1 <?xml version="1.0" encoding="utf-8" ?>
2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "/usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd">
5 <title>The Altus Metrum System</title>
6 <subtitle>An Owner's Manual for 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 default 1/4
235 wave UHF wire antenna attached to the center of the nose-cone end of
236 the board is about 7 inches long, and wiring for a power switch and
237 the e-matches for apogee and main ejection charges depart from the
238 fin can end of the board. Given all this, an ideal "simple" avionics
239 bay for TeleMetrum should have at least 10 inches of interior length.
242 TeleMini is a 0.5 inch by 1.5 inch circuit board. It was designed to
243 fit inside an 18mm air-frame tube, but using it in a tube that
244 small in diameter may require some creativity in mounting and wiring
245 to succeed! The default 1/4
246 wave UHF wire antenna attached to the center of the nose-cone end of
247 the board is about 7 inches long, and wiring for a power switch and
248 the e-matches for apogee and main ejection charges depart from the
249 fin can end of the board. Given all this, an ideal "simple" avionics
250 bay for TeleMini should have at least 9 inches of interior length.
253 A typical TeleMetrum or TeleMini installation using the on-board devices and
254 default wire UHF antenna involves attaching only a suitable
255 Lithium Polymer battery, a single pole switch for power on/off, and
256 two pairs of wires connecting e-matches for the apogee and main ejection
260 By default, we use the unregulated output of the Li-Po battery directly
261 to fire ejection charges. This works marvelously with standard
262 low-current e-matches like the J-Tek from MJG Technologies, and with
263 Quest Q2G2 igniters. However, if you
264 want or need to use a separate pyro battery, check out the "External Pyro Battery"
265 section in this manual for instructions on how to wire that up. The
266 altimeters are designed to work with an external pyro battery of up to 15V.
269 Ejection charges are wired directly to the screw terminal block
270 at the aft end of the altimeter. This is very similar to what
271 most other altimeter vendors provide and so may be the most
272 familiar option. You'll need a very small straight blade
273 screwdriver to connect and disconnect the board in this case,
274 such as you might find in a jeweler's screwdriver set.
277 TeleMetrum also uses the screw terminal block for the power
278 switch leads. On TeleMini, the power switch leads are soldered
279 directly to the board and can be connected directly to the switch.
282 For most air-frames, the integrated antennas are more than
283 adequate However, if you are installing in a carbon-fiber
284 electronics bay which is opaque to RF signals, you may need to
285 use off-board external antennas instead. In this case, you can
286 order an altimeter with an SMA connector for the UHF antenna
287 connection, and, on TeleMetrum, you can unplug the integrated GPS
288 antenna and select an appropriate off-board GPS antenna with
289 cable terminating in a U.FL connector.
293 <title>System Operation</title>
295 <title>Firmware Modes </title>
297 The AltOS firmware build for the altimeters has two
298 fundamental modes, "idle" and "flight". Which of these modes
299 the firmware operates in is determined at start up time. For
300 TeleMetrum, the mode is controlled by the orientation of the
301 rocket (well, actually the board, of course...) at the time
302 power is switched on. If the rocket is "nose up", then
303 TeleMetrum assumes it's on a rail or rod being prepared for
304 launch, so the firmware chooses flight mode. However, if the
305 rocket is more or less horizontal, the firmware instead enters
306 idle mode. For TeleMini, "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 tests, and decides which
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 In idle mode, you will hear an audible "di-dit" or see two short flashes ("I" for idle), and
334 the normal flight state machine is disengaged, thus
335 no ejection charges will fire. The altimeters also listen on the RF
336 link when in idle mode for packet mode requests sent from TeleDongle.
337 Commands can be issued to a TeleMetrum in idle mode over either
338 USB or the RF link equivalently. TeleMini uses only the RF link.
339 Idle mode is useful for configuring the altimeter, for extracting data
340 from the on-board storage chip after flight, and for ground testing
344 One "neat trick" of particular value when the altimeter is used with very
345 large air-frames, is that you can power the board up while the rocket
346 is horizontal, such that it comes up in idle mode. Then you can
347 raise the air-frame to launch position, use a TeleDongle to open
348 a packet connection, and issue a 'reset' command which will cause
349 the altimeter to reboot and come up in
350 flight mode. This is much safer than standing on the top step of a
351 rickety step-ladder or hanging off the side of a launch tower with
352 a screw-driver trying to turn on your avionics before installing
359 TeleMetrum includes a complete GPS receiver. See a later section for
360 a brief explanation of how GPS works that will help you understand
361 the information in the telemetry stream. The bottom line is that
362 the TeleMetrum GPS receiver needs to lock onto at least four
363 satellites to obtain a solid 3 dimensional position fix and know
367 TeleMetrum provides backup power to the GPS chip any time a Li-Po
368 battery is connected. This allows the receiver to "warm start" on
369 the launch rail much faster than if every power-on were a "cold start"
370 for the GPS receiver. In typical operations, powering up TeleMetrum
371 on the flight line in idle mode while performing final air-frame
372 preparation will be sufficient to allow the GPS receiver to cold
373 start and acquire lock. Then the board can be powered down during
374 RSO review and installation on a launch rod or rail. When the board
375 is turned back on, the GPS system should lock very quickly, typically
376 long before igniter installation and return to the flight line are
381 <title>Ground Testing </title>
383 An important aspect of preparing a rocket using electronic deployment
384 for flight is ground testing the recovery system. Thanks
385 to the bi-directional RF link central to the Altus Metrum system,
386 this can be accomplished in a TeleMetrum- or TeleMini- equipped rocket without as
387 much work as you may be accustomed to with other systems. It can
391 Just prep the rocket for flight, then power up the altimeter
392 in "idle" mode (placing air-frame horizontal for TeleMetrum or
393 starting the RF packet connection for TeleMini). This will cause the
394 firmware to go into "idle" mode, in which the normal flight
395 state machine is disabled and charges will not fire without
396 manual command. Then, establish an RF packet connection from
397 a TeleDongle-equipped computer using the P command from a safe
398 distance. You can now command the altimeter to fire the apogee
399 or main charges to complete your testing.
402 In order to reduce the chance of accidental firing of pyrotechnic
403 charges, the command to fire a charge is intentionally somewhat
404 difficult to type, and the built-in help is slightly cryptic to
405 prevent accidental echoing of characters from the help text back at
406 the board from firing a charge. The command to fire the apogee
407 drogue charge is 'i DoIt drogue' and the command to fire the main
408 charge is 'i DoIt main'.
412 <title>Radio Link </title>
414 The chip our boards are based on incorporates an RF transceiver, but
415 it's not a full duplex system... each end can only be transmitting or
416 receiving at any given moment. So we had to decide how to manage the
420 By design, the altimeter firmware listens for an RF connection when
421 it's in "idle mode", which
422 allows us to use the RF link to configure the rocket, do things like
423 ejection tests, and extract data after a flight without having to
424 crack open the air-frame. However, when the board is in "flight
425 mode", the altimeter only
426 transmits and doesn't listen at all. That's because we want to put
427 ultimate priority on event detection and getting telemetry out of
428 the rocket and out over
429 the RF link in case the rocket crashes and we aren't able to extract
433 We don't use a 'normal packet radio' mode because they're just too
434 inefficient. The GFSK modulation we use is just FSK with the
435 base-band pulses passed through a
436 Gaussian filter before they go into the modulator to limit the
437 transmitted bandwidth. When combined with the hardware forward error
438 correction support in the cc1111 chip, this allows us to have a very
439 robust 38.4 kilobit data link with only 10 milliwatts of transmit power,
440 a whip antenna in the rocket, and a hand-held Yagi on the ground. We've
441 had flights to above 21k feet AGL with good reception, and calculations
442 suggest we should be good to well over 40k feet AGL with a 5-element yagi on
443 the ground. We hope to fly boards to higher altitudes soon, and would
444 of course appreciate customer feedback on performance in higher
449 <title>Configurable Parameters</title>
451 Configuring an Altus Metrum altimeter for flight is very
452 simple. Through the use of a Kalman filter, there is no need
453 to set a "mach delay" . The few configurable parameters can
454 all be set using a simple terminal program over the USB port
455 or RF link via TeleDongle.
458 <title>Radio Frequencies</title>
460 The Altus Metrum boards support frequencies in the 70cm
461 band. By default, the configuration interface provides a
462 list of 10 common frequencies -- 100kHz channels starting at
463 434.550MHz. However, you can configure the firmware to use
464 any 50kHz multiple within the 70cm band. At any given
465 launch, we highly recommend coordinating who will use each
466 frequency and when to avoid interference. And of course, both
467 altimeter and TeleDongle must be configured to the same
468 frequency to successfully communicate with each other.
471 To set the radio frequency, use the 'c R' command to specify the
472 radio transceiver configuration parameter. This parameter is computed
473 using the desired frequency, 'F', the radio calibration parameter, 'C' (showed by the 'c s' command) and
474 the standard calibration reference frequency, 'S', (normally 434.550MHz):
478 Round the result to the nearest integer value.
479 As with all 'c' sub-commands, follow this with a 'c w' to write the
480 change to the parameter block in the on-board flash on
481 your altimeter board if you want the change to stay in place across reboots.
485 <title>Apogee Delay</title>
487 Apogee delay is the number of seconds after the altimeter detects flight
488 apogee that the drogue charge should be fired. In most cases, this
489 should be left at the default of 0. However, if you are flying
490 redundant electronics such as for an L3 certification, you may wish
491 to set one of your altimeters to a positive delay so that both
492 primary and backup pyrotechnic charges do not fire simultaneously.
495 To set the apogee delay, use the 'c d' command.
496 As with all 'c' sub-commands, follow this with a 'c w' to write the
497 change to the parameter block in the on-board DataFlash chip.
500 Please note that the Altus Metrum apogee detection algorithm
501 fires exactly at apogee. If you are also flying an
502 altimeter like the PerfectFlite MAWD, which only supports
503 selecting 0 or 1 seconds of apogee delay, you may wish to
504 set the MAWD to 0 seconds delay and set the TeleMetrum to
505 fire your backup 2 or 3 seconds later to avoid any chance of
506 both charges firing simultaneously. We've flown several
507 air-frames this way quite happily, including Keith's
512 <title>Main Deployment Altitude</title>
514 By default, the altimeter will fire the main deployment charge at an
515 elevation of 250 meters (about 820 feet) above ground. We think this
516 is a good elevation for most air-frames, but feel free to change this
517 to suit. In particular, if you are flying two altimeters, you may
519 deployment elevation for the backup altimeter to be something lower
520 than the primary so that both pyrotechnic charges don't fire
524 To set the main deployment altitude, use the 'c m' command.
525 As with all 'c' sub-commands, follow this with a 'c w' to write the
526 change to the parameter block in the on-board DataFlash chip.
531 <title>Calibration</title>
533 There are only two calibrations required for a TeleMetrum board, and
534 only one for TeleDongle and TeleMini.
537 <title>Radio Frequency</title>
539 The radio frequency is synthesized from a clock based on the 48 MHz
540 crystal on the board. The actual frequency of this oscillator must be
541 measured to generate a calibration constant. While our GFSK modulation
542 bandwidth is wide enough to allow boards to communicate even when
543 their oscillators are not on exactly the same frequency, performance
544 is best when they are closely matched.
545 Radio frequency calibration requires a calibrated frequency counter.
546 Fortunately, once set, the variation in frequency due to aging and
547 temperature changes is small enough that re-calibration by customers
548 should generally not be required.
551 To calibrate the radio frequency, connect the UHF antenna port to a
552 frequency counter, set the board to 434.550MHz, and use the 'C'
553 command to generate a CW carrier. Wait for the transmitter temperature
554 to stabilize and the frequency to settle down.
555 Then, divide 434.550 MHz by the
556 measured frequency and multiply by the current radio cal value show
557 in the 'c s' command. For an unprogrammed board, the default value
558 is 1186611. Take the resulting integer and program it using the 'c f'
559 command. Testing with the 'C' command again should show a carrier
560 within a few tens of Hertz of the intended frequency.
561 As with all 'c' sub-commands, follow this with a 'c w' to write the
562 change to the parameter block in the on-board DataFlash chip.
565 when the radio calibration value is changed, the radio
566 frequency value is reset to the same value, so you'll need
567 to recompute and reset the radio frequency value using the
568 new radio calibration value.
572 <title>TeleMetrum Accelerometer</title>
574 The TeleMetrum accelerometer we use has its own 5 volt power supply and
575 the output must be passed through a resistive voltage divider to match
576 the input of our 3.3 volt ADC. This means that unlike the barometric
577 sensor, the output of the acceleration sensor is not ratio-metric to
578 the ADC converter, and calibration is required. We also support the
579 use of any of several accelerometers from a Freescale family that
580 includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity,
581 a simple 2-point calibration yields acceptable results capturing both
582 the different sensitivities and ranges of the different accelerometer
583 parts and any variation in power supply voltages or resistor values
584 in the divider network.
587 To calibrate the acceleration sensor, use the 'c a 0' command. You
588 will be prompted to orient the board vertically with the UHF antenna
589 up and press a key, then to orient the board vertically with the
590 UHF antenna down and press a key.
591 As with all 'c' sub-commands, follow this with a 'c w' to write the
592 change to the parameter block in the on-board DataFlash chip.
595 The +1g and -1g calibration points are included in each telemetry
596 frame and are part of the header extracted by ao-dumplog after flight.
597 Note that we always store and return raw ADC samples for each
598 sensor... nothing is permanently "lost" or "damaged" if the
602 In the unlikely event an accel cal that goes badly, it is possible
603 that TeleMetrum may always come up in 'pad mode' and as such not be
604 listening to either the USB or radio interfaces. If that happens,
605 there is a special hook in the firmware to force the board back
606 in to 'idle mode' so you can re-do the cal. To use this hook, you
607 just need to ground the SPI clock pin at power-on. This pin is
608 available as pin 2 on the 8-pin companion connector, and pin 1 is
609 ground. So either carefully install a fine-gauge wire jumper
610 between the two pins closest to the index hole end of the 8-pin
611 connector, or plug in the programming cable to the 8-pin connector
612 and use a small screwdriver or similar to short the two pins closest
613 to the index post on the 4-pin end of the programming cable, and
614 power up the board. It should come up in 'idle mode' (two beeps).
619 <title>Updating Device Firmware</title>
621 The big conceptual thing to realize is that you have to use a
622 TeleDongle as a programmer to update a TeleMetrum or TeleMini,
623 and a TeleMetrum or other TeleDongle to program the TeleDongle
624 Due to limited memory resources in the cc1111, we don't support
625 programming directly over USB.
628 You may wish to begin by ensuring you have current firmware images.
629 These are distributed as part of the AltOS software bundle that
630 also includes the AltosUI ground station program. Newer ground
631 station versions typically work fine with older firmware versions,
632 so you don't need to update your devices just to try out new
633 software features. You can always download the most recent
634 version from <ulink url="http://www.altusmetrum.org/AltOS/"/>.
637 We recommend updating the altimeter first, before updating TeleDongle.
640 <title>Updating TeleMetrum Firmware</title>
641 <orderedlist inheritnum='inherit' numeration='arabic'>
643 Find the 'programming cable' that you got as part of the starter
644 kit, that has a red 8-pin MicroMaTch connector on one end and a
645 red 4-pin MicroMaTch connector on the other end.
648 Take the 2 screws out of the TeleDongle case to get access
649 to the circuit board.
652 Plug the 8-pin end of the programming cable to the
653 matching connector on the TeleDongle, and the 4-pin end to the
654 matching connector on the TeleMetrum.
655 Note that each MicroMaTch connector has an alignment pin that
656 goes through a hole in the PC board when you have the cable
660 Attach a battery to the TeleMetrum board.
663 Plug the TeleDongle into your computer's USB port, and power
667 Run AltosUI, and select 'Flash Image' from the File menu.
670 Pick the TeleDongle device from the list, identifying it as the
674 Select the image you want put on the TeleMetrum, which should have a
675 name in the form telemetrum-v1.1-1.0.0.ihx. It should be visible
676 in the default directory, if not you may have to poke around
677 your system to find it.
680 Make sure the configuration parameters are reasonable
681 looking. If the serial number and/or RF configuration
682 values aren't right, you'll need to change them.
685 Hit the 'OK' button and the software should proceed to flash
686 the TeleMetrum with new firmware, showing a progress bar.
689 Confirm that the TeleMetrum board seems to have updated OK, which you
690 can do by plugging in to it over USB and using a terminal program
691 to connect to the board and issue the 'v' command to check
695 If something goes wrong, give it another try.
700 <title>Updating TeleMini Firmware</title>
701 <orderedlist inheritnum='inherit' numeration='arabic'>
703 You'll need a special 'programming cable' to reprogram the
704 TeleMini. It's available on the Altus Metrum web store, or
705 you can make your own using an 8-pin MicroMaTch connector on
706 one end and a set of four pins on the other.
709 Take the 2 screws out of the TeleDongle case to get access
710 to the circuit board.
713 Plug the 8-pin end of the programming cable to the matching
714 connector on the TeleDongle, and the 4-pins into the holes
715 in the TeleMini circuit board. Note that the MicroMaTch
716 connector has an alignment pin that goes through a hole in
717 the PC board when you have the cable oriented correctly, and
718 that pin 1 on the TeleMini board is marked with a square pad
719 while the other pins have round pads.
722 Attach a battery to the TeleMini board.
725 Plug the TeleDongle into your computer's USB port, and power
729 Run AltosUI, and select 'Flash Image' from the File menu.
732 Pick the TeleDongle device from the list, identifying it as the
736 Select the image you want put on the TeleMini, which should have a
737 name in the form telemini-v1.0-1.0.0.ihx. It should be visible
738 in the default directory, if not you may have to poke around
739 your system to find it.
742 Make sure the configuration parameters are reasonable
743 looking. If the serial number and/or RF configuration
744 values aren't right, you'll need to change them.
747 Hit the 'OK' button and the software should proceed to flash
748 the TeleMini with new firmware, showing a progress bar.
751 Confirm that the TeleMini board seems to have updated OK, which you
752 can do by configuring it over the RF link through the TeleDongle, or
753 letting it come up in "flight" mode and listening for telemetry.
756 If something goes wrong, give it another try.
761 <title>Updating TeleDongle Firmware</title>
763 Updating TeleDongle's firmware is just like updating TeleMetrum or TeleMini
764 firmware, but you use either a TeleMetrum or another TeleDongle as the programmer.
766 <orderedlist inheritnum='inherit' numeration='arabic'>
768 Find the 'programming cable' that you got as part of the starter
769 kit, that has a red 8-pin MicroMaTch connector on one end and a
770 red 4-pin MicroMaTch connector on the other end.
773 Find the USB cable that you got as part of the starter kit, and
774 plug the "mini" end in to the mating connector on TeleMetrum or TeleDongle.
777 Take the 2 screws out of the TeleDongle case to get access
778 to the circuit board.
781 Plug the 8-pin end of the programming cable to the
782 matching connector on the programmer, and the 4-pin end to the
783 matching connector on the TeleDongle.
784 Note that each MicroMaTch connector has an alignment pin that
785 goes through a hole in the PC board when you have the cable
789 Attach a battery to the TeleMetrum board if you're using one.
792 Plug both the programmer and the TeleDongle into your computer's USB
793 ports, and power up the programmer.
796 Run AltosUI, and select 'Flash Image' from the File menu.
799 Pick the programmer device from the list, identifying it as the
803 Select the image you want put on the TeleDongle, which should have a
804 name in the form teledongle-v0.2-1.0.0.ihx. It should be visible
805 in the default directory, if not you may have to poke around
806 your system to find it.
809 Make sure the configuration parameters are reasonable
810 looking. If the serial number and/or RF configuration
811 values aren't right, you'll need to change them. The TeleDongle
812 serial number is on the "bottom" of the circuit board, and can
813 usually be read through the translucent blue plastic case without
814 needing to remove the board from the case.
817 Hit the 'OK' button and the software should proceed to flash
818 the TeleDongle with new firmware, showing a progress bar.
821 Confirm that the TeleDongle board seems to have updated OK, which you
822 can do by plugging in to it over USB and using a terminal program
823 to connect to the board and issue the 'v' command to check
824 the version, etc. Once you're happy, remove the programming cable
825 and put the cover back on the TeleDongle.
828 If something goes wrong, give it another try.
832 Be careful removing the programming cable from the locking 8-pin
833 connector on TeleMetrum. You'll need a fingernail or perhaps a thin
834 screwdriver or knife blade to gently pry the locking ears out
835 slightly to extract the connector. We used a locking connector on
836 TeleMetrum to help ensure that the cabling to companion boards
837 used in a rocket don't ever come loose accidentally in flight.
845 <title>AltosUI</title>
847 The AltosUI program provides a graphical user interface for
848 interacting with the Altus Metrum product family, including
849 TeleMetrum, TeleMini and TeleDongle. AltosUI can monitor telemetry data,
850 configure TeleMetrum, TeleMini and TeleDongle devices and many other
851 tasks. The primary interface window provides a selection of
852 buttons, one for each major activity in the system. This manual
853 is split into chapters, each of which documents one of the tasks
854 provided from the top-level toolbar.
857 <title>Monitor Flight</title>
858 <subtitle>Receive, Record and Display Telemetry Data</subtitle>
860 Selecting this item brings up a dialog box listing all of the
861 connected TeleDongle devices. When you choose one of these,
862 AltosUI will create a window to display telemetry data as
863 received by the selected TeleDongle device.
866 All telemetry data received are automatically recorded in
867 suitable log files. The name of the files includes the current
868 date and rocket serial and flight numbers.
871 The radio frequency being monitored by the TeleDongle device is
872 displayed at the top of the window. You can configure the
873 frequency by clicking on the frequency box and selecting the desired
874 frequency. AltosUI remembers the last frequency selected for each
875 TeleDongle and selects that automatically the next time you use
879 Below the TeleDongle frequency selector, the window contains a few
880 significant pieces of information about the altimeter providing
881 the telemetry data stream:
885 <para>The configured call-sign</para>
888 <para>The device serial number</para>
891 <para>The flight number. Each altimeter remembers how many
897 The rocket flight state. Each flight passes through several
898 states including Pad, Boost, Fast, Coast, Drogue, Main and
904 The Received Signal Strength Indicator value. This lets
905 you know how strong a signal TeleDongle is receiving. The
906 radio inside TeleDongle operates down to about -99dBm;
907 weaker signals may not be receivable. The packet link uses
908 error correction and detection techniques which prevent
909 incorrect data from being reported.
914 Finally, the largest portion of the window contains a set of
915 tabs, each of which contain some information about the rocket.
916 They're arranged in 'flight order' so that as the flight
917 progresses, the selected tab automatically switches to display
918 data relevant to the current state of the flight. You can select
919 other tabs at any time. The final 'table' tab contains all of
920 the telemetry data in one place.
923 <title>Launch Pad</title>
925 The 'Launch Pad' tab shows information used to decide when the
926 rocket is ready for flight. The first elements include red/green
927 indicators, if any of these is red, you'll want to evaluate
928 whether the rocket is ready to launch:
932 Battery Voltage. This indicates whether the Li-Po battery
933 powering the TeleMetrum has sufficient charge to last for
934 the duration of the flight. A value of more than
935 3.7V is required for a 'GO' status.
940 Apogee Igniter Voltage. This indicates whether the apogee
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 Main Igniter Voltage. This indicates whether the main
950 igniter has continuity. If the igniter has a low
951 resistance, then the voltage measured here will be close
952 to the Li-Po battery voltage. A value greater than 3.2V is
953 required for a 'GO' status.
958 On-board Data Logging. This indicates whether there is
959 space remaining on-board to store flight data for the
960 upcoming flight. If you've downloaded data, but failed
961 to erase flights, there may not be any space
962 left. TeleMetrum can store multiple flights, depending
963 on the configured maximum flight log size. TeleMini
964 stores only a single flight, so it will need to be
965 downloaded and erased after each flight to capture
966 data. This only affects on-board flight logging; the
967 altimeter will still transmit telemetry and fire
968 ejection charges at the proper times.
973 GPS Locked. For a TeleMetrum device, this indicates whether the GPS receiver is
974 currently able to compute position information. GPS requires
975 at least 4 satellites to compute an accurate position.
980 GPS Ready. For a TeleMetrum device, this indicates whether GPS has reported at least
981 10 consecutive positions without losing lock. This ensures
982 that the GPS receiver has reliable reception from the
988 The Launchpad tab also shows the computed launch pad position
989 and altitude, averaging many reported positions to improve the
995 <title>Ascent</title>
997 This tab is shown during Boost, Fast and Coast
998 phases. The information displayed here helps monitor the
999 rocket as it heads towards apogee.
1002 The height, speed and acceleration are shown along with the
1003 maximum values for each of them. This allows you to quickly
1004 answer the most commonly asked questions you'll hear during
1008 The current latitude and longitude reported by the TeleMetrum GPS are
1009 also shown. Note that under high acceleration, these values
1010 may not get updated as the GPS receiver loses position
1011 fix. Once the rocket starts coasting, the receiver should
1012 start reporting position again.
1015 Finally, the current igniter voltages are reported as in the
1016 Launch Pad tab. This can help diagnose deployment failures
1017 caused by wiring which comes loose under high acceleration.
1021 <title>Descent</title>
1023 Once the rocket has reached apogee and (we hope) activated the
1024 apogee charge, attention switches to tracking the rocket on
1025 the way back to the ground, and for dual-deploy flights,
1026 waiting for the main charge to fire.
1029 To monitor whether the apogee charge operated correctly, the
1030 current descent rate is reported along with the current
1031 height. Good descent rates generally range from 15-30m/s.
1034 For TeleMetrum altimeters, you can locate the rocket in the sky
1035 using the elevation and
1036 bearing information to figure out where to look. Elevation is
1037 in degrees above the horizon. Bearing is reported in degrees
1038 relative to true north. Range can help figure out how big the
1039 rocket will appear. Note that all of these values are relative
1040 to the pad location. If the elevation is near 90°, the rocket
1041 is over the pad, not over you.
1044 Finally, the igniter voltages are reported in this tab as
1045 well, both to monitor the main charge as well as to see what
1046 the status of the apogee charge is.
1050 <title>Landed</title>
1052 Once the rocket is on the ground, attention switches to
1053 recovery. While the radio signal is generally lost once the
1054 rocket is on the ground, the last reported GPS position is
1055 generally within a short distance of the actual landing location.
1058 The last reported GPS position is reported both by
1059 latitude and longitude as well as a bearing and distance from
1060 the launch pad. The distance should give you a good idea of
1061 whether you'll want to walk or hitch a ride. Take the reported
1062 latitude and longitude and enter them into your hand-held GPS
1063 unit and have that compute a track to the landing location.
1066 Both TeleMini and TeleMetrum will continue to transmit RDF
1067 tones after landing, allowing you to locate the rocket by
1068 following the radio signal. You may need to get away from
1069 the clutter of the flight line, or even get up on a hill (or
1070 your neighbor's RV) to receive the RDF signal.
1073 The maximum height, speed and acceleration reported
1074 during the flight are displayed for your admiring observers.
1077 To get more detailed information about the flight, you can
1078 click on the 'Graph Flight' button which will bring up a
1079 graph window for the current flight.
1083 <title>Site Map</title>
1085 When the TeleMetrum gets a GPS fix, the Site Map tab will map
1086 the rocket's position to make it easier for you to locate the
1087 rocket, both while it is in the air, and when it has landed. The
1088 rocket's state is indicated by color: white for pad, red for
1089 boost, pink for fast, yellow for coast, light blue for drogue,
1090 dark blue for main, and black for landed.
1093 The map's scale is approximately 3m (10ft) per pixel. The map
1094 can be dragged using the left mouse button. The map will attempt
1095 to keep the rocket roughly centered while data is being received.
1098 Images are fetched automatically via the Google Maps Static API,
1099 and are cached for reuse. If map images cannot be downloaded,
1100 the rocket's path will be traced on a dark gray background
1104 You can pre-load images for your favorite launch sites
1105 before you leave home; check out the 'Preload Maps' section below.
1110 <title>Packet Command Mode</title>
1111 <subtitle>Controlling An Altimeter Over The Radio Link</subtitle>
1113 One of the unique features of the Altus Metrum environment is
1114 the ability to create a two way command link between TeleDongle
1115 and an altimeter using the digital radio transceivers built into
1116 each device. This allows you to interact with the altimeter from
1117 afar, as if it were directly connected to the computer.
1120 Any operation which can be performed with TeleMetrum
1121 can either be done with TeleMetrum directly connected to
1122 the computer via the USB cable, or through the packet
1123 link. Simply select the appropriate TeleDongle device when
1124 the list of devices is presented and AltosUI will use packet
1128 One oddity in the current interface is how AltosUI selects the
1129 frequency for packet mode communications. Instead of providing
1130 an interface to specifically configure the frequency, it uses
1131 whatever frequency was most recently selected for the target
1132 TeleDongle device in Monitor Flight mode. If you haven't ever
1133 used that mode with the TeleDongle in question, select the
1134 Monitor Flight button from the top level UI, pick the
1135 appropriate TeleDongle device. Once the flight monitoring
1136 window is open, select the desired frequency and then close it
1137 down again. All Packet Command Mode operations will now use
1143 Save Flight Data—Recover flight data from the rocket without
1149 Configure altimeter apogee delays or main deploy heights
1150 to respond to changing launch conditions. You can also
1151 'reboot' the altimeter. Use this to remotely enable the
1152 flight computer by turning TeleMetrum on in "idle" mode,
1153 then once the air-frame is oriented for launch, you can
1154 reboot the altimeter and have it restart in pad mode
1155 without having to climb the scary ladder.
1160 Fire Igniters—Test your deployment charges without snaking
1161 wires out through holes in the air-frame. Simply assembly the
1162 rocket as if for flight with the apogee and main charges
1163 loaded, then remotely command the altimeter to fire the
1169 Packet command mode uses the same RF frequencies as telemetry
1170 mode. Configure the desired TeleDongle frequency using the
1171 flight monitor window frequency selector and then close that
1172 window before performing the desired operation.
1175 TeleMetrum only enables packet command mode in 'idle' mode, so
1176 make sure you have TeleMetrum lying horizontally when you turn
1177 it on. Otherwise, TeleMetrum will start in 'pad' mode ready for
1178 flight and will not be listening for command packets from TeleDongle.
1181 TeleMini listens for a command packet for five seconds after
1182 first being turned on, if it doesn't hear anything, it enters
1183 'pad' mode, ready for flight and will no longer listen for
1187 When packet command mode is enabled, you can monitor the link
1188 by watching the lights on the
1189 devices. The red LED will flash each time they
1190 transmit a packet while the green LED will light up
1191 on TeleDongle while it is waiting to receive a packet from
1196 <title>Save Flight Data</title>
1198 The altimeter records flight data to its internal flash memory.
1199 The TeleMetrum data is recorded at a much higher rate than the telemetry
1200 system can handle, and is not subject to radio drop-outs. As
1201 such, it provides a more complete and precise record of the
1202 flight. The 'Save Flight Data' button allows you to read the
1203 flash memory and write it to disk. As TeleMini has only a barometer, it
1204 records data at the same rate as the telemetry signal, but there will be
1205 no data lost due to telemetry drop-outs.
1208 Clicking on the 'Save Flight Data' button brings up a list of
1209 connected TeleMetrum and TeleDongle devices. If you select a
1210 TeleMetrum device, the flight data will be downloaded from that
1211 device directly. If you select a TeleDongle device, flight data
1212 will be downloaded from a TeleMetrum or TeleMini device connected via the
1213 packet command link to the specified TeleDongle. See the chapter
1214 on Packet Command Mode for more information about this.
1217 After the device has been selected, a dialog showing the
1218 flight data saved in the device will be shown allowing you to
1219 select which flights to download and which to delete. With
1220 version 0.9 or newer firmware, you must erase flights in order
1221 for the space they consume to be reused by another
1222 flight. This prevents you from accidentally losing flight data
1223 if you neglect to download data before flying again. Note that
1224 if there is no more space available in the device, then no
1225 data will be recorded for a flight.
1228 The file name for each flight log is computed automatically
1229 from the recorded flight date, altimeter serial number and
1230 flight number information.
1234 <title>Replay Flight</title>
1236 Select this button and you are prompted to select a flight
1237 record file, either a .telem file recording telemetry data or a
1238 .eeprom file containing flight data saved from the altimeter
1242 Once a flight record is selected, the flight monitor interface
1243 is displayed and the flight is re-enacted in real time. Check
1244 the Monitor Flight chapter above to learn how this window operates.
1248 <title>Graph Data</title>
1250 Select this button and you are prompted to select a flight
1251 record file, either a .telem file recording telemetry data or a
1252 .eeprom file containing flight data saved from
1256 Once a flight record is selected, a window with two tabs is
1257 opened. The first tab contains a graph with acceleration
1258 (blue), velocity (green) and altitude (red) of the flight are
1259 plotted and displayed, measured in metric units. The
1260 apogee(yellow) and main(magenta) igniter voltages are also
1261 displayed; high voltages indicate continuity, low voltages
1262 indicate open circuits. The second tab contains some basic
1266 The graph can be zoomed into a particular area by clicking and
1267 dragging down and to the right. Once zoomed, the graph can be
1268 reset by clicking and dragging up and to the left. Holding down
1269 control and clicking and dragging allows the graph to be panned.
1270 The right mouse button causes a pop-up menu to be displayed, giving
1271 you the option save or print the plot.
1274 Note that telemetry files will generally produce poor graphs
1275 due to the lower sampling rate and missed telemetry packets.
1276 Use saved flight data for graphing where possible.
1280 <title>Export Data</title>
1282 This tool takes the raw data files and makes them available for
1283 external analysis. When you select this button, you are prompted to select a flight
1284 data file (either .eeprom or .telem will do, remember that
1285 .eeprom files contain higher resolution and more continuous
1286 data). Next, a second dialog appears which is used to select
1287 where to write the resulting file. It has a selector to choose
1288 between CSV and KML file formats.
1291 <title>Comma Separated Value Format</title>
1293 This is a text file containing the data in a form suitable for
1294 import into a spreadsheet or other external data analysis
1295 tool. The first few lines of the file contain the version and
1296 configuration information from the altimeter, then
1297 there is a single header line which labels all of the
1298 fields. All of these lines start with a '#' character which
1299 most tools can be configured to skip over.
1302 The remaining lines of the file contain the data, with each
1303 field separated by a comma and at least one space. All of
1304 the sensor values are converted to standard units, with the
1305 barometric data reported in both pressure, altitude and
1306 height above pad units.
1310 <title>Keyhole Markup Language (for Google Earth)</title>
1312 This is the format used by
1313 Googleearth to provide an overlay within that
1314 application. With this, you can use Googleearth to see the
1315 whole flight path in 3D.
1320 <title>Configure Altimeter</title>
1322 Select this button and then select either a TeleMetrum or
1323 TeleDongle Device from the list provided. Selecting a TeleDongle
1324 device will use Packet Command Mode to configure a remote
1325 altimeter. Learn how to use this in the Packet Command
1329 The first few lines of the dialog provide information about the
1330 connected device, including the product name,
1331 software version and hardware serial number. Below that are the
1332 individual configuration entries.
1335 At the bottom of the dialog, there are four buttons:
1340 Save. This writes any changes to the
1341 configuration parameter block in flash memory. If you don't
1342 press this button, any changes you make will be lost.
1347 Reset. This resets the dialog to the most recently saved values,
1348 erasing any changes you have made.
1353 Reboot. This reboots the device. Use this to
1354 switch from idle to pad mode by rebooting once the rocket is
1355 oriented for flight.
1360 Close. This closes the dialog. Any unsaved changes will be
1366 The rest of the dialog contains the parameters to be configured.
1369 <title>Main Deploy Altitude</title>
1371 This sets the altitude (above the recorded pad altitude) at
1372 which the 'main' igniter will fire. The drop-down menu shows
1373 some common values, but you can edit the text directly and
1374 choose whatever you like. If the apogee charge fires below
1375 this altitude, then the main charge will fire two seconds
1376 after the apogee charge fires.
1380 <title>Apogee Delay</title>
1382 When flying redundant electronics, it's often important to
1383 ensure that multiple apogee charges don't fire at precisely
1384 the same time as that can over pressurize the apogee deployment
1385 bay and cause a structural failure of the air-frame. The Apogee
1386 Delay parameter tells the flight computer to fire the apogee
1387 charge a certain number of seconds after apogee has been
1392 <title>Radio Frequency</title>
1394 This configures which of the configured frequencies to use for both
1395 telemetry and packet command mode. Note that if you set this
1396 value via packet command mode, you will have to reconfigure
1397 the TeleDongle frequency before you will be able to use packet
1402 <title>Radio Calibration</title>
1404 The radios in every Altus Metrum device are calibrated at the
1405 factory to ensure that they transmit and receive on the
1406 specified frequency. You can adjust that
1407 calibration by changing this value. To change the TeleDongle's
1408 calibration, you must reprogram the unit completely.
1412 <title>Callsign</title>
1414 This sets the call sign included in each telemetry packet. Set this
1415 as needed to conform to your local radio regulations.
1419 <title>Maximum Flight Log Size</title>
1421 This sets the space (in kilobytes) allocated for each flight
1422 log. The available space will be divided into chunks of this
1423 size. A smaller value will allow more flights to be stored,
1424 a larger value will record data from longer flights.
1427 During ascent, TeleMetrum records barometer and
1428 accelerometer values 100 times per second, other analog
1429 information (voltages and temperature) 6 times per second
1430 and GPS data once per second. During descent, the non-GPS
1431 data is recorded 1/10th as often. Each barometer +
1432 accelerometer record takes 8 bytes.
1435 The default, 192kB, will store over 200 seconds of data at
1436 the ascent rate, or over 2000 seconds of data at the descent
1437 rate. That's plenty for most flights. This leaves enough
1438 storage for five flights in a 1MB system, or 10 flights in a
1442 The configuration block takes the last available block of
1443 memory, on v1.0 boards that's just 256 bytes. However, the
1444 flash part on the v1.1 boards uses 64kB for each block.
1447 TeleMini has 5kB of on-board storage, which is plenty for a
1448 single flight. Make sure you download and delete the data
1449 before a subsequent flight or it will not log any data.
1453 <title>Ignite Mode</title>
1455 TeleMetrum and TeleMini provide two igniter channels as they
1456 were originally designed as dual-deploy flight
1457 computers. This configuration parameter allows the two
1458 channels to be used in different configurations.
1463 Dual Deploy. This is the usual mode of operation; the
1464 'apogee' channel is fired at apogee and the 'main'
1465 channel at the height above ground specified by the
1466 'Main Deploy Altitude' during descent.
1471 Redundant Apogee. This fires both channels at
1472 apogee, the 'apogee' channel first followed after a two second
1473 delay by the 'main' channel.
1478 Redundant Main. This fires both channels at the
1479 height above ground specified by the Main Deploy
1480 Altitude setting during descent. The 'apogee'
1481 channel is fired first, followed after a two second
1482 delay by the 'main' channel.
1488 <title>Pad Orientation</title>
1490 Because it includes an accelerometer, TeleMetrum is
1491 sensitive to the orientation of the board. By default, it
1492 expects the antenna end to point forward. This parameter
1493 allows that default to be changed, permitting the board to
1494 be mounted with the antenna pointing aft instead.
1499 Antenna Up. In this mode, the antenna end of the
1500 TeleMetrum board must point forward, in line with the
1501 expected flight path.
1506 Antenna Down. In this mode, the antenna end of the
1507 TeleMetrum board must point aft, in line with the
1508 expected flight path.
1515 <title>Configure AltosUI</title>
1517 This button presents a dialog so that you can configure the AltosUI global settings.
1520 <title>Voice Settings</title>
1522 AltosUI provides voice announcements during flight so that you
1523 can keep your eyes on the sky and still get information about
1524 the current flight status. However, sometimes you don't want
1529 <para>Enable—turns all voice announcements on and off</para>
1533 Test Voice—Plays a short message allowing you to verify
1534 that the audio system is working and the volume settings
1541 <title>Log Directory</title>
1543 AltosUI logs all telemetry data and saves all TeleMetrum flash
1544 data to this directory. This directory is also used as the
1545 staring point when selecting data files for display or export.
1548 Click on the directory name to bring up a directory choosing
1549 dialog, select a new directory and click 'Select Directory' to
1550 change where AltosUI reads and writes data files.
1554 <title>Callsign</title>
1556 This value is used in command packet mode and is transmitted
1557 in each packet sent from TeleDongle and received from
1558 TeleMetrum. It is not used in telemetry mode as that transmits
1559 packets only from TeleMetrum to TeleDongle. Configure this
1560 with the AltosUI operators call sign as needed to comply with
1561 your local radio regulations.
1565 <title>Font Size</title>
1567 Selects the set of fonts used in the flight monitor
1568 window. Choose between the small, medium and large sets.
1572 <title>Serial Debug</title>
1574 This causes all communication with a connected device to be
1575 dumped to the console from which AltosUI was started. If
1576 you've started it from an icon or menu entry, the output
1577 will simply be discarded. This mode can be useful to debug
1578 various serial communication issues.
1582 <title>Manage Frequencies</title>
1584 This brings up a dialog where you can configure the set of
1585 frequencies shown in the various frequency menus. You can
1586 add as many as you like, or even reconfigure the default
1587 set. Changing this list does not affect the frequency
1588 settings of any devices, it only changes the set of
1589 frequencies shown in the menus.
1594 <title>Flash Image</title>
1596 This reprograms any Altus Metrum device by using a TeleMetrum
1597 or TeleDongle as a programming dongle. Please read the
1598 directions for flashing devices in the Updating Device
1599 Firmware section above
1602 Once you have the programmer and target devices connected,
1603 push the 'Flash Image' button. That will present a dialog box
1604 listing all of the connected devices. Carefully select the
1605 programmer device, not the device to be programmed.
1608 Next, select the image to flash to the device. These are named
1609 with the product name and firmware version. The file selector
1610 will start in the directory containing the firmware included
1611 with the AltosUI package. Navigate to the directory containing
1612 the desired firmware if it isn't there.
1615 Next, a small dialog containing the device serial number and
1616 RF calibration values should appear. If these values are
1617 incorrect (possibly due to a corrupted image in the device),
1618 enter the correct values here.
1621 Finally, a dialog containing a progress bar will follow the
1622 programming process.
1625 When programming is complete, the target device will
1626 reboot. Note that if the target device is connected via USB, you
1627 will have to unplug it and then plug it back in for the USB
1628 connection to reset so that you can communicate with the device
1633 <title>Fire Igniter</title>
1635 This activates the igniter circuits in TeleMetrum to help test
1636 recovery systems deployment. Because this command can operate
1637 over the Packet Command Link, you can prepare the rocket as
1638 for flight and then test the recovery system without needing
1639 to snake wires inside the air-frame.
1642 Selecting the 'Fire Igniter' button brings up the usual device
1643 selection dialog. Pick the desired TeleDongle or TeleMetrum
1644 device. This brings up another window which shows the current
1645 continuity test status for both apogee and main charges.
1648 Next, select the desired igniter to fire. This will enable the
1652 Select the 'Arm' button. This enables the 'Fire' button. The
1653 word 'Arm' is replaced by a countdown timer indicating that
1654 you have 10 seconds to press the 'Fire' button or the system
1655 will deactivate, at which point you start over again at
1656 selecting the desired igniter.
1660 <title>Scan Channels</title>
1662 This listens for telemetry packets on all of the configured
1663 frequencies, displaying information about each device it
1664 receives a packet from. You can select which of the three
1665 telemetry formats should be tried; by default, it only listens
1666 for the standard telemetry packets used in v1.0 and later
1671 <title>Load Maps</title>
1673 Before heading out to a new launch site, you can use this to
1674 load satellite images in case you don't have internet
1675 connectivity at the site. This loads a fairly large area
1676 around the launch site, which should cover any flight you're likely to make.
1679 There's a drop-down menu of launch sites we know about; if
1680 your favorites aren't there, please let us know the lat/lon
1681 and name of the site. The contents of this list are actually
1682 downloaded at run-time, so as new sites are sent in, they'll
1683 get automatically added to this list.
1686 If the launch site isn't in the list, you can manually enter the lat/lon values
1689 Clicking the 'Load Map' button will fetch images from Google
1690 Maps; note that Google limits how many images you can fetch at
1691 once, so if you load more than one launch site, you may get
1692 some gray areas in the map which indicate that Google is tired
1693 of sending data to you. Try again later.
1697 <title>Monitor Idle</title>
1699 This brings up a dialog similar to the Monitor Flight UI,
1700 except it works with the altimeter in "idle" mode by sending
1701 query commands to discover the current state rather than
1702 listening for telemetry packets.
1707 <title>Using Altus Metrum Products</title>
1709 <title>Being Legal</title>
1711 First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
1712 other authorization to legally operate the radio transmitters that are part
1717 <title>In the Rocket</title>
1719 In the rocket itself, you just need a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> or
1720 <ulink url="http://www.altusmetrum.org/TeleMini/">TeleMini</ulink> board and
1721 a Li-Po rechargeable battery. An 860mAh battery weighs less than a 9V
1722 alkaline battery, and will run a TeleMetrum for hours.
1723 A 110mAh battery weighs less than a triple A battery and will run a TeleMetrum for
1724 a few hours, or a TeleMini for much (much) longer.
1727 By default, we ship the altimeters with a simple wire antenna. If your
1728 electronics bay or the air-frame it resides within is made of carbon fiber,
1729 which is opaque to RF signals, you may choose to have an SMA connector
1730 installed so that you can run a coaxial cable to an antenna mounted
1731 elsewhere in the rocket.
1735 <title>On the Ground</title>
1737 To receive the data stream from the rocket, you need an antenna and short
1738 feed-line connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> units. The
1739 TeleDongle in turn plugs directly into the USB port on a notebook
1740 computer. Because TeleDongle looks like a simple serial port, your computer
1741 does not require special device drivers... just plug it in.
1744 The GUI tool, AltosUI, is written in Java and runs across
1745 Linux, Mac OS and Windows. There's also a suite of C tools
1746 for Linux which can perform most of the same tasks.
1749 After the flight, you can use the RF link to extract the more detailed data
1750 logged in either TeleMetrum or TeleMini devices, or you can use a mini USB cable to plug into the
1751 TeleMetrum board directly. Pulling out the data without having to open up
1752 the rocket is pretty cool! A USB cable is also how you charge the Li-Po
1753 battery, so you'll want one of those anyway... the same cable used by lots
1754 of digital cameras and other modern electronic stuff will work fine.
1757 If your TeleMetrum-equipped rocket lands out of sight, you may enjoy having a hand-held GPS
1758 receiver, so that you can put in a way-point for the last reported rocket
1759 position before touch-down. This makes looking for your rocket a lot like
1760 Geo-Caching... just go to the way-point and look around starting from there.
1763 You may also enjoy having a ham radio "HT" that covers the 70cm band... you
1764 can use that with your antenna to direction-find the rocket on the ground
1765 the same way you can use a Walston or Beeline tracker. This can be handy
1766 if the rocket is hiding in sage brush or a tree, or if the last GPS position
1767 doesn't get you close enough because the rocket dropped into a canyon, or
1768 the wind is blowing it across a dry lake bed, or something like that... Keith
1769 and Bdale both currently own and use the Yaesu VX-7R at launches.
1772 So, to recap, on the ground the hardware you'll need includes:
1773 <orderedlist inheritnum='inherit' numeration='arabic'>
1775 an antenna and feed-line
1784 optionally, a hand-held GPS receiver
1787 optionally, an HT or receiver covering 435 MHz
1792 The best hand-held commercial directional antennas we've found for radio
1793 direction finding rockets are from
1794 <ulink url="http://www.arrowantennas.com/" >
1797 The 440-3 and 440-5 are both good choices for finding a
1798 TeleMetrum- or TeleMini- equipped rocket when used with a suitable 70cm HT.
1802 <title>Data Analysis</title>
1804 Our software makes it easy to log the data from each flight, both the
1805 telemetry received over the RF link during the flight itself, and the more
1806 complete data log recorded in the flash memory on the altimeter
1807 board. Once this data is on your computer, our post-flight tools make it
1808 easy to quickly get to the numbers everyone wants, like apogee altitude,
1809 max acceleration, and max velocity. You can also generate and view a
1810 standard set of plots showing the altitude, acceleration, and
1811 velocity of the rocket during flight. And you can even export a TeleMetrum data file
1812 usable with Google Maps and Google Earth for visualizing the flight path
1813 in two or three dimensions!
1816 Our ultimate goal is to emit a set of files for each flight that can be
1817 published as a web page per flight, or just viewed on your local disk with
1822 <title>Future Plans</title>
1824 In the future, we intend to offer "companion boards" for the rocket that will
1825 plug in to TeleMetrum to collect additional data, provide more pyro channels,
1826 and so forth. A reference design for a companion board will be documented
1827 soon, and will be compatible with open source Arduino programming tools.
1830 We are also working on the design of a hand-held ground terminal that will
1831 allow monitoring the rocket's status, collecting data during flight, and
1832 logging data after flight without the need for a notebook computer on the
1833 flight line. Particularly since it is so difficult to read most notebook
1834 screens in direct sunlight, we think this will be a great thing to have.
1837 Because all of our work is open, both the hardware designs and the software,
1838 if you have some great idea for an addition to the current Altus Metrum family,
1839 feel free to dive in and help! Or let us know what you'd like to see that
1840 we aren't already working on, and maybe we'll get excited about it too...
1845 <title>Altimeter Installation Recommendations</title>
1847 Building high-power rockets that fly safely is hard enough. Mix
1848 in some sophisticated electronics and a bunch of radio energy
1849 and oftentimes you find few perfect solutions. This chapter
1850 contains some suggestions about how to install Altus Metrum
1851 products into the rocket air-frame, including how to safely and
1852 reliably mix a variety of electronics into the same air-frame.
1855 <title>Mounting the Altimeter</title>
1857 The first consideration is to ensure that the altimeter is
1858 securely fastened to the air-frame. For TeleMetrum, we use
1859 nylon standoffs and nylon screws; they're good to at least 50G
1860 and cannot cause any electrical issues on the board. For
1861 TeleMini, we usually cut small pieces of 1/16" balsa to fit
1862 under the screw holes, and then take 2x56 nylon screws and
1863 screw them through the TeleMini mounting holes, through the
1864 balsa and into the underlying material.
1866 <orderedlist inheritnum='inherit' numeration='arabic'>
1868 Make sure TeleMetrum is aligned precisely along the axis of
1869 acceleration so that the accelerometer can accurately
1870 capture data during the flight.
1873 Watch for any metal touching components on the
1874 board. Shorting out connections on the bottom of the board
1875 can cause the altimeter to fail during flight.
1880 <title>Dealing with the Antenna</title>
1882 The antenna supplied is just a piece of solid, insulated,
1883 wire. If it gets damaged or broken, it can be easily
1884 replaced. It should be kept straight and not cut; bending or
1885 cutting it will change the resonant frequency and/or
1886 impedance, making it a less efficient radiator and thus
1887 reducing the range of the telemetry signal.
1890 Keeping metal away from the antenna will provide better range
1891 and a more even radiation pattern. In most rockets, it's not
1892 entirely possible to isolate the antenna from metal
1893 components; there are often bolts, all-thread and wires from other
1894 electronics to contend with. Just be aware that the more stuff
1895 like this around the antenna, the lower the range.
1898 Make sure the antenna is not inside a tube made or covered
1899 with conducting material. Carbon fiber is the most common
1900 culprit here -- CF is a good conductor and will effectively
1901 shield the antenna, dramatically reducing signal strength and
1902 range. Metallic flake paint is another effective shielding
1903 material which is to be avoided around any antennas.
1906 If the ebay is large enough, it can be convenient to simply
1907 mount the altimeter at one end and stretch the antenna out
1908 inside. Taping the antenna to the sled can keep it straight
1909 under acceleration. If there are metal rods, keep the
1910 antenna as far away as possible.
1913 For a shorter ebay, it's quite practical to have the antenna
1914 run through a bulkhead and into an adjacent bay. Drill a small
1915 hole in the bulkhead, pass the antenna wire through it and
1916 then seal it up with glue or clay. We've also used acrylic
1917 tubing to create a cavity for the antenna wire. This works a
1918 bit better in that the antenna is known to stay straight and
1919 not get folded by recovery components in the bay. Angle the
1920 tubing towards the side wall of the rocket and it ends up
1921 consuming very little space.
1924 If you need to place the antenna at a distance from the
1925 altimeter, you can replace the antenna with an edge-mounted
1926 SMA connector, and then run 50Ω coax from the board to the
1927 antenna. Building a remote antenna is beyond the scope of this
1932 <title>Preserving GPS Reception</title>
1934 The GPS antenna and receiver in TeleMetrum are highly
1935 sensitive and normally have no trouble tracking enough
1936 satellites to provide accurate position information for
1937 recovering the rocket. However, there are many ways to
1938 attenuate the GPS signal.
1939 <orderedlist inheritnum='inherit' numeration='arabic'>
1941 Conductive tubing or coatings. Carbon fiber and metal
1942 tubing, or metallic paint will all dramatically attenuate the
1943 GPS signal. We've never heard of anyone successfully
1944 receiving GPS from inside these materials.
1947 Metal components near the GPS patch antenna. These will
1948 de-tune the patch antenna, changing the resonant frequency
1949 away from the L1 carrier and reduce the effectiveness of the
1950 antenna. You can place as much stuff as you like beneath the
1951 antenna as that's covered with a ground plane. But, keep
1952 wires and metal out from above the patch antenna.
1958 <title>Radio Frequency Interference</title>
1960 Any altimeter will generate RFI; the digital circuits use
1961 high-frequency clocks that spray radio interference across a
1962 wide band. Altusmetrum altimeters generate intentional radio
1963 signals as well, increasing the amount of RF energy around the board.
1966 Rocketry altimeters also use precise sensors measuring air
1967 pressure and acceleration. Tiny changes in voltage can cause
1968 these sensor readings to vary by a huge amount. When the
1969 sensors start mis-reporting data, the altimeter can either
1970 fire the igniters at the wrong time, or not fire them at all.
1973 Voltages are induced when radio frequency energy is
1974 transmitted from one circuit to another. Here are things that
1975 increase the induced voltage and current:
1979 Keep wires from different circuits apart. Moving circuits
1980 further apart will reduce RFI.
1983 Avoid parallel wires from different circuits. The longer two
1984 wires run parallel to one another, the larger the amount of
1985 transferred energy. Cross wires at right angles to reduce
1989 Twist wires from the same circuits. Two wires the same
1990 distance from the transmitter will get the same amount of
1991 induced energy which will then cancel out. Any time you have
1992 a wire pair running together, twist the pair together to
1993 even out distances and reduce RFI. For altimeters, this
1994 includes battery leads, switch hookups and igniter
1998 Avoid resonant lengths. Know what frequencies are present
1999 in the environment and avoid having wire lengths near a
2000 natural resonant length. Altusmetrum products transmit on the
2001 70cm amateur band, so you should avoid lengths that are a
2002 simple ratio of that length; essentially any multiple of 1/4
2003 of the wavelength (17.5cm).
2008 <title>The Barometric Sensor</title>
2010 Altusmetrum altimeters measure altitude with a barometric
2011 sensor, essentially measuring the amount of air above the
2012 rocket to figure out how high it is. A large number of
2013 measurements are taken as the altimeter initializes itself to
2014 figure out the pad altitude. Subsequent measurements are then
2015 used to compute the height above the pad.
2018 To accurately measure atmospheric pressure, the ebay
2019 containing the altimeter must be vented outside the
2020 air-frame. The vent must be placed in a region of linear
2021 airflow, smooth and not in an area of increasing or decreasing
2025 The barometric sensor in the altimeter is quite sensitive to
2026 chemical damage from the products of APCP or BP combustion, so
2027 make sure the ebay is carefully sealed from any compartment
2028 which contains ejection charges or motors.
2032 <title>Ground Testing</title>
2034 The most important aspect of any installation is careful
2035 ground testing. Bringing an air-frame up to the LCO table which
2036 hasn't been ground tested can lead to delays or ejection
2037 charges firing on the pad, or, even worse, a recovery system
2041 Do a 'full systems' test that includes wiring up all igniters
2042 without any BP and turning on all of the electronics in flight
2043 mode. This will catch any mistakes in wiring and any residual
2044 RFI issues that might accidentally fire igniters at the wrong
2045 time. Let the air-frame sit for several minutes, checking for
2046 adequate telemetry signal strength and GPS lock.
2049 Ground test the ejection charges. Prepare the rocket for
2050 flight, loading ejection charges and igniters. Completely
2051 assemble the air-frame and then use the 'Fire Igniters'
2052 interface through a TeleDongle to command each charge to
2053 fire. Make sure the charge is sufficient to robustly separate
2054 the air-frame and deploy the recovery system.
2059 <title>Hardware Specifications</title>
2061 <title>TeleMetrum Specifications</title>
2065 Recording altimeter for model rocketry.
2070 Supports dual deployment (can fire 2 ejection charges).
2075 70cm ham-band transceiver for telemetry down-link.
2080 Barometric pressure sensor good to 45k feet MSL.
2085 1-axis high-g accelerometer for motor characterization, capable of
2086 +/- 50g using default part.
2091 On-board, integrated GPS receiver with 5Hz update rate capability.
2096 On-board 1 megabyte non-volatile memory for flight data storage.
2101 USB interface for battery charging, configuration, and data recovery.
2106 Fully integrated support for Li-Po rechargeable batteries.
2111 Uses Li-Po to fire e-matches, can be modified to support
2112 optional separate pyro battery if needed.
2117 2.75 x 1 inch board designed to fit inside 29mm air-frame coupler tube.
2123 <title>TeleMini Specifications</title>
2127 Recording altimeter for model rocketry.
2132 Supports dual deployment (can fire 2 ejection charges).
2137 70cm ham-band transceiver for telemetry down-link.
2142 Barometric pressure sensor good to 45k feet MSL.
2147 On-board 5 kilobyte non-volatile memory for flight data storage.
2152 RF interface for battery charging, configuration, and data recovery.
2157 Support for Li-Po rechargeable batteries, using an external charger.
2162 Uses Li-Po to fire e-matches, can be modified to support
2163 optional separate pyro battery if needed.
2168 1.5 x .5 inch board designed to fit inside 18mm air-frame coupler tube.
2177 TeleMetrum seems to shut off when disconnected from the
2178 computer. Make sure the battery is adequately charged. Remember the
2179 unit will pull more power than the USB port can deliver before the
2180 GPS enters "locked" mode. The battery charges best when TeleMetrum
2184 It's impossible to stop the TeleDongle when it's in "p" mode, I have
2185 to unplug the USB cable? Make sure you have tried to "escape out" of
2186 this mode. If this doesn't work the reboot procedure for the
2187 TeleDongle *is* to simply unplug it. 'cu' however will retain it's
2188 outgoing buffer IF your "escape out" ('~~') does not work.
2189 At this point using either 'ao-view' (or possibly
2190 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
2194 The amber LED (on the TeleMetrum) lights up when both
2195 battery and USB are connected. Does this mean it's charging?
2196 Yes, the yellow LED indicates the charging at the 'regular' rate.
2197 If the led is out but the unit is still plugged into a USB port,
2198 then the battery is being charged at a 'trickle' rate.
2201 There are no "dit-dah-dah-dit" sound or lights like the manual mentions?
2202 That's the "pad" mode. Weak batteries might be the problem.
2203 It is also possible that the TeleMetrum is horizontal and the output
2204 is instead a "dit-dit" meaning 'idle'. For TeleMini, it's possible that
2205 it received a command packet which would have left it in "pad" mode.
2208 How do I save flight data?
2209 Live telemetry is written to file(s) whenever AltosUI is connected
2210 to the TeleDongle. The file area defaults to ~/TeleMetrum
2211 but is easily changed using the menus in AltosUI. The files that
2212 are written end in '.telem'. The after-flight
2213 data-dumped files will end in .eeprom and represent continuous data
2214 unlike the RF-linked .telem files that are subject to losses
2215 along the RF data path.
2216 See the above instructions on what and how to save the eeprom stored
2217 data after physically retrieving your altimeter. Make sure to save
2218 the on-board data after each flight; while the TeleMetrum can store
2219 multiple flights, you never know when you'll lose the altimeter...
2223 <title>Notes for Older Software</title>
2226 Before AltosUI was written, using Altus Metrum devices required
2227 some finesse with the Linux command line. There was a limited
2228 GUI tool, ao-view, which provided functionality similar to the
2229 Monitor Flight window in AltosUI, but everything else was a
2230 fairly 80's experience. This appendix includes documentation for
2231 using that software.
2235 Both TeleMetrum and TeleDongle can be directly communicated
2236 with using USB ports. The first thing you should try after getting
2237 both units plugged into to your computer's USB port(s) is to run
2238 'ao-list' from a terminal-window to see what port-device-name each
2239 device has been assigned by the operating system.
2240 You will need this information to access the devices via their
2241 respective on-board firmware and data using other command line
2242 programs in the AltOS software suite.
2245 TeleMini can be communicated with through a TeleDongle device
2246 over the radio link. When first booted, TeleMini listens for a
2247 TeleDongle device and if it receives a packet, it goes into
2248 'idle' mode. Otherwise, it goes into 'pad' mode and waits to be
2249 launched. The easiest way to get it talking is to start the
2250 communication link on the TeleDongle and the power up the
2254 To access the device's firmware for configuration you need a terminal
2255 program such as you would use to talk to a modem. The software
2256 authors prefer using the program 'cu' which comes from the UUCP package
2257 on most Unix-like systems such as Linux. An example command line for
2258 cu might be 'cu -l /dev/ttyACM0', substituting the correct number
2259 indicated from running the
2260 ao-list program. Another reasonable terminal program for Linux is
2261 'cutecom'. The default 'escape'
2262 character used by CU (i.e. the character you use to
2263 issue commands to cu itself instead of sending the command as input
2264 to the connected device) is a '~'. You will need this for use in
2265 only two different ways during normal operations. First is to exit
2266 the program by sending a '~.' which is called a 'escape-disconnect'
2267 and allows you to close-out from 'cu'. The
2268 second use will be outlined later.
2271 All of the Altus Metrum devices share the concept of a two level
2272 command set in their firmware.
2273 The first layer has several single letter commands. Once
2274 you are using 'cu' (or 'cutecom') sending (typing) a '?'
2275 returns a full list of these
2276 commands. The second level are configuration sub-commands accessed
2277 using the 'c' command, for
2278 instance typing 'c?' will give you this second level of commands
2279 (all of which require the
2280 letter 'c' to access). Please note that most configuration options
2281 are stored only in Flash memory; TeleDongle doesn't provide any storage
2282 for these options and so they'll all be lost when you unplug it.
2285 Try setting these configuration ('c' or second level menu) values. A good
2286 place to start is by setting your call sign. By default, the boards
2287 use 'N0CALL' which is cute, but not exactly legal!
2288 Spend a few minutes getting comfortable with the units, their
2289 firmware, and 'cu' (or possibly 'cutecom').
2290 For instance, try to send
2291 (type) a 'c r 2' and verify the channel change by sending a 'c s'.
2292 Verify you can connect and disconnect from the units while in your
2293 terminal program by sending the escape-disconnect mentioned above.
2296 Note that the 'reboot' command, which is very useful on the altimeters,
2297 will likely just cause problems with the dongle. The *correct* way
2298 to reset the dongle is just to unplug and re-plug it.
2301 A fun thing to do at the launch site and something you can do while
2302 learning how to use these units is to play with the RF-link access
2303 between an altimeter and the TeleDongle. Be aware that you *must* create
2304 some physical separation between the devices, otherwise the link will
2305 not function due to signal overload in the receivers in each device.
2308 Now might be a good time to take a break and read the rest of this
2309 manual, particularly about the two "modes" that the altimeters
2310 can be placed in. TeleMetrum uses the position of the device when booting
2311 up will determine whether the unit is in "pad" or "idle" mode. TeleMini
2312 enters "idle" mode when it receives a command packet within the first 5 seconds
2313 of being powered up, otherwise it enters "pad" mode.
2316 You can access an altimeter in idle mode from the TeleDongle's USB
2317 connection using the RF link
2318 by issuing a 'p' command to the TeleDongle. Practice connecting and
2319 disconnecting ('~~' while using 'cu') from the altimeter. If
2320 you cannot escape out of the "p" command, (by using a '~~' when in
2321 CU) then it is likely that your kernel has issues. Try a newer version.
2324 Using this RF link allows you to configure the altimeter, test
2325 fire e-matches and igniters from the flight line, check pyro-match
2326 continuity and so forth. You can leave the unit turned on while it
2327 is in 'idle mode' and then place the
2328 rocket vertically on the launch pad, walk away and then issue a
2329 reboot command. The altimeter will reboot and start sending data
2330 having changed to the "pad" mode. If the TeleDongle is not receiving
2331 this data, you can disconnect 'cu' from the TeleDongle using the
2332 procedures mentioned above and THEN connect to the TeleDongle from
2333 inside 'ao-view'. If this doesn't work, disconnect from the
2334 TeleDongle, unplug it, and try again after plugging it back in.
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!
2377 xmlns:xi="http://www.w3.org/2001/XInclude">
2378 <title>Release Notes</title>
2379 <xi:include href="release-notes-1.0.xsl" xpointer="xpointer(/article/*)"/>
2380 <xi:include href="release-notes-0.9.2.xsl" xpointer="xpointer(/article/*)"/>
2381 <xi:include href="release-notes-0.9.xsl" xpointer="xpointer(/article/*)"/>
2382 <xi:include href="release-notes-0.8.xsl" xpointer="xpointer(/article/*)"/>
2383 <xi:include href="release-notes-0.7.1.xsl" xpointer="xpointer(/article/*)"/>
2387 <!-- LocalWords: Altusmetrum
projects / fw / altos / blob