the variation in frequency due to aging and
536 temperature changes is small enough that re-calibration by customers
537 should generally not be required.
540 To calibrate the radio frequency, connect the UHF antenna port to a
541 frequency counter, set the board to 434.550MHz, and use the 'C'
542 command to generate a CW carrier. Wait for the transmitter temperature
543 to stabilize and the frequency to settle down.
544 Then, divide 434.550 MHz by the
545 measured frequency and multiply by the current radio cal value show
546 in the 'c s' command. For an unprogrammed board, the default value
547 is 1186611. Take the resulting integer and program it using the 'c f'
548 command. Testing with the 'C' command again should show a carrier
549 within a few tens of Hertz of the intended frequency.
550 As with all 'c' sub-commands, follow this with a 'c w' to write the
551 change to the parameter block in the on-board DataFlash chip.
554 when the radio calibration value is changed, the radio
555 frequency value is reset to the same value, so you'll need
556 to recompute and reset the radio frequency value using the
557 new radio calibration value.
561 <title>TeleMetrum Accelerometer</title>
563 The TeleMetrum accelerometer we use has its own 5 volt power supply and
564 the output must be passed through a resistive voltage divider to match
565 the input of our 3.3 volt ADC. This means that unlike the barometric
566 sensor, the output of the acceleration sensor is not ratio-metric to
567 the ADC converter, and calibration is required. We also support the
568 use of any of several accelerometers from a Freescale family that
569 includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity,
570 a simple 2-point calibration yields acceptable results capturing both
571 the different sensitivities and ranges of the different accelerometer
572 parts and any variation in power supply voltages or resistor values
573 in the divider network.
576 To calibrate the acceleration sensor, use the 'c a 0' command. You
577 will be prompted to orient the board vertically with the UHF antenna
578 up and press a key, then to orient the board vertically with the
579 UHF antenna down and press a key.
580 As with all 'c' sub-commands, follow this with a 'c w' to write the
581 change to the parameter block in the on-board DataFlash chip.
584 The +1g and -1g calibration points are included in each telemetry
585 frame and are part of the header extracted by ao-dumplog after flight.
586 Note that we always store and return raw ADC samples for each
587 sensor... nothing is permanently "lost" or "damaged" if the
591 In the unlikely event an accel cal that goes badly, it is possible
592 that TeleMetrum may always come up in 'pad mode' and as such not be
593 listening to either the USB or radio interfaces. If that happens,
594 there is a special hook in the firmware to force the board back
595 in to 'idle mode' so you can re-do the cal. To use this hook, you
596 just need to ground the SPI clock pin at power-on. This pin is
597 available as pin 2 on the 8-pin companion connector, and pin 1 is
598 ground. So either carefully install a fine-gauge wire jumper
599 between the two pins closest to the index hole end of the 8-pin
600 connector, or plug in the programming cable to the 8-pin connector
601 and use a small screwdriver or similar to short the two pins closest
602 to the index post on the 4-pin end of the programming cable, and
603 power up the board. It should come up in 'idle mode' (two beeps).
608 <title>Updating Device Firmware</title>
610 The big conceptual thing to realize is that you have to use a
611 TeleDongle as a programmer to update a TeleMetrum or TeleMini,
612 and a TeleMetrum or other TeleDongle to program the TeleDongle
613 Due to limited memory resources in the cc1111, we don't support
614 programming directly over USB.
617 You may wish to begin by ensuring you have current firmware images.
618 These are distributed as part of the AltOS software bundle that
619 also includes the AltosUI ground station program. Newer ground
620 station versions typically work fine with older firmware versions,
621 so you don't need to update your devices just to try out new
622 software features. You can always download the most recent
623 version from <ulink url="http://www.altusmetrum.org/AltOS/"/>.
626 We recommend updating the altimeter first, before updating TeleDongle.
629 <title>Updating TeleMetrum Firmware</title>
630 <orderedlist inheritnum='inherit' numeration='arabic'>
632 Find the 'programming cable' that you got as part of the starter
633 kit, that has a red 8-pin MicroMaTch connector on one end and a
634 red 4-pin MicroMaTch connector on the other end.
637 Take the 2 screws out of the TeleDongle case to get access
638 to the circuit board.
641 Plug the 8-pin end of the programming cable to the
642 matching connector on the TeleDongle, and the 4-pin end to the
643 matching connector on the TeleMetrum.
644 Note that each MicroMaTch connector has an alignment pin that
645 goes through a hole in the PC board when you have the cable
649 Attach a battery to the TeleMetrum board.
652 Plug the TeleDongle into your computer's USB port, and power
656 Run AltosUI, and select 'Flash Image' from the File menu.
659 Pick the TeleDongle device from the list, identifying it as the
663 Select the image you want put on the TeleMetrum, which should have a
664 name in the form telemetrum-v1.1-1.0.0.ihx. It should be visible
665 in the default directory, if not you may have to poke around
666 your system to find it.
669 Make sure the configuration parameters are reasonable
670 looking. If the serial number and/or RF configuration
671 values aren't right, you'll need to change them.
674 Hit the 'OK' button and the software should proceed to flash
675 the TeleMetrum with new firmware, showing a progress bar.
678 Confirm that the TeleMetrum board seems to have updated OK, which you
679 can do by plugging in to it over USB and using a terminal program
680 to connect to the board and issue the 'v' command to check
684 If something goes wrong, give it another try.
689 <title>Updating TeleMini Firmware</title>
690 <orderedlist inheritnum='inherit' numeration='arabic'>
692 You'll need a special 'programming cable' to reprogram the
693 TeleMini. It's available on the Altus Metrum web store, or
694 you can make your own using an 8-pin MicroMaTch connector on
695 one end and a set of four pins on the other.
698 Take the 2 screws out of the TeleDongle case to get access
699 to the circuit board.
702 Plug the 8-pin end of the programming cable to the matching
703 connector on the TeleDongle, and the 4-pins into the holes
704 in the TeleMini circuit board. Note that the MicroMaTch
705 connector has an alignment pin that goes through a hole in
706 the PC board when you have the cable oriented correctly, and
707 that pin 1 on the TeleMini board is marked with a square pad
708 while the other pins have round pads.
711 Attach a battery to the TeleMini board.
714 Plug the TeleDongle into your computer's USB port, and power
718 Run AltosUI, and select 'Flash Image' from the File menu.
721 Pick the TeleDongle device from the list, identifying it as the
725 Select the image you want put on the TeleMini, which should have a
726 name in the form telemini-v1.0-1.0.0.ihx. It should be visible
727 in the default directory, if not you may have to poke around
728 your system to find it.
731 Make sure the configuration parameters are reasonable
732 looking. If the serial number and/or RF configuration
733 values aren't right, you'll need to change them.
736 Hit the 'OK' button and the software should proceed to flash
737 the TeleMini with new firmware, showing a progress bar.
740 Confirm that the TeleMini board seems to have updated OK, which you
741 can do by configuring it over the RF link through the TeleDongle, or
742 letting it come up in "flight" mode and listening for telemetry.
745 If something goes wrong, give it another try.
750 <title>Updating TeleDongle Firmware</title>
752 Updating TeleDongle's firmware is just like updating TeleMetrum or TeleMini
753 firmware, but you use either a TeleMetrum or another TeleDongle as the programmer.
755 <orderedlist inheritnum='inherit' numeration='arabic'>
757 Find the 'programming cable' that you got as part of the starter
758 kit, that has a red 8-pin MicroMaTch connector on one end and a
759 red 4-pin MicroMaTch connector on the other end.
762 Find the USB cable that you got as part of the starter kit, and
763 plug the "mini" end in to the mating connector on TeleMetrum or TeleDongle.
766 Take the 2 screws out of the TeleDongle case to get access
767 to the circuit board.
770 Plug the 8-pin end of the programming cable to the
771 matching connector on the programmer, and the 4-pin end to the
772 matching connector on the TeleDongle.
773 Note that each MicroMaTch connector has an alignment pin that
774 goes through a hole in the PC board when you have the cable
778 Attach a battery to the TeleMetrum board if you're using one.
781 Plug both the programmer and the TeleDongle into your computer's USB
782 ports, and power up the programmer.
785 Run AltosUI, and select 'Flash Image' from the File menu.
788 Pick the programmer device from the list, identifying it as the
792 Select the image you want put on the TeleDongle, which should have a
793 name in the form teledongle-v0.2-1.0.0.ihx. It should be visible
794 in the default directory, if not you may have to poke around
795 your system to find it.
798 Make sure the configuration parameters are reasonable
799 looking. If the serial number and/or RF configuration
800 values aren't right, you'll need to change them. The TeleDongle
801 serial number is on the "bottom" of the circuit board, and can
802 usually be read through the translucent blue plastic case without
803 needing to remove the board from the case.
806 Hit the 'OK' button and the software should proceed to flash
807 the TeleDongle with new firmware, showing a progress bar.
810 Confirm that the TeleDongle board seems to have updated OK, which you
811 can do by plugging in to it over USB and using a terminal program
812 to connect to the board and issue the 'v' command to check
813 the version, etc. Once you're happy, remove the programming cable
814 and put the cover back on the TeleDongle.
817 If something goes wrong, give it another try.
821 Be careful removing the programming cable from the locking 8-pin
822 connector on TeleMetrum. You'll need a fingernail or perhaps a thin
823 screwdriver or knife blade to gently pry the locking ears out
824 slightly to extract the connector. We used a locking connector on
825 TeleMetrum to help ensure that the cabling to companion boards
826 used in a rocket don't ever come loose accidentally in flight.
834 <title>AltosUI</title>
836 The AltosUI program provides a graphical user interface for
837 interacting with the Altus Metrum product family, including
838 TeleMetrum, TeleMini and TeleDongle. AltosUI can monitor telemetry data,
839 configure TeleMetrum, TeleMini and TeleDongle devices and many other
840 tasks. The primary interface window provides a selection of
841 buttons, one for each major activity in the system. This manual
842 is split into chapters, each of which documents one of the tasks
843 provided from the top-level toolbar.
846 <title>Monitor Flight</title>
847 <subtitle>Receive, Record and Display Telemetry Data</subtitle>
849 Selecting this item brings up a dialog box listing all of the
850 connected TeleDongle devices. When you choose one of these,
851 AltosUI will create a window to display telemetry data as
852 received by the selected TeleDongle device.
855 All telemetry data received are automatically recorded in
856 suitable log files. The name of the files includes the current
857 date and rocket serial and flight numbers.
860 The radio frequency being monitored by the TeleDongle device is
861 displayed at the top of the window. You can configure the
862 frequency by clicking on the frequency box and selecting the desired
863 frequency. AltosUI remembers the last frequency selected for each
864 TeleDongle and selects that automatically the next time you use
868 Below the TeleDongle frequency selector, the window contains a few
869 significant pieces of information about the altimeter providing
870 the telemetry data stream:
874 <para>The configured call-sign</para>
877 <para>The device serial number</para>
880 <para>The flight number. Each altimeter remembers how many
886 The rocket flight state. Each flight passes through several
887 states including Pad, Boost, Fast, Coast, Drogue, Main and
893 The Received Signal Strength Indicator value. This lets
894 you know how strong a signal TeleDongle is receiving. The
895 radio inside TeleDongle operates down to about -99dBm;
896 weaker signals may not be receivable. The packet link uses
897 error correction and detection techniques which prevent
898 incorrect data from being reported.
903 Finally, the largest portion of the window contains a set of
904 tabs, each of which contain some information about the rocket.
905 They're arranged in 'flight order' so that as the flight
906 progresses, the selected tab automatically switches to display
907 data relevant to the current state of the flight. You can select
908 other tabs at any time. The final 'table' tab contains all of
909 the telemetry data in one place.
912 <title>Launch Pad</title>
914 The 'Launch Pad' tab shows information used to decide when the
915 rocket is ready for flight. The first elements include red/green
916 indicators, if any of these is red, you'll want to evaluate
917 whether the rocket is ready to launch:
921 Battery Voltage. This indicates whether the Li-Po battery
922 powering the TeleMetrum has sufficient charge to last for
923 the duration of the flight. A value of more than
924 3.7V is required for a 'GO' status.
929 Apogee Igniter Voltage. This indicates whether the apogee
930 igniter has continuity. If the igniter has a low
931 resistance, then the voltage measured here will be close
932 to the Li-Po battery voltage. A value greater than 3.2V is
933 required for a 'GO' status.
938 Main Igniter Voltage. This indicates whether the main
939 igniter has continuity. If the igniter has a low
940 resistance, then the voltage measured here will be close
941 to the Li-Po battery voltage. A value greater than 3.2V is
942 required for a 'GO' status.
947 On-board Data Logging. This indicates whether there is
948 space remaining on-board to store flight data for the
949 upcoming flight. If you've downloaded data, but failed
950 to erase flights, there may not be any space
951 left. TeleMetrum can store multiple flights, depending
952 on the configured maximum flight log size. TeleMini
953 stores only a single flight, so it will need to be
954 downloaded and erased after each flight to capture
955 data. This only affects on-board flight logging; the
956 altimeter will still transmit telemetry and fire
957 ejection charges at the proper times.
962 GPS Locked. For a TeleMetrum device, this indicates whether the GPS receiver is
963 currently able to compute position information. GPS requires
964 at least 4 satellites to compute an accurate position.
969 GPS Ready. For a TeleMetrum device, this indicates whether GPS has reported at least
970 10 consecutive positions without losing lock. This ensures
971 that the GPS receiver has reliable reception from the
977 The Launchpad tab also shows the computed launch pad position
978 and altitude, averaging many reported positions to improve the
984 <title>Ascent</title>
986 This tab is shown during Boost, Fast and Coast
987 phases. The information displayed here helps monitor the
988 rocket as it heads towards apogee.
991 The height, speed and acceleration are shown along with the
992 maximum values for each of them. This allows you to quickly
993 answer the most commonly asked questions you'll hear during
997 The current latitude and longitude reported by the TeleMetrum GPS are
998 also shown. Note that under high acceleration, these values
999 may not get updated as the GPS receiver loses position
1000 fix. Once the rocket starts coasting, the receiver should
1001 start reporting position again.
1004 Finally, the current igniter voltages are reported as in the
1005 Launch Pad tab. This can help diagnose deployment failures
1006 caused by wiring which comes loose under high acceleration.
1010 <title>Descent</title>
1012 Once the rocket has reached apogee and (we hope) activated the
1013 apogee charge, attention switches to tracking the rocket on
1014 the way back to the ground, and for dual-deploy flights,
1015 waiting for the main charge to fire.
1018 To monitor whether the apogee charge operated correctly, the
1019 current descent rate is reported along with the current
1020 height. Good descent rates generally range from 15-30m/s.
1023 For TeleMetrum altimeters, you can locate the rocket in the sky
1024 using the elevation and
1025 bearing information to figure out where to look. Elevation is
1026 in degrees above the horizon. Bearing is reported in degrees
1027 relative to true north. Range can help figure out how big the
1028 rocket will appear. Note that all of these values are relative
1029 to the pad location. If the elevation is near 90°, the rocket
1030 is over the pad, not over you.
1033 Finally, the igniter voltages are reported in this tab as
1034 well, both to monitor the main charge as well as to see what
1035 the status of the apogee charge is.
1039 <title>Landed</title>
1041 Once the rocket is on the ground, attention switches to
1042 recovery. While the radio signal is generally lost once the
1043 rocket is on the ground, the last reported GPS position is
1044 generally within a short distance of the actual landing location.
1047 The last reported GPS position is reported both by
1048 latitude and longitude as well as a bearing and distance from
1049 the launch pad. The distance should give you a good idea of
1050 whether you'll want to walk or hitch a ride. Take the reported
1051 latitude and longitude and enter them into your hand-held GPS
1052 unit and have that compute a track to the landing location.
1055 Both TeleMini and TeleMetrum will continue to transmit RDF
1056 tones after landing, allowing you to locate the rocket by
1057 following the radio signal. You may need to get away from
1058 the clutter of the flight line, or even get up on a hill (or
1059 your neighbor's RV) to receive the RDF signal.
1062 The maximum height, speed and acceleration reported
1063 during the flight are displayed for your admiring observers.
1066 To get more detailed information about the flight, you can
1067 click on the 'Graph Flight' button which will bring up a
1068 graph window for the current flight.
1072 <title>Site Map</title>
1074 When the TeleMetrum gets a GPS fix, the Site Map tab will map
1075 the rocket's position to make it easier for you to locate the
1076 rocket, both while it is in the air, and when it has landed. The
1077 rocket's state is indicated by color: white for pad, red for
1078 boost, pink for fast, yellow for coast, light blue for drogue,
1079 dark blue for main, and black for landed.
1082 The map's scale is approximately 3m (10ft) per pixel. The map
1083 can be dragged using the left mouse button. The map will attempt
1084 to keep the rocket roughly centered while data is being received.
1087 Images are fetched automatically via the Google Maps Static API,
1088 and are cached for reuse. If map images cannot be downloaded,
1089 the rocket's path will be traced on a dark gray background
1093 You can pre-load images for your favorite launch sites
1094 before you leave home; check out the 'Preload Maps' section below.
1099 <title>Packet Command Mode</title>
1100 <subtitle>Controlling An Altimeter Over The Radio Link</subtitle>
1102 One of the unique features of the Altus Metrum environment is
1103 the ability to create a two way command link between TeleDongle
1104 and an altimeter using the digital radio transceivers built into
1105 each device. This allows you to interact with the altimeter from
1106 afar, as if it were directly connected to the computer.
1109 Any operation which can be performed with TeleMetrum
1110 can either be done with TeleMetrum directly connected to
1111 the computer via the USB cable, or through the packet
1112 link. Simply select the appropriate TeleDongle device when
1113 the list of devices is presented and AltosUI will use packet
1117 One oddity in the current interface is how AltosUI selects the
1118 frequency for packet mode communications. Instead of providing
1119 an interface to specifically configure the frequency, it uses
1120 whatever frequency was most recently selected for the target
1121 TeleDongle device in Monitor Flight mode. If you haven't ever
1122 used that mode with the TeleDongle in question, select the
1123 Monitor Flight button from the top level UI, pick the
1124 appropriate TeleDongle device. Once the flight monitoring
1125 window is open, select the desired frequency and then close it
1126 down again. All Packet Command Mode operations will now use
1132 Save Flight Data—Recover flight data from the rocket without
1138 Configure altimeter apogee delays or main deploy heights
1139 to respond to changing launch conditions. You can also
1140 'reboot' the altimeter. Use this to remotely enable the
1141 flight computer by turning TeleMetrum on in "idle" mode,
1142 then once the air-frame is oriented for launch, you can
1143 reboot the altimeter and have it restart in pad mode
1144 without having to climb the scary ladder.
1149 Fire Igniters—Test your deployment charges without snaking
1150 wires out through holes in the air-frame. Simply assembly the
1151 rocket as if for flight with the apogee and main charges
1152 loaded, then remotely command the altimeter to fire the
1158 Packet command mode uses the same RF frequencies as telemetry
1159 mode. Configure the desired TeleDongle frequency using the
1160 flight monitor window frequency selector and then close that
1161 window before performing the desired operation.
1164 TeleMetrum only enables packet command mode in 'idle' mode, so
1165 make sure you have TeleMetrum lying horizontally when you turn
1166 it on. Otherwise, TeleMetrum will start in 'pad' mode ready for
1167 flight and will not be listening for command packets from TeleDongle.
1170 TeleMini listens for a command packet for five seconds after
1171 first being turned on, if it doesn't hear anything, it enters
1172 'pad' mode, ready for flight and will no longer listen for
1176 When packet command mode is enabled, you can monitor the link
1177 by watching the lights on the
1178 devices. The red LED will flash each time they
1179 transmit a packet while the green LED will light up
1180 on TeleDongle while it is waiting to receive a packet from
1185 <title>Save Flight Data</title>
1187 The altimeter records flight data to its internal flash memory.
1188 The TeleMetrum data is recorded at a much higher rate than the telemetry
1189 system can handle, and is not subject to radio drop-outs. As
1190 such, it provides a more complete and precise record of the
1191 flight. The 'Save Flight Data' button allows you to read the
1192 flash memory and write it to disk. As TeleMini has only a barometer, it
1193 records data at the same rate as the telemetry signal, but there will be
1194 no data lost due to telemetry drop-outs.
1197 Clicking on the 'Save Flight Data' button brings up a list of
1198 connected TeleMetrum and TeleDongle devices. If you select a
1199 TeleMetrum device, the flight data will be downloaded from that
1200 device directly. If you select a TeleDongle device, flight data
1201 will be downloaded from a TeleMetrum or TeleMini device connected via the
1202 packet command link to the specified TeleDongle. See the chapter
1203 on Packet Command Mode for more information about this.
1206 After the device has been selected, a dialog showing the
1207 flight data saved in the device will be shown allowing you to
1208 select which flights to download and which to delete. With
1209 version 0.9 or newer firmware, you must erase flights in order
1210 for the space they consume to be reused by another
1211 flight. This prevents you from accidentally losing flight data
1212 if you neglect to download data before flying again. Note that
1213 if there is no more space available in the device, then no
1214 data will be recorded for a flight.
1217 The file name for each flight log is computed automatically
1218 from the recorded flight date, altimeter serial number and
1219 flight number information.
1223 <title>Replay Flight</title>
1225 Select this button and you are prompted to select a flight
1226 record file, either a .telem file recording telemetry data or a
1227 .eeprom file containing flight data saved from the altimeter
1231 Once a flight record is selected, the flight monitor interface
1232 is displayed and the flight is re-enacted in real time. Check
1233 the Monitor Flight chapter above to learn how this window operates.
1237 <title>Graph Data</title>
1239 Select this button and you are prompted to select a flight
1240 record file, either a .telem file recording telemetry data or a
1241 .eeprom file containing flight data saved from
1245 Once a flight record is selected, a window with two tabs is
1246 opened. The first tab contains a graph with acceleration
1247 (blue), velocity (green) and altitude (red) of the flight are
1248 plotted and displayed, measured in metric units. The
1249 apogee(yellow) and main(magenta) igniter voltages are also
1250 displayed; high voltages indicate continuity, low voltages
1251 indicate open circuits. The second tab contains some basic
1255 The graph can be zoomed into a particular area by clicking and
1256 dragging down and to the right. Once zoomed, the graph can be
1257 reset by clicking and dragging up and to the left. Holding down
1258 control and clicking and dragging allows the graph to be panned.
1259 The right mouse button causes a pop-up menu to be displayed, giving
1260 you the option save or print the plot.
1263 Note that telemetry files will generally produce poor graphs
1264 due to the lower sampling rate and missed telemetry packets.
1265 Use saved flight data for graphing where possible.
1269 <title>Export Data</title>
1271 This tool takes the raw data files and makes them available for
1272 external analysis. When you select this button, you are prompted to select a flight
1273 data file (either .eeprom or .telem will do, remember that
1274 .eeprom files contain higher resolution and more continuous
1275 data). Next, a second dialog appears which is used to select
1276 where to write the resulting file. It has a selector to choose
1277 between CSV and KML file formats.
1280 <title>Comma Separated Value Format</title>
1282 This is a text file containing the data in a form suitable for
1283 import into a spreadsheet or other external data analysis
1284 tool. The first few lines of the file contain the version and
1285 configuration information from the altimeter, then
1286 there is a single header line which labels all of the
1287 fields. All of these lines start with a '#' character which
1288 most tools can be configured to skip over.
1291 The remaining lines of the file contain the data, with each
1292 field separated by a comma and at least one space. All of
1293 the sensor values are converted to standard units, with the
1294 barometric data reported in both pressure, altitude and
1295 height above pad units.
1299 <title>Keyhole Markup Language (for Google Earth)</title>
1301 This is the format used by
1302 Googleearth to provide an overlay within that
1303 application. With this, you can use Googleearth to see the
1304 whole flight path in 3D.
1309 <title>Configure Altimeter</title>
1311 Select this button and then select either a TeleMetrum or
1312 TeleDongle Device from the list provided. Selecting a TeleDongle
1313 device will use Packet Command Mode to configure a remote
1314 altimeter. Learn how to use this in the Packet Command
1318 The first few lines of the dialog provide information about the
1319 connected device, including the product name,
1320 software version and hardware serial number. Below that are the
1321 individual configuration entries.
1324 At the bottom of the dialog, there are four buttons:
1329 Save. This writes any changes to the
1330 configuration parameter block in flash memory. If you don't
1331 press this button, any changes you make will be lost.
1336 Reset. This resets the dialog to the most recently saved values,
1337 erasing any changes you have made.
1342 Reboot. This reboots the device. Use this to
1343 switch from idle to pad mode by rebooting once the rocket is
1344 oriented for flight.
1349 Close. This closes the dialog. Any unsaved changes will be
1355 The rest of the dialog contains the parameters to be configured.
1358 <title>Main Deploy Altitude</title>
1360 This sets the altitude (above the recorded pad altitude) at
1361 which the 'main' igniter will fire. The drop-down menu shows
1362 some common values, but you can edit the text directly and
1363 choose whatever you like. If the apogee charge fires below
1364 this altitude, then the main charge will fire two seconds
1365 after the apogee charge fires.
1369 <title>Apogee Delay</title>
1371 When flying redundant electronics, it's often important to
1372 ensure that multiple apogee charges don't fire at precisely
1373 the same time as that can over pressurize the apogee deployment
1374 bay and cause a structural failure of the air-frame. The Apogee
1375 Delay parameter tells the flight computer to fire the apogee
1376 charge a certain number of seconds after apogee has been
1381 <title>Radio Frequency</title>
1383 This configures which of the configured frequencies to use for both
1384 telemetry and packet command mode. Note that if you set this
1385 value via packet command mode, you will have to reconfigure
1386 the TeleDongle frequency before you will be able to use packet
1391 <title>Radio Calibration</title>
1393 The radios in every Altus Metrum device are calibrated at the
1394 factory to ensure that they transmit and receive on the
1395 specified frequency. You can adjust that
1396 calibration by changing this value. To change the TeleDongle's
1397 calibration, you must reprogram the unit completely.
1401 <title>Callsign</title>
1403 This sets the call sign included in each telemetry packet. Set this
1404 as needed to conform to your local radio regulations.
1408 <title>Maximum Flight Log Size</title>
1410 This sets the space (in kilobytes) allocated for each flight
1411 log. The available space will be divided into chunks of this
1412 size. A smaller value will allow more flights to be stored,
1413 a larger value will record data from longer flights.
1416 During ascent, TeleMetrum records barometer and
1417 accelerometer values 100 times per second, other analog
1418 information (voltages and temperature) 6 times per second
1419 and GPS data once per second. During descent, the non-GPS
1420 data is recorded 1/10th as often. Each barometer +
1421 accelerometer record takes 8 bytes.
1424 The default, 192kB, will store over 200 seconds of data at
1425 the ascent rate, or over 2000 seconds of data at the descent
1426 rate. That's plenty for most flights. This leaves enough
1427 storage for five flights in a 1MB system, or 10 flights in a
1431 The configuration block takes the last available block of
1432 memory, on v1.0 boards that's just 256 bytes. However, the
1433 flash part on the v1.1 boards uses 64kB for each block.
1436 TeleMini has 5kB of on-board storage, which is plenty for a
1437 single flight. Make sure you download and delete the data
1438 before a subsequent flight or it will not log any data.
1442 <title>Ignite Mode</title>
1444 TeleMetrum and TeleMini provide two igniter channels as they
1445 were originally designed as dual-deploy flight
1446 computers. This configuration parameter allows the two
1447 channels to be used in different configurations.
1452 Dual Deploy. This is the usual mode of operation; the
1453 'apogee' channel is fired at apogee and the 'main'
1454 channel at the height above ground specified by the
1455 'Main Deploy Altitude' during descent.
1460 Redundant Apogee. This fires both channels at
1461 apogee, the 'apogee' channel first followed after a two second
1462 delay by the 'main' channel.
1467 Redundant Main. This fires both channels at the
1468 height above ground specified by the Main Deploy
1469 Altitude setting during descent. The 'apogee'
1470 channel is fired first, followed after a two second
1471 delay by the 'main' channel.
1477 <title>Pad Orientation</title>
1479 Because it includes an accelerometer, TeleMetrum is
1480 sensitive to the orientation of the board. By default, it
1481 expects the antenna end to point forward. This parameter
1482 allows that default to be changed, permitting the board to
1483 be mounted with the antenna pointing aft instead.
1488 Antenna Up. In this mode, the antenna end of the
1489 TeleMetrum board must point forward, in line with the
1490 expected flight path.
1495 Antenna Down. In this mode, the antenna end of the
1496 TeleMetrum board must point aft, in line with the
1497 expected flight path.
1504 <title>Configure AltosUI</title>
1506 This button presents a dialog so that you can configure the AltosUI global settings.
1509 <title>Voice Settings</title>
1511 AltosUI provides voice announcements during flight so that you
1512 can keep your eyes on the sky and still get information about
1513 the current flight status. However, sometimes you don't want
1518 <para>Enable—turns all voice announcements on and off</para>
1522 Test Voice—Plays a short message allowing you to verify
1523 that the audio system is working and the volume settings
1530 <title>Log Directory</title>
1532 AltosUI logs all telemetry data and saves all TeleMetrum flash
1533 data to this directory. This directory is also used as the
1534 staring point when selecting data files for display or export.
1537 Click on the directory name to bring up a directory choosing
1538 dialog, select a new directory and click 'Select Directory' to
1539 change where AltosUI reads and writes data files.
1543 <title>Callsign</title>
1545 This value is used in command packet mode and is transmitted
1546 in each packet sent from TeleDongle and received from
1547 TeleMetrum. It is not used in telemetry mode as that transmits
1548 packets only from TeleMetrum to TeleDongle. Configure this
1549 with the AltosUI operators call sign as needed to comply with
1550 your local radio regulations.
1554 <title>Font Size</title>
1556 Selects the set of fonts used in the flight monitor
1557 window. Choose between the small, medium and large sets.
1561 <title>Serial Debug</title>
1563 This causes all communication with a connected device to be
1564 dumped to the console from which AltosUI was started. If
1565 you've started it from an icon or menu entry, the output
1566 will simply be discarded. This mode can be useful to debug
1567 various serial communication issues.
1571 <title>Manage Frequencies</title>
1573 This brings up a dialog where you can configure the set of
1574 frequencies shown in the various frequency menus. You can
1575 add as many as you like, or even reconfigure the default
1576 set. Changing this list does not affect the frequency
1577 settings of any devices, it only changes the set of
1578 frequencies shown in the menus.
1583 <title>Flash Image</title>
1585 This reprograms any Altus Metrum device by using a TeleMetrum
1586 or TeleDongle as a programming dongle. Please read the
1587 directions for flashing devices in the Updating Device
1588 Firmware section above
1591 Once you have the programmer and target devices connected,
1592 push the 'Flash Image' button. That will present a dialog box
1593 listing all of the connected devices. Carefully select the
1594 programmer device, not the device to be programmed.
1597 Next, select the image to flash to the device. These are named
1598 with the product name and firmware version. The file selector
1599 will start in the directory containing the firmware included
1600 with the AltosUI package. Navigate to the directory containing
1601 the desired firmware if it isn't there.
1604 Next, a small dialog containing the device serial number and
1605 RF calibration values should appear. If these values are
1606 incorrect (possibly due to a corrupted image in the device),
1607 enter the correct values here.
1610 Finally, a dialog containing a progress bar will follow the
1611 programming process.
1614 When programming is complete, the target device will
1615 reboot. Note that if the target device is connected via USB, you
1616 will have to unplug it and then plug it back in for the USB
1617 connection to reset so that you can communicate with the device
1622 <title>Fire Igniter</title>
1624 This activates the igniter circuits in TeleMetrum to help test
1625 recovery systems deployment. Because this command can operate
1626 over the Packet Command Link, you can prepare the rocket as
1627 for flight and then test the recovery system without needing
1628 to snake wires inside the air-frame.
1631 Selecting the 'Fire Igniter' button brings up the usual device
1632 selection dialog. Pick the desired TeleDongle or TeleMetrum
1633 device. This brings up another window which shows the current
1634 continuity test status for both apogee and main charges.
1637 Next, select the desired igniter to fire. This will enable the
1641 Select the 'Arm' button. This enables the 'Fire' button. The
1642 word 'Arm' is replaced by a countdown timer indicating that
1643 you have 10 seconds to press the 'Fire' button or the system
1644 will deactivate, at which point you start over again at
1645 selecting the desired igniter.
1649 <title>Scan Channels</title>
1651 This listens for telemetry packets on all of the configured
1652 frequencies, displaying information about each device it
1653 receives a packet from. You can select which of the three
1654 telemetry formats should be tried; by default, it only listens
1655 for the standard telemetry packets used in v1.0 and later
1660 <title>Load Maps</title>
1662 Before heading out to a new launch site, you can use this to
1663 load satellite images in case you don't have internet
1664 connectivity at the site. This loads a fairly large area
1665 around the launch site, which should cover any flight you're likely to make.
1668 There's a drop-down menu of launch sites we know about; if
1669 your favorites aren't there, please let us know the lat/lon
1670 and name of the site. The contents of this list are actually
1671 downloaded at run-time, so as new sites are sent in, they'll
1672 get automatically added to this list.
1675 If the launch site isn't in the list, you can manually enter the lat/lon values
1678 Clicking the 'Load Map' button will fetch images from Google
1679 Maps; note that Google limits how many images you can fetch at
1680 once, so if you load more than one launch site, you may get
1681 some gray areas in the map which indicate that Google is tired
1682 of sending data to you. Try again later.
1686 <title>Monitor Idle</title>
1688 This brings up a dialog similar to the Monitor Flight UI,
1689 except it works with the altimeter in "idle" mode by sending
1690 query commands to discover the current state rather than
1691 listening for telemetry packets.
1696 <title>Using Altus Metrum Products</title>
1698 <title>Being Legal</title>
1700 First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
1701 other authorization to legally operate the radio transmitters that are part
1706 <title>In the Rocket</title>
1708 In the rocket itself, you just need a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> or
1709 <ulink url="http://www.altusmetrum.org/TeleMini/">TeleMini</ulink> board and
1710 a Li-Po rechargeable battery. An 860mAh battery weighs less than a 9V
1711 alkaline battery, and will run a TeleMetrum for hours.
1712 A 110mAh battery weighs less than a triple A battery and will run a TeleMetrum for
1713 a few hours, or a TeleMini for much (much) longer.
1716 By default, we ship the altimeters with a simple wire antenna. If your
1717 electronics bay or the air-frame it resides within is made of carbon fiber,
1718 which is opaque to RF signals, you may choose to have an SMA connector
1719 installed so that you can run a coaxial cable to an antenna mounted
1720 elsewhere in the rocket.
1724 <title>On the Ground</title>
1726 To receive the data stream from the rocket, you need an antenna and short
1727 feed-line connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> units. The
1728 TeleDongle in turn plugs directly into the USB port on a notebook
1729 computer. Because TeleDongle looks like a simple serial port, your computer
1730 does not require special device drivers... just plug it in.
1733 The GUI tool, AltosUI, is written in Java and runs across
1734 Linux, Mac OS and Windows. There's also a suite of C tools
1735 for Linux which can perform most of the same tasks.
1738 After the flight, you can use the RF link to extract the more detailed data
1739 logged in either TeleMetrum or TeleMini devices, or you can use a mini USB cable to plug into the
1740 TeleMetrum board directly. Pulling out the data without having to open up
1741 the rocket is pretty cool! A USB cable is also how you charge the Li-Po
1742 battery, so you'll want one of those anyway... the same cable used by lots
1743 of digital cameras and other modern electronic stuff will work fine.
1746 If your TeleMetrum-equipped rocket lands out of sight, you may enjoy having a hand-held GPS
1747 receiver, so that you can put in a way-point for the last reported rocket
1748 position before touch-down. This makes looking for your rocket a lot like
1749 Geo-Caching... just go to the way-point and look around starting from there.
1752 You may also enjoy having a ham radio "HT" that covers the 70cm band... you
1753 can use that with your antenna to direction-find the rocket on the ground
1754 the same way you can use a Walston or Beeline tracker. This can be handy
1755 if the rocket is hiding in sage brush or a tree, or if the last GPS position
1756 doesn't get you close enough because the rocket dropped into a canyon, or
1757 the wind is blowing it across a dry lake bed, or something like that... Keith
1758 and Bdale both currently own and use the Yaesu VX-7R at launches.
1761 So, to recap, on the ground the hardware you'll need includes:
1762 <orderedlist inheritnum='inherit' numeration='arabic'>
1764 an antenna and feed-line
1773 optionally, a hand-held GPS receiver
1776 optionally, an HT or receiver covering 435 MHz
1781 The best hand-held commercial directional antennas we've found for radio
1782 direction finding rockets are from
1783 <ulink url="http://www.arrowantennas.com/" >
1786 The 440-3 and 440-5 are both good choices for finding a
1787 TeleMetrum- or TeleMini- equipped rocket when used with a suitable 70cm HT.
1791 <title>Data Analysis</title>
1793 Our software makes it easy to log the data from each flight, both the
1794 telemetry received over the RF link during the flight itself, and the more
1795 complete data log recorded in the flash memory on the altimeter
1796 board. Once this data is on your computer, our post-flight tools make it
1797 easy to quickly get to the numbers everyone wants, like apogee altitude,
1798 max acceleration, and max velocity. You can also generate and view a
1799 standard set of plots showing the altitude, acceleration, and
1800 velocity of the rocket during flight. And you can even export a TeleMetrum data file
1801 usable with Google Maps and Google Earth for visualizing the flight path
1802 in two or three dimensions!
1805 Our ultimate goal is to emit a set of files for each flight that can be
1806 published as a web page per flight, or just viewed on your local disk with
1811 <title>Future Plans</title>
1813 In the future, we intend to offer "companion boards" for the rocket that will
1814 plug in to TeleMetrum to collect additional data, provide more pyro channels,
1815 and so forth. A reference design for a companion board will be documented
1816 soon, and will be compatible with open source Arduino programming tools.
1819 We are also working on the design of a hand-held ground terminal that will
1820 allow monitoring the rocket's status, collecting data during flight, and
1821 logging data after flight without the need for a notebook computer on the
1822 flight line. Particularly since it is so difficult to read most notebook
1823 screens in direct sunlight, we think this will be a great thing to have.
1826 Because all of our work is open, both the hardware designs and the software,
1827 if you have some great idea for an addition to the current Altus Metrum family,
1828 feel free to dive in and help! Or let us know what you'd like to see that
1829 we aren't already working on, and maybe we'll get excited about it too...
1834 <title>Altimeter Installation Recommendations</title>
1836 Building high-power rockets that fly safely is hard enough. Mix
1837 in some sophisticated electronics and a bunch of radio energy
1838 and oftentimes you find few perfect solutions. This chapter
1839 contains some suggestions about how to install Altus Metrum
1840 products into the rocket air-frame, including how to safely and
1841 reliably mix a variety of electronics into the same air-frame.
1844 <title>Mounting the Altimeter</title>
1846 The first consideration is to ensure that the altimeter is
1847 securely fastened to the air-frame. For TeleMetrum, we use
1848 nylon standoffs and nylon screws; they're good to at least 50G
1849 and cannot cause any electrical issues on the board. For
1850 TeleMini, we usually cut small pieces of 1/16" balsa to fit
1851 under the screw holes, and then take 2x56 nylon screws and
1852 screw them through the TeleMini mounting holes, through the
1853 balsa and into the underlying material.
1855 <orderedlist inheritnum='inherit' numeration='arabic'>
1857 Make sure TeleMetrum is aligned precisely along the axis of
1858 acceleration so that the accelerometer can accurately
1859 capture data during the flight.
1862 Watch for any metal touching components on the
1863 board. Shorting out connections on the bottom of the board
1864 can cause the altimeter to fail during flight.
1869 <title>Dealing with the Antenna</title>
1871 The antenna supplied is just a piece of solid, insulated,
1872 wire. If it gets damaged or broken, it can be easily
1873 replaced. It should be kept straight and not cut; bending or
1874 cutting it will change the resonant frequency and/or
1875 impedance, making it a less efficient radiator and thus
1876 reducing the range of the telemetry signal.
1879 Keeping metal away from the antenna will provide better range
1880 and a more even radiation pattern. In most rockets, it's not
1881 entirely possible to isolate the antenna from metal
1882 components; there are often bolts, all-thread and wires from other
1883 electronics to contend with. Just be aware that the more stuff
1884 like this around the antenna, the lower the range.
1887 Make sure the antenna is not inside a tube made or covered
1888 with conducting material. Carbon fiber is the most common
1889 culprit here -- CF is a good conductor and will effectively
1890 shield the antenna, dramatically reducing signal strength and
1891 range. Metallic flake paint is another effective shielding
1892 material which is to be avoided around any antennas.
1895 If the ebay is large enough, it can be convenient to simply
1896 mount the altimeter at one end and stretch the antenna out
1897 inside. Taping the antenna to the sled can keep it straight
1898 under acceleration. If there are metal rods, keep the
1899 antenna as far away as possible.
1902 For a shorter ebay, it's quite practical to have the antenna
1903 run through a bulkhead and into an adjacent bay. Drill a small
1904 hole in the bulkhead, pass the antenna wire through it and
1905 then seal it up with glue or clay. We've also used acrylic
1906 tubing to create a cavity for the antenna wire. This works a
1907 bit better in that the antenna is known to stay straight and
1908 not get folded by recovery components in the bay. Angle the
1909 tubing towards the side wall of the rocket and it ends up
1910 consuming very little space.
1913 If you need to place the antenna at a distance from the
1914 altimeter, you can replace the antenna with an edge-mounted
1915 SMA connector, and then run 50Ω coax from the board to the
1916 antenna. Building a remote antenna is beyond the scope of this
1921 <title>Preserving GPS Reception</title>
1923 The GPS antenna and receiver in TeleMetrum are highly
1924 sensitive and normally have no trouble tracking enough
1925 satellites to provide accurate position information for
1926 recovering the rocket. However, there are many ways to
1927 attenuate the GPS signal.
1928 <orderedlist inheritnum='inherit' numeration='arabic'>
1930 Conductive tubing or coatings. Carbon fiber and metal
1931 tubing, or metallic paint will all dramatically attenuate the
1932 GPS signal. We've never heard of anyone successfully
1933 receiving GPS from inside these materials.
1936 Metal components near the GPS patch antenna. These will
1937 de-tune the patch antenna, changing the resonant frequency
1938 away from the L1 carrier and reduce the effectiveness of the
1939 antenna. You can place as much stuff as you like beneath the
1940 antenna as that's covered with a ground plane. But, keep
1941 wires and metal out from above the patch antenna.
1947 <title>Radio Frequency Interference</title>
1949 Any altimeter will generate RFI; the digital circuits use
1950 high-frequency clocks that spray radio interference across a
1951 wide band. Altusmetrum altimeters generate intentional radio
1952 signals as well, increasing the amount of RF energy around the board.
1955 Rocketry altimeters also use precise sensors measuring air
1956 pressure and acceleration. Tiny changes in voltage can cause
1957 these sensor readings to vary by a huge amount. When the
1958 sensors start mis-reporting data, the altimeter can either
1959 fire the igniters at the wrong time, or not fire them at all.
1962 Voltages are induced when radio frequency energy is
1963 transmitted from one circuit to another. Here are things that
1964 increase the induced voltage and current:
1968 Keep wires from different circuits apart. Moving circuits
1969 further apart will reduce RFI.
1972 Avoid parallel wires from different circuits. The longer two
1973 wires run parallel to one another, the larger the amount of
1974 transferred energy. Cross wires at right angles to reduce
1978 Twist wires from the same circuits. Two wires the same
1979 distance from the transmitter will get the same amount of
1980 induced energy which will then cancel out. Any time you have
1981 a wire pair running together, twist the pair together to
1982 even out distances and reduce RFI. For altimeters, this
1983 includes battery leads, switch hookups and igniter
1987 Avoid resonant lengths. Know what frequencies are present
1988 in the environment and avoid having wire lengths near a
1989 natural resonant length. Altusmetrum products transmit on the
1990 70cm amateur band, so you should avoid lengths that are a
1991 simple ratio of that length; essentially any multiple of 1/4
1992 of the wavelength (17.5cm).
1997 <title>The Barometric Sensor</title>
1999 Altusmetrum altimeters measure altitude with a barometric
2000 sensor, essentially measuring the amount of air above the
2001 rocket to figure out how high it is. A large number of
2002 measurements are taken as the altimeter initializes itself to
2003 figure out the pad altitude. Subsequent measurements are then
2004 used to compute the height above the pad.
2007 To accurately measure atmospheric pressure, the ebay
2008 containing the altimeter must be vented outside the
2009 air-frame. The vent must be placed in a region of linear
2010 airflow, smooth and not in an area of increasing or decreasing
2014 The barometric sensor in the altimeter is quite sensitive to
2015 chemical damage from the products of APCP or BP combustion, so
2016 make sure the ebay is carefully sealed from any compartment
2017 which contains ejection charges or motors.
2021 <title>Ground Testing</title>
2023 The most important aspect of any installation is careful
2024 ground testing. Bringing an air-frame up to the LCO table which
2025 hasn't been ground tested can lead to delays or ejection
2026 charges firing on the pad, or, even worse, a recovery system
2030 Do a 'full systems' test that includes wiring up all igniters
2031 without any BP and turning on all of the electronics in flight
2032 mode. This will catch any mistakes in wiring and any residual
2033 RFI issues that might accidentally fire igniters at the wrong
2034 time. Let the air-frame sit for several minutes, checking for
2035 adequate telemetry signal strength and GPS lock.
2038 Ground test the ejection charges. Prepare the rocket for
2039 flight, loading ejection charges and igniters. Completely
2040 assemble the air-frame and then use the 'Fire Igniters'
2041 interface through a TeleDongle to command each charge to
2042 fire. Make sure the charge is sufficient to robustly separate
2043 the air-frame and deploy the recovery system.
2048 <title>Hardware Specifications</title>
2050 <title>TeleMetrum Specifications</title>
2054 Recording altimeter for model rocketry.
2059 Supports dual deployment (can fire 2 ejection charges).
2064 70cm ham-band transceiver for telemetry down-link.
2069 Barometric pressure sensor good to 45k feet MSL.
2074 1-axis high-g accelerometer for motor characterization, capable of
2075 +/- 50g using default part.
2080 On-board, integrated GPS receiver with 5Hz update rate capability.
2085 On-board 1 megabyte non-volatile memory for flight data storage.
2090 USB interface for battery charging, configuration, and data recovery.
2095 Fully integrated support for Li-Po rechargeable batteries.
2100 Uses Li-Po to fire e-matches, can be modified to support
2101 optional separate pyro battery if needed.
2106 2.75 x 1 inch board designed to fit inside 29mm air-frame coupler tube.
2112 <title>TeleMini Specifications</title>
2116 Recording altimeter for model rocketry.
2121 Supports dual deployment (can fire 2 ejection charges).
2126 70cm ham-band transceiver for telemetry down-link.
2131 Barometric pressure sensor good to 45k feet MSL.
2136 On-board 5 kilobyte non-volatile memory for flight data storage.
2141 RF interface for battery charging, configuration, and data recovery.
2146 Support for Li-Po rechargeable batteries, using an external charger.
2151 Uses Li-Po to fire e-matches, can be modified to support
2152 optional separate pyro battery if needed.
2157 1.5 x .5 inch board designed to fit inside 18mm air-frame coupler tube.
2166 TeleMetrum seems to shut off when disconnected from the
2167 computer. Make sure the battery is adequately charged. Remember the
2168 unit will pull more power than the USB port can deliver before the
2169 GPS enters "locked" mode. The battery charges best when TeleMetrum
2173 It's impossible to stop the TeleDongle when it's in "p" mode, I have
2174 to unplug the USB cable? Make sure you have tried to "escape out" of
2175 this mode. If this doesn't work the reboot procedure for the
2176 TeleDongle *is* to simply unplug it. 'cu' however will retain it's
2177 outgoing buffer IF your "escape out" ('~~') does not work.
2178 At this point using either 'ao-view' (or possibly
2179 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
2183 The amber LED (on the TeleMetrum) lights up when both
2184 battery and USB are connected. Does this mean it's charging?
2185 Yes, the yellow LED indicates the charging at the 'regular' rate.
2186 If the led is out but the unit is still plugged into a USB port,
2187 then the battery is being charged at a 'trickle' rate.
2190 There are no "dit-dah-dah-dit" sound or lights like the manual mentions?
2191 That's the "pad" mode. Weak batteries might be the problem.
2192 It is also possible that the TeleMetrum is horizontal and the output
2193 is instead a "dit-dit" meaning 'idle'. For TeleMini, it's possible that
2194 it received a command packet which would have left it in "pad" mode.
2197 How do I save flight data?
2198 Live telemetry is written to file(s) whenever AltosUI is connected
2199 to the TeleDongle. The file area defaults to ~/TeleMetrum
2200 but is easily changed using the menus in AltosUI. The files that
2201 are written end in '.telem'. The after-flight
2202 data-dumped files will end in .eeprom and represent continuous data
2203 unlike the RF-linked .telem files that are subject to losses
2204 along the RF data path.
2205 See the above instructions on what and how to save the eeprom stored
2206 data after physically retrieving your altimeter. Make sure to save
2207 the on-board data after each flight; while the TeleMetrum can store
2208 multiple flights, you never know when you'll lose the altimeter...
2212 <title>Notes for Older Software</title>
2215 Before AltosUI was written, using Altus Metrum devices required
2216 some finesse with the Linux command line. There was a limited
2217 GUI tool, ao-view, which provided functionality similar to the
2218 Monitor Flight window in AltosUI, but everything else was a
2219 fairly 80's experience. This appendix includes documentation for
2220 using that software.
2224 Both TeleMetrum and TeleDongle can be directly communicated
2225 with using USB ports. The first thing you should try after getting
2226 both units plugged into to your computer's USB port(s) is to run
2227 'ao-list' from a terminal-window to see what port-device-name each
2228 device has been assigned by the operating system.
2229 You will need this information to access the devices via their
2230 respective on-board firmware and data using other command line
2231 programs in the AltOS software suite.
2234 TeleMini can be communicated with through a TeleDongle device
2235 over the radio link. When first booted, TeleMini listens for a
2236 TeleDongle device and if it receives a packet, it goes into
2237 'idle' mode. Otherwise, it goes into 'pad' mode and waits to be
2238 launched. The easiest way to get it talking is to start the
2239 communication link on the TeleDongle and the power up the
2243 To access the device's firmware for configuration you need a terminal
2244 program such as you would use to talk to a modem. The software
2245 authors prefer using the program 'cu' which comes from the UUCP package
2246 on most Unix-like systems such as Linux. An example command line for
2247 cu might be 'cu -l /dev/ttyACM0', substituting the correct number
2248 indicated from running the
2249 ao-list program. Another reasonable terminal program for Linux is
2250 'cutecom'. The default 'escape'
2251 character used by CU (i.e. the character you use to
2252 issue commands to cu itself instead of sending the command as input
2253 to the connected device) is a '~'. You will need this for use in
2254 only two different ways during normal operations. First is to exit
2255 the program by sending a '~.' which is called a 'escape-disconnect'
2256 and allows you to close-out from 'cu'. The
2257 second use will be outlined later.
2260 All of the Altus Metrum devices share the concept of a two level
2261 command set in their firmware.
2262 The first layer has several single letter commands. Once
2263 you are using 'cu' (or 'cutecom') sending (typing) a '?'
2264 returns a full list of these
2265 commands. The second level are configuration sub-commands accessed
2266 using the 'c' command, for
2267 instance typing 'c?' will give you this second level of commands
2268 (all of which require the
2269 letter 'c' to access). Please note that most configuration options
2270 are stored only in Flash memory; TeleDongle doesn't provide any storage
2271 for these options and so they'll all be lost when you unplug it.
2274 Try setting these configuration ('c' or second level menu) values. A good
2275 place to start is by setting your call sign. By default, the boards
2276 use 'N0CALL' which is cute, but not exactly legal!
2277 Spend a few minutes getting comfortable with the units, their
2278 firmware, and 'cu' (or possibly 'cutecom').
2279 For instance, try to send
2280 (type) a 'c r 2' and verify the channel change by sending a 'c s'.
2281 Verify you can connect and disconnect from the units while in your
2282 terminal program by sending the escape-disconnect mentioned above.
2285 Note that the 'reboot' command, which is very useful on the altimeters,
2286 will likely just cause problems with the dongle. The *correct* way
2287 to reset the dongle is just to unplug and re-plug it.
2290 A fun thing to do at the launch site and something you can do while
2291 learning how to use these units is to play with the RF-link access
2292 between an altimeter and the TeleDongle. Be aware that you *must* create
2293 some physical separation between the devices, otherwise the link will
2294 not function due to signal overload in the receivers in each device.
2297 Now might be a good time to take a break and read the rest of this
2298 manual, particularly about the two "modes" that the altimeters
2299 can be placed in. TeleMetrum uses the position of the device when booting
2300 up will determine whether the unit is in "pad" or "idle" mode. TeleMini
2301 enters "idle" mode when it receives a command packet within the first 5 seconds
2302 of being powered up, otherwise it enters "pad" mode.
2305 You can access an altimeter in idle mode from the TeleDongle's USB
2306 connection using the RF link
2307 by issuing a 'p' command to the TeleDongle. Practice connecting and
2308 disconnecting ('~~' while using 'cu') from the altimeter. If
2309 you cannot escape out of the "p" command, (by using a '~~' when in
2310 CU) then it is likely that your kernel has issues. Try a newer version.
2313 Using this RF link allows you to configure the altimeter, test
2314 fire e-matches and igniters from the flight line, check pyro-match
2315 continuity and so forth. You can leave the unit turned on while it
2316 is in 'idle mode' and then place the
2317 rocket vertically on the launch pad, walk away and then issue a
2318 reboot command. The altimeter will reboot and start sending data
2319 having changed to the "pad" mode. If the TeleDongle is not receiving
2320 this data, you can disconnect 'cu' from the TeleDongle using the
2321 procedures mentioned above and THEN connect to the TeleDongle from
2322 inside 'ao-view'. If this doesn't work, disconnect from the
2323 TeleDongle, unplug it, and try again after plugging it back in.
2326 In order to reduce the chance of accidental firing of pyrotechnic
2327 charges, the command to fire a charge is intentionally somewhat
2328 difficult to type, and the built-in help is slightly cryptic to
2329 prevent accidental echoing of characters from the help text back at
2330 the board from firing a charge. The command to fire the apogee
2331 drogue charge is 'i DoIt drogue' and the command to fire the main
2332 charge is 'i DoIt main'.
2335 On TeleMetrum, the GPS will eventually find enough satellites, lock in on them,
2336 and 'ao-view' will both auditorily announce and visually indicate
2338 Now you can launch knowing that you have a good data path and
2339 good satellite lock for flight data and recovery. Remember
2340 you MUST tell ao-view to connect to the TeleDongle explicitly in
2341 order for ao-view to be able to receive data.
2344 The altimeters provide RDF (radio direction finding) tones on
2345 the pad, during descent and after landing. These can be used to
2346 locate the rocket using a directional antenna; the signal
2347 strength providing an indication of the direction from receiver to rocket.
2350 TeleMetrum also provides GPS trekking data, which can further simplify
2351 locating the rocket once it has landed. (The last good GPS data
2352 received before touch-down will be on the data screen of 'ao-view'.)
2355 Once you have recovered the rocket you can download the eeprom
2356 contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over
2357 either a USB cable or over the radio link using TeleDongle.
2358 And by following the man page for 'ao-postflight' you can create
2359 various data output reports, graphs, and even KML data to see the
2360 flight trajectory in Google-earth. (Moving the viewing angle making
2361 sure to connect the yellow lines while in Google-earth is the proper
2365 As for ao-view.... some things are in the menu but don't do anything
2366 very useful. The developers have stopped working on ao-view to focus
2367 on a new, cross-platform ground station program. So ao-view may or
2368 may not be updated in the future. Mostly you just use
2369 the Log and Device menus. It has a wonderful display of the incoming
2370 flight data and I am sure you will enjoy what it has to say to you
2371 once you enable the voice output!
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