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>24 August 2011</date>
42 Updated for software version 1.0. Note that 1.0 represents a
43 telemetry format change, meaning both ends of a link
44 (TeleMetrum/TeleMini and TeleDongle) must be updated or
45 communications will fail.
49 <revnumber>0.9</revnumber>
50 <date>18 January 2011</date>
52 Updated for software version 0.9. Note that 0.9 represents a
53 telemetry format change, meaning both ends of a link (TeleMetrum and
54 TeleDongle) must be updated or communications will fail.
58 <revnumber>0.8</revnumber>
59 <date>24 November 2010</date>
60 <revremark>Updated for software version 0.8 </revremark>
66 Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing "The
67 Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter
68 Kit" which formed the basis of the original Getting Started chapter
69 in this book. Bob was one of our first customers for a production
70 TeleMetrum, and his continued enthusiasm and contributions
71 are immensely gratifying and highly appreciated!
74 And thanks to Anthony (AJ) Towns for major contributions including
75 the AltosUI graphing and site map code and associated documentation.
76 Free software means that our customers and friends can become our
77 collaborators, and we certainly appreciate this level of
81 Have fun using these products, and we hope to meet all of you
82 out on the rocket flight line somewhere.
85 NAR #87103, TRA #12201
88 NAR #88757, TRA #12200
93 <title>Introduction and Overview</title>
95 Welcome to the Altus Metrum community! Our circuits and software reflect
96 our passion for both hobby rocketry and Free Software. We hope their
97 capabilities and performance will delight you in every way, but by
98 releasing all of our hardware and software designs under open licenses,
99 we also hope to empower you to take as active a role in our collective
103 The first device created for our community was TeleMetrum, a dual
104 deploy altimeter with fully integrated GPS and radio telemetry
105 as standard features, and a "companion interface" that will
106 support optional capabilities in the future.
109 The newest device is TeleMini, a dual deploy altimeter with
110 radio telemetry and radio direction finding. This device is only
111 13mm by 38mm (½ inch by 1½ inches) and can fit easily in an 18mm
115 Complementing TeleMetrum and TeleMini is TeleDongle, a USB to RF
116 interface for communicating with the altimeters. Combined with your
117 choice of antenna and
118 notebook computer, TeleDongle and our associated user interface software
119 form a complete ground station capable of logging and displaying in-flight
120 telemetry, aiding rocket recovery, then processing and archiving flight
121 data for analysis and review.
124 More products will be added to the Altus Metrum family over time, and
125 we currently envision that this will be a single, comprehensive manual
126 for the entire product family.
130 <title>Getting Started</title>
132 The first thing to do after you check the inventory of parts in your
133 "starter kit" is to charge the battery.
136 The TeleMetrum battery can be charged by plugging it into the
137 corresponding socket of the TeleMetrum and then using the USB A to
139 cable to plug the TeleMetrum into your computer's USB socket. The
140 TeleMetrum circuitry will charge the battery whenever it is plugged
141 in, because the TeleMetrum's on-off switch does NOT control the
145 When the GPS chip is initially searching for
146 satellites, TeleMetrum will consume more current than it can pull
147 from the USB port, so the battery must be attached in order to get
148 satellite lock. Once GPS is locked, the current consumption goes back
149 down enough to enable charging while
150 running. So it's a good idea to fully charge the battery as your
151 first item of business so there is no issue getting and maintaining
152 satellite lock. The yellow charge indicator led will go out when the
153 battery is nearly full and the charger goes to trickle charge. It
154 can take several hours to fully recharge a deeply discharged battery.
157 The TeleMini battery can be charged by disconnecting it from the
158 TeleMini board and plugging it into a standalone battery charger
159 board, and connecting that via a USB cable to a laptop or other USB
163 The other active device in the starter kit is the TeleDongle USB to
164 RF interface. If you plug it in to your Mac or Linux computer it should
165 "just work", showing up as a serial port device. Windows systems need
166 driver information that is part of the AltOS download to know that the
167 existing USB modem driver will work. We therefore recommend installing
168 our software before plugging in TeleDongle if you are using a Windows
169 computer. If you are using Linux and are having problems, try moving
170 to a fresher kernel (2.6.33 or newer), as the USB serial driver had
171 ugly bugs in some earlier versions.
174 Next you should obtain and install the AltOS software. These include
175 the AltosUI ground station program, current firmware images for
176 TeleMetrum, TeleMini and TeleDongle, and a number of standalone
177 utilities that are rarely needed. Pre-built binary packages are
178 available for Linux, Microsoft Windows, and recent MacOSX versions.
179 Full source code and build instructions are also available.
180 The latest version may always be downloaded from
181 <ulink url="http://altusmetrum.org/AltOS"/>.
185 <title>Handling Precautions</title>
187 All Altus Metrum products are sophisticated electronic devices.
188 When handled gently and properly installed in an air-frame, they
189 will deliver impressive results. However, like all electronic
190 devices, there are some precautions you must take.
193 The Lithium Polymer rechargeable batteries have an
194 extraordinary power density. This is great because we can fly with
195 much less battery mass than if we used alkaline batteries or previous
196 generation rechargeable batteries... but if they are punctured
197 or their leads are allowed to short, they can and will release their
199 Thus we recommend that you take some care when handling our batteries
200 and consider giving them some extra protection in your air-frame. We
201 often wrap them in suitable scraps of closed-cell packing foam before
202 strapping them down, for example.
205 The barometric sensors used on both TeleMetrum and TeleMini are
206 sensitive to sunlight. In normal TeleMetrum mounting situations, it
207 and all of the other surface mount components
208 are "down" towards whatever the underlying mounting surface is, so
209 this is not normally a problem. Please consider this, though, when
210 designing an installation, for example, in an air-frame with a
211 see-through plastic payload bay. It is particularly important to
212 consider this with TeleMini, both because the baro sensor is on the
213 "top" of the board, and because many model rockets with payload bays
214 use clear plastic for the payload bay! Replacing these with an opaque
215 cardboard tube, painting them, or wrapping them with a layer of masking
216 tape are all reasonable approaches to keep the sensor out of direct
220 The barometric sensor sampling port must be able to "breathe",
221 both by not being covered by foam or tape or other materials that might
222 directly block the hole on the top of the sensor, and also by having a
223 suitable static vent to outside air.
226 As with all other rocketry electronics, Altus Metrum altimeters must
227 be protected from exposure to corrosive motor exhaust and ejection
232 <title>Hardware Overview</title>
234 TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to
235 fit inside coupler for 29mm air-frame tubing, but using it in a tube that
236 small in diameter may require some creativity in mounting and wiring
237 to succeed! The presence of an accelerometer means TeleMetrum should
238 be aligned along the flight axis of the airframe, and by default the 1/4
239 wave UHF wire antenna should be on the nose-cone end of the board. The
240 antenna wire is about 7 inches long, and wiring for a power switch and
241 the e-matches for apogee and main ejection charges depart from the
242 fin can end of the board, meaning an ideal "simple" avionics
243 bay for TeleMetrum should have at least 10 inches of interior length.
246 TeleMini is a 0.5 inch by 1.5 inch circuit board. It was designed to
247 fit inside an 18mm air-frame tube, but using it in a tube that
248 small in diameter may require some creativity in mounting and wiring
249 to succeed! Since there is no accelerometer, TeleMini can be mounted
250 in any convenient orientation. The default 1/4
251 wave UHF wire antenna attached to the center of one end of
252 the board is about 7 inches long, and wiring for a power switch and
253 the e-matches for apogee and main ejection charges depart from the
254 other end of the board, meaning an ideal "simple" avionics
255 bay for TeleMini should have at least 9 inches of interior length.
258 A typical TeleMetrum or TeleMini installation involves attaching
259 only a suitable Lithium Polymer battery, a single pole switch for
260 power on/off, and two pairs of wires connecting e-matches for the
261 apogee and main ejection charges.
264 By default, we use the unregulated output of the Li-Po battery directly
265 to fire ejection charges. This works marvelously with standard
266 low-current e-matches like the J-Tek from MJG Technologies, and with
267 Quest Q2G2 igniters. However, if you want or need to use a separate
268 pyro battery, check out the "External Pyro Battery" section in this
269 manual for instructions on how to wire that up. The altimeters are
270 designed to work with an external pyro battery of no more than 15 volts.
273 Ejection charges are wired directly to the screw terminal block
274 at the aft end of the altimeter. You'll need a very small straight
275 blade screwdriver for these screws, such as you might find in a
276 jeweler's screwdriver set.
279 TeleMetrum also uses the screw terminal block for the power
280 switch leads. On TeleMini, the power switch leads are soldered
281 directly to the board and can be connected directly to a switch.
284 For most air-frames, the integrated antennas are more than
285 adequate. However, if you are installing in a carbon-fiber or
286 metal electronics bay which is opaque to RF signals, you may need to
287 use off-board external antennas instead. In this case, you can
288 order an altimeter with an SMA connector for the UHF antenna
289 connection, and, on TeleMetrum, you can unplug the integrated GPS
290 antenna and select an appropriate off-board GPS antenna with
291 cable terminating in a U.FL connector.
295 <title>System Operation</title>
297 <title>Firmware Modes </title>
299 The AltOS firmware build for the altimeters has two
300 fundamental modes, "idle" and "flight". Which of these modes
301 the firmware operates in is determined at start up time. For
302 TeleMetrum, the mode is controlled by the orientation of the
303 rocket (well, actually the board, of course...) at the time
304 power is switched on. If the rocket is "nose up", then
305 TeleMetrum assumes it's on a rail or rod being prepared for
306 launch, so the firmware chooses flight mode. However, if the
307 rocket is more or less horizontal, the firmware instead enters
308 idle mode. Since TeleMini doesn't have an accelerometer we can
309 use to determine orientation, "idle" mode is selected when the
310 board receives a command packet within the first five seconds
311 of operation; if no packet is received, the board enters
315 At power on, you will hear three beeps or see three flashes
316 ("S" in Morse code for start up) and then a pause while
317 the altimeter completes initialization and self test, and decides
318 which mode to enter next.
321 In flight or "pad" mode, the altimeter engages the flight
322 state machine, goes into transmit-only mode on the RF link
323 sending telemetry, and waits for launch to be detected.
324 Flight mode is indicated by an "di-dah-dah-dit" ("P" for pad)
325 on the beeper or lights, followed by beeps or flashes
326 indicating the state of the pyrotechnic igniter continuity.
327 One beep/flash indicates apogee continuity, two beeps/flashes
328 indicate main continuity, three beeps/flashes indicate both
329 apogee and main continuity, and one longer "brap" sound or
330 rapidly alternating lights indicates no continuity. For a
331 dual deploy flight, make sure you're getting three beeps or
332 flashes before launching! For apogee-only or motor eject
333 flights, do what makes sense.
336 If idle mode is entered, you will hear an audible "di-dit" or see
337 two short flashes ("I" for idle), and the flight state machine is
338 disengaged, thus no ejection charges will fire. The altimeters also
339 listen on the RF link when in idle mode for requests sent via
340 TeleDongle. Commands can be issued to a TeleMetrum in idle mode
342 USB or the RF link equivalently. TeleMini only has the RF link.
343 Idle mode is useful for configuring the altimeter, for extracting data
344 from the on-board storage chip after flight, and for ground testing
348 One "neat trick" of particular value when TeleMetrum is used with
349 very large air-frames, is that you can power the board up while the
350 rocket is horizontal, such that it comes up in idle mode. Then you can
351 raise the air-frame to launch position, and issue a 'reset' command
352 via TeleDongle over the RF link to cause the altimeter to reboot and
353 come up in flight mode. This is much safer than standing on the top
354 step of a rickety step-ladder or hanging off the side of a launch
355 tower with a screw-driver trying to turn on your avionics before
362 TeleMetrum includes a complete GPS receiver. A complete explanation
363 of how GPS works is beyond the scope of this manual, but the bottom
364 line is that the TeleMetrum GPS receiver needs to lock onto at least
365 four satellites to obtain a solid 3 dimensional position fix and know
369 TeleMetrum provides backup power to the GPS chip any time a
370 battery is connected. This allows the receiver to "warm start" on
371 the launch rail much faster than if every power-on were a GPS
372 "cold start". In typical operations, powering up TeleMetrum
373 on the flight line in idle mode while performing final air-frame
374 preparation will be sufficient to allow the GPS receiver to cold
375 start and acquire lock. Then the board can be powered down during
376 RSO review and installation on a launch rod or rail. When the board
377 is turned back on, the GPS system should lock very quickly, typically
378 long before igniter installation and return to the flight line are
383 <title>Controlling An Altimeter Over The Radio Link</title>
385 One of the unique features of the Altus Metrum system is
386 the ability to create a two way command link between TeleDongle
387 and an altimeter using the digital radio transceivers built into
388 each device. This allows you to interact with the altimeter from
389 afar, as if it were directly connected to the computer.
392 Any operation which can be performed with TeleMetrum can
393 either be done with TeleMetrum directly connected to the
394 computer via the USB cable, or through the radio
395 link. TeleMini doesn't provide a USB connector and so it is
396 always controlled through the radio link. Select the
397 appropriate TeleDongle device when the list of devices is
398 presented and AltosUI will interact with an altimter over the
402 One oddity in the current interface is how AltosUI selects the
403 frequency for packet mode communications. Instead of providing
404 an interface to specifically configure the frequency, it uses
405 whatever frequency was most recently selected for the target
406 TeleDongle device in Monitor Flight mode. If you haven't ever
407 used that mode with the TeleDongle in question, select the
408 Monitor Flight button from the top level UI, pick the
409 appropriate TeleDongle device. Once the flight monitoring
410 window is open, select the desired frequency and then close it
411 down again. All Packet Command Mode operations will now use
417 Save Flight Data—Recover flight data from the rocket without
423 Configure altimeter apogee delays or main deploy heights
424 to respond to changing launch conditions. You can also
425 'reboot' the altimeter. Use this to remotely enable the
426 flight computer by turning TeleMetrum on in "idle" mode,
427 then once the air-frame is oriented for launch, you can
428 reboot the altimeter and have it restart in pad mode
429 without having to climb the scary ladder.
434 Fire Igniters—Test your deployment charges without snaking
435 wires out through holes in the air-frame. Simply assembly the
436 rocket as if for flight with the apogee and main charges
437 loaded, then remotely command the altimeter to fire the
443 Packet command mode uses the same RF frequencies as telemetry
444 mode. Configure the desired TeleDongle frequency using the
445 flight monitor window frequency selector and then close that
446 window before performing the desired operation.
449 TeleMetrum only enables packet command mode in 'idle' mode, so
450 make sure you have TeleMetrum lying horizontally when you turn
451 it on. Otherwise, TeleMetrum will start in 'pad' mode ready for
452 flight and will not be listening for command packets from TeleDongle.
455 TeleMini listens for a command packet for five seconds after
456 first being turned on, if it doesn't hear anything, it enters
457 'pad' mode, ready for flight and will no longer listen for
458 command packets. The easiest way to connect to TeleMini is to
459 initiate the command and select the TeleDongle device. At this
460 point, the TeleDongle will be attempting to communicate with
461 the TeleMini. Now turn TeleMini on, and it should immediately
462 start communicating with the TeleDongle and the desired
463 operation can be performed.
466 When packet command mode is enabled, you can monitor the link
467 by watching the lights on the
468 devices. The red LED will flash each time they
469 transmit a packet while the green LED will light up
470 on TeleDongle while it is waiting to receive a packet from
475 <title>Ground Testing </title>
477 An important aspect of preparing a rocket using electronic deployment
478 for flight is ground testing the recovery system. Thanks
479 to the bi-directional RF link central to the Altus Metrum system,
480 this can be accomplished in a TeleMetrum or TeleMini equipped rocket
481 with less work than you may be accustomed to with other systems. It
485 Just prep the rocket for flight, then power up the altimeter
486 in "idle" mode (placing air-frame horizontal for TeleMetrum or
487 selected the Configure Altimeter tab for TeleMini). This will cause
488 the firmware to go into "idle" mode, in which the normal flight
489 state machine is disabled and charges will not fire without
490 manual command. You can now command the altimeter to fire the apogee
491 or main charges from a safe distance using your computer and
492 TeleDongle and the Fire Igniter tab to complete ejection testing.
496 <title>Radio Link </title>
498 The chip our boards are based on incorporates an RF transceiver, but
499 it's not a full duplex system... each end can only be transmitting or
500 receiving at any given moment. So we had to decide how to manage the
504 By design, the altimeter firmware listens for an RF connection when
505 it's in "idle mode", which
506 allows us to use the RF link to configure the rocket, do things like
507 ejection tests, and extract data after a flight without having to
508 crack open the air-frame. However, when the board is in "flight
509 mode", the altimeter only
510 transmits and doesn't listen at all. That's because we want to put
511 ultimate priority on event detection and getting telemetry out of
512 the rocket and out over
513 the RF link in case the rocket crashes and we aren't able to extract
517 We don't use a 'normal packet radio' mode like APRS because they're
518 just too inefficient. The GFSK modulation we use is FSK with the
519 base-band pulses passed through a
520 Gaussian filter before they go into the modulator to limit the
521 transmitted bandwidth. When combined with the hardware forward error
522 correction support in the cc1111 chip, this allows us to have a very
523 robust 38.4 kilobit data link with only 10 milliwatts of transmit
524 power, a whip antenna in the rocket, and a hand-held Yagi on the
525 ground. We've had flights to above 21k feet AGL with great reception,
526 and calculations suggest we should be good to well over 40k feet AGL
527 with a 5-element yagi on the ground. We hope to fly boards to higher
528 altitudes over time, and would of course appreciate customer feedback
529 on performance in higher altitude flights!
533 <title>Configurable Parameters</title>
535 Configuring an Altus Metrum altimeter for flight is very
536 simple. Even on our baro-only TeleMini board, the use of a Kalman
537 filter means there is no need to set a "mach delay". The few
538 configurable parameters can all be set using AltosUI over USB or
539 or RF link via TeleDongle.
542 <title>Radio Frequencies</title>
544 The Altus Metrum boards support frequencies in the 70cm
545 band. By default, the configuration interface provides a
546 list of 10 common frequencies in 100kHz channels starting at
547 434.550MHz. However, the firmware supports use of
548 any 50kHz multiple within the 70cm band. At any given
549 launch, we highly recommend coordinating who will use each
550 frequency and when to avoid interference. And of course, both
551 altimeter and TeleDongle must be configured to the same
552 frequency to successfully communicate with each other.
555 To set the radio frequency, use the 'c R' command to specify the
556 radio transceiver configuration parameter. This parameter is computed
557 using the desired frequency, 'F', the radio calibration parameter, 'C' (showed by the 'c s' command) and
558 the standard calibration reference frequency, 'S', (normally 434.550MHz):
562 Round the result to the nearest integer value.
563 As with all 'c' sub-commands, follow this with a 'c w' to write the
564 change to the parameter block in the on-board flash on
565 your altimeter board if you want the change to stay in place across reboots.
569 <title>Apogee Delay</title>
571 Apogee delay is the number of seconds after the altimeter detects flight
572 apogee that the drogue charge should be fired. In most cases, this
573 should be left at the default of 0. However, if you are flying
574 redundant electronics such as for an L3 certification, you may wish
575 to set one of your altimeters to a positive delay so that both
576 primary and backup pyrotechnic charges do not fire simultaneously.
579 To set the apogee delay, use the 'c d' command.
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 Please note that the Altus Metrum apogee detection algorithm
585 fires exactly at apogee. If you are also flying an
586 altimeter like the PerfectFlite MAWD, which only supports
587 selecting 0 or 1 seconds of apogee delay, you may wish to
588 set the MAWD to 0 seconds delay and set the TeleMetrum to
589 fire your backup 2 or 3 seconds later to avoid any chance of
590 both charges firing simultaneously. We've flown several
591 air-frames this way quite happily, including Keith's
596 <title>Main Deployment Altitude</title>
598 By default, the altimeter will fire the main deployment charge at an
599 elevation of 250 meters (about 820 feet) above ground. We think this
600 is a good elevation for most air-frames, but feel free to change this
601 to suit. In particular, if you are flying two altimeters, you may
603 deployment elevation for the backup altimeter to be something lower
604 than the primary so that both pyrotechnic charges don't fire
608 To set the main deployment altitude, use the 'c m' command.
609 As with all 'c' sub-commands, follow this with a 'c w' to write the
610 change to the parameter block in the on-board DataFlash chip.
615 <title>Calibration</title>
617 There are only two calibrations required for a TeleMetrum board, and
618 only one for TeleDongle and TeleMini.
621 <title>Radio Frequency</title>
623 The radio frequency is synthesized from a clock based on the 48 MHz
624 crystal on the board. The actual frequency of this oscillator must be
625 measured to generate a calibration constant. While our GFSK modulation
626 bandwidth is wide enough to allow boards to communicate even when
627 their oscillators are not on exactly the same frequency, performance
628 is best when they are closely matched.
629 Radio frequency calibration requires a calibrated frequency counter.
630 Fortunately, once set, the variation in frequency due to aging and
631 temperature changes is small enough that re-calibration by customers
632 should generally not be required.
635 To calibrate the radio frequency, connect the UHF antenna port to a
636 frequency counter, set the board to 434.550MHz, and use the 'C'
637 command to generate a CW carrier. Wait for the transmitter temperature
638 to stabilize and the frequency to settle down.
639 Then, divide 434.550 MHz by the
640 measured frequency and multiply by the current radio cal value show
641 in the 'c s' command. For an unprogrammed board, the default value
642 is 1186611. Take the resulting integer and program it using the 'c f'
643 command. Testing with the 'C' command again should show a carrier
644 within a few tens of Hertz of the intended frequency.
645 As with all 'c' sub-commands, follow this with a 'c w' to write the
646 change to the parameter block in the on-board DataFlash chip.
649 when the radio calibration value is changed, the radio
650 frequency value is reset to the same value, so you'll need
651 to recompute and reset the radio frequency value using the
652 new radio calibration value.
656 <title>TeleMetrum Accelerometer</title>
658 The TeleMetrum accelerometer we use has its own 5 volt power supply and
659 the output must be passed through a resistive voltage divider to match
660 the input of our 3.3 volt ADC. This means that unlike the barometric
661 sensor, the output of the acceleration sensor is not ratio-metric to
662 the ADC converter, and calibration is required. We also support the
663 use of any of several accelerometers from a Freescale family that
664 includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity,
665 a simple 2-point calibration yields acceptable results capturing both
666 the different sensitivities and ranges of the different accelerometer
667 parts and any variation in power supply voltages or resistor values
668 in the divider network.
671 To calibrate the acceleration sensor, use the 'c a 0' command. You
672 will be prompted to orient the board vertically with the UHF antenna
673 up and press a key, then to orient the board vertically with the
674 UHF antenna down and press a key.
675 As with all 'c' sub-commands, follow this with a 'c w' to write the
676 change to the parameter block in the on-board DataFlash chip.
679 The +1g and -1g calibration points are included in each telemetry
680 frame and are part of the header extracted by ao-dumplog after flight.
681 Note that we always store and return raw ADC samples for each
682 sensor... nothing is permanently "lost" or "damaged" if the
686 In the unlikely event an accel cal that goes badly, it is possible
687 that TeleMetrum may always come up in 'pad mode' and as such not be
688 listening to either the USB or radio interfaces. If that happens,
689 there is a special hook in the firmware to force the board back
690 in to 'idle mode' so you can re-do the cal. To use this hook, you
691 just need to ground the SPI clock pin at power-on. This pin is
692 available as pin 2 on the 8-pin companion connector, and pin 1 is
693 ground. So either carefully install a fine-gauge wire jumper
694 between the two pins closest to the index hole end of the 8-pin
695 connector, or plug in the programming cable to the 8-pin connector
696 and use a small screwdriver or similar to short the two pins closest
697 to the index post on the 4-pin end of the programming cable, and
698 power up the board. It should come up in 'idle mode' (two beeps).
703 <title>Updating Device Firmware</title>
705 The big conceptual thing to realize is that you have to use a
706 TeleDongle as a programmer to update a TeleMetrum or TeleMini,
707 and a TeleMetrum or other TeleDongle to program the TeleDongle
708 Due to limited memory resources in the cc1111, we don't support
709 programming directly over USB.
712 You may wish to begin by ensuring you have current firmware images.
713 These are distributed as part of the AltOS software bundle that
714 also includes the AltosUI ground station program. Newer ground
715 station versions typically work fine with older firmware versions,
716 so you don't need to update your devices just to try out new
717 software features. You can always download the most recent
718 version from <ulink url="http://www.altusmetrum.org/AltOS/"/>.
721 We recommend updating the altimeter first, before updating TeleDongle.
724 <title>Updating TeleMetrum Firmware</title>
725 <orderedlist inheritnum='inherit' numeration='arabic'>
727 Find the 'programming cable' that you got as part of the starter
728 kit, that has a red 8-pin MicroMaTch connector on one end and a
729 red 4-pin MicroMaTch connector on the other end.
732 Take the 2 screws out of the TeleDongle case to get access
733 to the circuit board.
736 Plug the 8-pin end of the programming cable to the
737 matching connector on the TeleDongle, and the 4-pin end to the
738 matching connector on the TeleMetrum.
739 Note that each MicroMaTch connector has an alignment pin that
740 goes through a hole in the PC board when you have the cable
744 Attach a battery to the TeleMetrum board.
747 Plug the TeleDongle into your computer's USB port, and power
751 Run AltosUI, and select 'Flash Image' from the File menu.
754 Pick the TeleDongle device from the list, identifying it as the
758 Select the image you want put on the TeleMetrum, which should have a
759 name in the form telemetrum-v1.1-1.0.0.ihx. It should be visible
760 in the default directory, if not you may have to poke around
761 your system to find it.
764 Make sure the configuration parameters are reasonable
765 looking. If the serial number and/or RF configuration
766 values aren't right, you'll need to change them.
769 Hit the 'OK' button and the software should proceed to flash
770 the TeleMetrum with new firmware, showing a progress bar.
773 Confirm that the TeleMetrum board seems to have updated OK, which you
774 can do by plugging in to it over USB and using a terminal program
775 to connect to the board and issue the 'v' command to check
779 If something goes wrong, give it another try.
784 <title>Updating TeleMini Firmware</title>
785 <orderedlist inheritnum='inherit' numeration='arabic'>
787 You'll need a special 'programming cable' to reprogram the
788 TeleMini. It's available on the Altus Metrum web store, or
789 you can make your own using an 8-pin MicroMaTch connector on
790 one end and a set of four pins on the other.
793 Take the 2 screws out of the TeleDongle case to get access
794 to the circuit board.
797 Plug the 8-pin end of the programming cable to the matching
798 connector on the TeleDongle, and the 4-pins into the holes
799 in the TeleMini circuit board. Note that the MicroMaTch
800 connector has an alignment pin that goes through a hole in
801 the PC board when you have the cable oriented correctly, and
802 that pin 1 on the TeleMini board is marked with a square pad
803 while the other pins have round pads.
806 Attach a battery to the TeleMini board.
809 Plug the TeleDongle into your computer's USB port, and power
813 Run AltosUI, and select 'Flash Image' from the File menu.
816 Pick the TeleDongle device from the list, identifying it as the
820 Select the image you want put on the TeleMini, which should have a
821 name in the form telemini-v1.0-1.0.0.ihx. It should be visible
822 in the default directory, if not you may have to poke around
823 your system to find it.
826 Make sure the configuration parameters are reasonable
827 looking. If the serial number and/or RF configuration
828 values aren't right, you'll need to change them.
831 Hit the 'OK' button and the software should proceed to flash
832 the TeleMini with new firmware, showing a progress bar.
835 Confirm that the TeleMini board seems to have updated OK, which you
836 can do by configuring it over the RF link through the TeleDongle, or
837 letting it come up in "flight" mode and listening for telemetry.
840 If something goes wrong, give it another try.
845 <title>Updating TeleDongle Firmware</title>
847 Updating TeleDongle's firmware is just like updating TeleMetrum or TeleMini
848 firmware, but you use either a TeleMetrum or another TeleDongle as the programmer.
850 <orderedlist inheritnum='inherit' numeration='arabic'>
852 Find the 'programming cable' that you got as part of the starter
853 kit, that has a red 8-pin MicroMaTch connector on one end and a
854 red 4-pin MicroMaTch connector on the other end.
857 Find the USB cable that you got as part of the starter kit, and
858 plug the "mini" end in to the mating connector on TeleMetrum or TeleDongle.
861 Take the 2 screws out of the TeleDongle case to get access
862 to the circuit board.
865 Plug the 8-pin end of the programming cable to the
866 matching connector on the programmer, and the 4-pin end to the
867 matching connector on the TeleDongle.
868 Note that each MicroMaTch connector has an alignment pin that
869 goes through a hole in the PC board when you have the cable
873 Attach a battery to the TeleMetrum board if you're using one.
876 Plug both the programmer and the TeleDongle into your computer's USB
877 ports, and power up the programmer.
880 Run AltosUI, and select 'Flash Image' from the File menu.
883 Pick the programmer device from the list, identifying it as the
887 Select the image you want put on the TeleDongle, which should have a
888 name in the form teledongle-v0.2-1.0.0.ihx. It should be visible
889 in the default directory, if not you may have to poke around
890 your system to find it.
893 Make sure the configuration parameters are reasonable
894 looking. If the serial number and/or RF configuration
895 values aren't right, you'll need to change them. The TeleDongle
896 serial number is on the "bottom" of the circuit board, and can
897 usually be read through the translucent blue plastic case without
898 needing to remove the board from the case.
901 Hit the 'OK' button and the software should proceed to flash
902 the TeleDongle with new firmware, showing a progress bar.
905 Confirm that the TeleDongle board seems to have updated OK, which you
906 can do by plugging in to it over USB and using a terminal program
907 to connect to the board and issue the 'v' command to check
908 the version, etc. Once you're happy, remove the programming cable
909 and put the cover back on the TeleDongle.
912 If something goes wrong, give it another try.
916 Be careful removing the programming cable from the locking 8-pin
917 connector on TeleMetrum. You'll need a fingernail or perhaps a thin
918 screwdriver or knife blade to gently pry the locking ears out
919 slightly to extract the connector. We used a locking connector on
920 TeleMetrum to help ensure that the cabling to companion boards
921 used in a rocket don't ever come loose accidentally in flight.
929 <title>AltosUI</title>
931 The AltosUI program provides a graphical user interface for
932 interacting with the Altus Metrum product family, including
933 TeleMetrum, TeleMini and TeleDongle. AltosUI can monitor telemetry data,
934 configure TeleMetrum, TeleMini and TeleDongle devices and many other
935 tasks. The primary interface window provides a selection of
936 buttons, one for each major activity in the system. This manual
937 is split into chapters, each of which documents one of the tasks
938 provided from the top-level toolbar.
941 <title>Monitor Flight</title>
942 <subtitle>Receive, Record and Display Telemetry Data</subtitle>
944 Selecting this item brings up a dialog box listing all of the
945 connected TeleDongle devices. When you choose one of these,
946 AltosUI will create a window to display telemetry data as
947 received by the selected TeleDongle device.
950 All telemetry data received are automatically recorded in
951 suitable log files. The name of the files includes the current
952 date and rocket serial and flight numbers.
955 The radio frequency being monitored by the TeleDongle device is
956 displayed at the top of the window. You can configure the
957 frequency by clicking on the frequency box and selecting the desired
958 frequency. AltosUI remembers the last frequency selected for each
959 TeleDongle and selects that automatically the next time you use
963 Below the TeleDongle frequency selector, the window contains a few
964 significant pieces of information about the altimeter providing
965 the telemetry data stream:
969 <para>The configured call-sign</para>
972 <para>The device serial number</para>
975 <para>The flight number. Each altimeter remembers how many
981 The rocket flight state. Each flight passes through several
982 states including Pad, Boost, Fast, Coast, Drogue, Main and
988 The Received Signal Strength Indicator value. This lets
989 you know how strong a signal TeleDongle is receiving. The
990 radio inside TeleDongle operates down to about -99dBm;
991 weaker signals may not be receivable. The packet link uses
992 error correction and detection techniques which prevent
993 incorrect data from being reported.
998 Finally, the largest portion of the window contains a set of
999 tabs, each of which contain some information about the rocket.
1000 They're arranged in 'flight order' so that as the flight
1001 progresses, the selected tab automatically switches to display
1002 data relevant to the current state of the flight. You can select
1003 other tabs at any time. The final 'table' tab contains all of
1004 the telemetry data in one place.
1007 <title>Launch Pad</title>
1009 The 'Launch Pad' tab shows information used to decide when the
1010 rocket is ready for flight. The first elements include red/green
1011 indicators, if any of these is red, you'll want to evaluate
1012 whether the rocket is ready to launch:
1016 Battery Voltage. This indicates whether the Li-Po battery
1017 powering the TeleMetrum has sufficient charge to last for
1018 the duration of the flight. A value of more than
1019 3.7V is required for a 'GO' status.
1024 Apogee Igniter Voltage. This indicates whether the apogee
1025 igniter has continuity. If the igniter has a low
1026 resistance, then the voltage measured here will be close
1027 to the Li-Po battery voltage. A value greater than 3.2V is
1028 required for a 'GO' status.
1033 Main Igniter Voltage. This indicates whether the main
1034 igniter has continuity. If the igniter has a low
1035 resistance, then the voltage measured here will be close
1036 to the Li-Po battery voltage. A value greater than 3.2V is
1037 required for a 'GO' status.
1042 On-board Data Logging. This indicates whether there is
1043 space remaining on-board to store flight data for the
1044 upcoming flight. If you've downloaded data, but failed
1045 to erase flights, there may not be any space
1046 left. TeleMetrum can store multiple flights, depending
1047 on the configured maximum flight log size. TeleMini
1048 stores only a single flight, so it will need to be
1049 downloaded and erased after each flight to capture
1050 data. This only affects on-board flight logging; the
1051 altimeter will still transmit telemetry and fire
1052 ejection charges at the proper times.
1057 GPS Locked. For a TeleMetrum device, this indicates whether the GPS receiver is
1058 currently able to compute position information. GPS requires
1059 at least 4 satellites to compute an accurate position.
1064 GPS Ready. For a TeleMetrum device, this indicates whether GPS has reported at least
1065 10 consecutive positions without losing lock. This ensures
1066 that the GPS receiver has reliable reception from the
1072 The Launchpad tab also shows the computed launch pad position
1073 and altitude, averaging many reported positions to improve the
1074 accuracy of the fix.
1079 <title>Ascent</title>
1081 This tab is shown during Boost, Fast and Coast
1082 phases. The information displayed here helps monitor the
1083 rocket as it heads towards apogee.
1086 The height, speed and acceleration are shown along with the
1087 maximum values for each of them. This allows you to quickly
1088 answer the most commonly asked questions you'll hear during
1092 The current latitude and longitude reported by the TeleMetrum GPS are
1093 also shown. Note that under high acceleration, these values
1094 may not get updated as the GPS receiver loses position
1095 fix. Once the rocket starts coasting, the receiver should
1096 start reporting position again.
1099 Finally, the current igniter voltages are reported as in the
1100 Launch Pad tab. This can help diagnose deployment failures
1101 caused by wiring which comes loose under high acceleration.
1105 <title>Descent</title>
1107 Once the rocket has reached apogee and (we hope) activated the
1108 apogee charge, attention switches to tracking the rocket on
1109 the way back to the ground, and for dual-deploy flights,
1110 waiting for the main charge to fire.
1113 To monitor whether the apogee charge operated correctly, the
1114 current descent rate is reported along with the current
1115 height. Good descent rates generally range from 15-30m/s.
1118 For TeleMetrum altimeters, you can locate the rocket in the sky
1119 using the elevation and
1120 bearing information to figure out where to look. Elevation is
1121 in degrees above the horizon. Bearing is reported in degrees
1122 relative to true north. Range can help figure out how big the
1123 rocket will appear. Note that all of these values are relative
1124 to the pad location. If the elevation is near 90°, the rocket
1125 is over the pad, not over you.
1128 Finally, the igniter voltages are reported in this tab as
1129 well, both to monitor the main charge as well as to see what
1130 the status of the apogee charge is.
1134 <title>Landed</title>
1136 Once the rocket is on the ground, attention switches to
1137 recovery. While the radio signal is generally lost once the
1138 rocket is on the ground, the last reported GPS position is
1139 generally within a short distance of the actual landing location.
1142 The last reported GPS position is reported both by
1143 latitude and longitude as well as a bearing and distance from
1144 the launch pad. The distance should give you a good idea of
1145 whether you'll want to walk or hitch a ride. Take the reported
1146 latitude and longitude and enter them into your hand-held GPS
1147 unit and have that compute a track to the landing location.
1150 Both TeleMini and TeleMetrum will continue to transmit RDF
1151 tones after landing, allowing you to locate the rocket by
1152 following the radio signal. You may need to get away from
1153 the clutter of the flight line, or even get up on a hill (or
1154 your neighbor's RV) to receive the RDF signal.
1157 The maximum height, speed and acceleration reported
1158 during the flight are displayed for your admiring observers.
1161 To get more detailed information about the flight, you can
1162 click on the 'Graph Flight' button which will bring up a
1163 graph window for the current flight.
1167 <title>Site Map</title>
1169 When the TeleMetrum gets a GPS fix, the Site Map tab will map
1170 the rocket's position to make it easier for you to locate the
1171 rocket, both while it is in the air, and when it has landed. The
1172 rocket's state is indicated by color: white for pad, red for
1173 boost, pink for fast, yellow for coast, light blue for drogue,
1174 dark blue for main, and black for landed.
1177 The map's scale is approximately 3m (10ft) per pixel. The map
1178 can be dragged using the left mouse button. The map will attempt
1179 to keep the rocket roughly centered while data is being received.
1182 Images are fetched automatically via the Google Maps Static API,
1183 and are cached for reuse. If map images cannot be downloaded,
1184 the rocket's path will be traced on a dark gray background
1188 You can pre-load images for your favorite launch sites
1189 before you leave home; check out the 'Preload Maps' section below.
1194 <title>Save Flight Data</title>
1196 The altimeter records flight data to its internal flash memory.
1197 The TeleMetrum data is recorded at a much higher rate than the telemetry
1198 system can handle, and is not subject to radio drop-outs. As
1199 such, it provides a more complete and precise record of the
1200 flight. The 'Save Flight Data' button allows you to read the
1201 flash memory and write it to disk. As TeleMini has only a barometer, it
1202 records data at the same rate as the telemetry signal, but there will be
1203 no data lost due to telemetry drop-outs.
1206 Clicking on the 'Save Flight Data' button brings up a list of
1207 connected TeleMetrum and TeleDongle devices. If you select a
1208 TeleMetrum device, the flight data will be downloaded from that
1209 device directly. If you select a TeleDongle device, flight data
1210 will be downloaded from a TeleMetrum or TeleMini device connected via the
1211 packet command link to the specified TeleDongle. See the chapter
1212 on Packet Command Mode for more information about this.
1215 After the device has been selected, a dialog showing the
1216 flight data saved in the device will be shown allowing you to
1217 select which flights to download and which to delete. With
1218 version 0.9 or newer firmware, you must erase flights in order
1219 for the space they consume to be reused by another
1220 flight. This prevents you from accidentally losing flight data
1221 if you neglect to download data before flying again. Note that
1222 if there is no more space available in the device, then no
1223 data will be recorded for a flight.
1226 The file name for each flight log is computed automatically
1227 from the recorded flight date, altimeter serial number and
1228 flight number information.
1232 <title>Replay Flight</title>
1234 Select this button and you are prompted to select a flight
1235 record file, either a .telem file recording telemetry data or a
1236 .eeprom file containing flight data saved from the altimeter
1240 Once a flight record is selected, the flight monitor interface
1241 is displayed and the flight is re-enacted in real time. Check
1242 the Monitor Flight chapter above to learn how this window operates.
1246 <title>Graph Data</title>
1248 Select this button and you are prompted to select a flight
1249 record file, either a .telem file recording telemetry data or a
1250 .eeprom file containing flight data saved from
1254 Once a flight record is selected, a window with two tabs is
1255 opened. The first tab contains a graph with acceleration
1256 (blue), velocity (green) and altitude (red) of the flight are
1257 plotted and displayed, measured in metric units. The
1258 apogee(yellow) and main(magenta) igniter voltages are also
1259 displayed; high voltages indicate continuity, low voltages
1260 indicate open circuits. The second tab contains some basic
1264 The graph can be zoomed into a particular area by clicking and
1265 dragging down and to the right. Once zoomed, the graph can be
1266 reset by clicking and dragging up and to the left. Holding down
1267 control and clicking and dragging allows the graph to be panned.
1268 The right mouse button causes a pop-up menu to be displayed, giving
1269 you the option save or print the plot.
1272 Note that telemetry files will generally produce poor graphs
1273 due to the lower sampling rate and missed telemetry packets.
1274 Use saved flight data for graphing where possible.
1278 <title>Export Data</title>
1280 This tool takes the raw data files and makes them available for
1281 external analysis. When you select this button, you are prompted to select a flight
1282 data file (either .eeprom or .telem will do, remember that
1283 .eeprom files contain higher resolution and more continuous
1284 data). Next, a second dialog appears which is used to select
1285 where to write the resulting file. It has a selector to choose
1286 between CSV and KML file formats.
1289 <title>Comma Separated Value Format</title>
1291 This is a text file containing the data in a form suitable for
1292 import into a spreadsheet or other external data analysis
1293 tool. The first few lines of the file contain the version and
1294 configuration information from the altimeter, then
1295 there is a single header line which labels all of the
1296 fields. All of these lines start with a '#' character which
1297 most tools can be configured to skip over.
1300 The remaining lines of the file contain the data, with each
1301 field separated by a comma and at least one space. All of
1302 the sensor values are converted to standard units, with the
1303 barometric data reported in both pressure, altitude and
1304 height above pad units.
1308 <title>Keyhole Markup Language (for Google Earth)</title>
1310 This is the format used by
1311 Googleearth to provide an overlay within that
1312 application. With this, you can use Googleearth to see the
1313 whole flight path in 3D.
1318 <title>Configure Altimeter</title>
1320 Select this button and then select either a TeleMetrum or
1321 TeleDongle Device from the list provided. Selecting a TeleDongle
1322 device will use Packet Command Mode to configure a remote
1323 altimeter. Learn how to use this in the Packet Command
1327 The first few lines of the dialog provide information about the
1328 connected device, including the product name,
1329 software version and hardware serial number. Below that are the
1330 individual configuration entries.
1333 At the bottom of the dialog, there are four buttons:
1338 Save. This writes any changes to the
1339 configuration parameter block in flash memory. If you don't
1340 press this button, any changes you make will be lost.
1345 Reset. This resets the dialog to the most recently saved values,
1346 erasing any changes you have made.
1351 Reboot. This reboots the device. Use this to
1352 switch from idle to pad mode by rebooting once the rocket is
1353 oriented for flight.
1358 Close. This closes the dialog. Any unsaved changes will be
1364 The rest of the dialog contains the parameters to be configured.
1367 <title>Main Deploy Altitude</title>
1369 This sets the altitude (above the recorded pad altitude) at
1370 which the 'main' igniter will fire. The drop-down menu shows
1371 some common values, but you can edit the text directly and
1372 choose whatever you like. If the apogee charge fires below
1373 this altitude, then the main charge will fire two seconds
1374 after the apogee charge fires.
1378 <title>Apogee Delay</title>
1380 When flying redundant electronics, it's often important to
1381 ensure that multiple apogee charges don't fire at precisely
1382 the same time as that can over pressurize the apogee deployment
1383 bay and cause a structural failure of the air-frame. The Apogee
1384 Delay parameter tells the flight computer to fire the apogee
1385 charge a certain number of seconds after apogee has been
1390 <title>Radio Frequency</title>
1392 This configures which of the configured frequencies to use for both
1393 telemetry and packet command mode. Note that if you set this
1394 value via packet command mode, you will have to reconfigure
1395 the TeleDongle frequency before you will be able to use packet
1400 <title>Radio Calibration</title>
1402 The radios in every Altus Metrum device are calibrated at the
1403 factory to ensure that they transmit and receive on the
1404 specified frequency. You can adjust that
1405 calibration by changing this value. To change the TeleDongle's
1406 calibration, you must reprogram the unit completely.
1410 <title>Callsign</title>
1412 This sets the call sign included in each telemetry packet. Set this
1413 as needed to conform to your local radio regulations.
1417 <title>Maximum Flight Log Size</title>
1419 This sets the space (in kilobytes) allocated for each flight
1420 log. The available space will be divided into chunks of this
1421 size. A smaller value will allow more flights to be stored,
1422 a larger value will record data from longer flights.
1425 During ascent, TeleMetrum records barometer and
1426 accelerometer values 100 times per second, other analog
1427 information (voltages and temperature) 6 times per second
1428 and GPS data once per second. During descent, the non-GPS
1429 data is recorded 1/10th as often. Each barometer +
1430 accelerometer record takes 8 bytes.
1433 The default, 192kB, will store over 200 seconds of data at
1434 the ascent rate, or over 2000 seconds of data at the descent
1435 rate. That's plenty for most flights. This leaves enough
1436 storage for five flights in a 1MB system, or 10 flights in a
1440 The configuration block takes the last available block of
1441 memory, on v1.0 boards that's just 256 bytes. However, the
1442 flash part on the v1.1 boards uses 64kB for each block.
1445 TeleMini has 5kB of on-board storage, which is plenty for a
1446 single flight. Make sure you download and delete the data
1447 before a subsequent flight or it will not log any data.
1451 <title>Ignite Mode</title>
1453 TeleMetrum and TeleMini provide two igniter channels as they
1454 were originally designed as dual-deploy flight
1455 computers. This configuration parameter allows the two
1456 channels to be used in different configurations.
1461 Dual Deploy. This is the usual mode of operation; the
1462 'apogee' channel is fired at apogee and the 'main'
1463 channel at the height above ground specified by the
1464 'Main Deploy Altitude' during descent.
1469 Redundant Apogee. This fires both channels at
1470 apogee, the 'apogee' channel first followed after a two second
1471 delay by the 'main' channel.
1476 Redundant Main. This fires both channels at the
1477 height above ground specified by the Main Deploy
1478 Altitude setting during descent. The 'apogee'
1479 channel is fired first, followed after a two second
1480 delay by the 'main' channel.
1486 <title>Pad Orientation</title>
1488 Because it includes an accelerometer, TeleMetrum is
1489 sensitive to the orientation of the board. By default, it
1490 expects the antenna end to point forward. This parameter
1491 allows that default to be changed, permitting the board to
1492 be mounted with the antenna pointing aft instead.
1497 Antenna Up. In this mode, the antenna end of the
1498 TeleMetrum board must point forward, in line with the
1499 expected flight path.
1504 Antenna Down. In this mode, the antenna end of the
1505 TeleMetrum board must point aft, in line with the
1506 expected flight path.
1513 <title>Configure AltosUI</title>
1515 This button presents a dialog so that you can configure the AltosUI global settings.
1518 <title>Voice Settings</title>
1520 AltosUI provides voice announcements during flight so that you
1521 can keep your eyes on the sky and still get information about
1522 the current flight status. However, sometimes you don't want
1527 <para>Enable—turns all voice announcements on and off</para>
1531 Test Voice—Plays a short message allowing you to verify
1532 that the audio system is working and the volume settings
1539 <title>Log Directory</title>
1541 AltosUI logs all telemetry data and saves all TeleMetrum flash
1542 data to this directory. This directory is also used as the
1543 staring point when selecting data files for display or export.
1546 Click on the directory name to bring up a directory choosing
1547 dialog, select a new directory and click 'Select Directory' to
1548 change where AltosUI reads and writes data files.
1552 <title>Callsign</title>
1554 This value is used in command packet mode and is transmitted
1555 in each packet sent from TeleDongle and received from
1556 TeleMetrum. It is not used in telemetry mode as that transmits
1557 packets only from TeleMetrum to TeleDongle. Configure this
1558 with the AltosUI operators call sign as needed to comply with
1559 your local radio regulations.
1563 <title>Font Size</title>
1565 Selects the set of fonts used in the flight monitor
1566 window. Choose between the small, medium and large sets.
1570 <title>Serial Debug</title>
1572 This causes all communication with a connected device to be
1573 dumped to the console from which AltosUI was started. If
1574 you've started it from an icon or menu entry, the output
1575 will simply be discarded. This mode can be useful to debug
1576 various serial communication issues.
1580 <title>Manage Frequencies</title>
1582 This brings up a dialog where you can configure the set of
1583 frequencies shown in the various frequency menus. You can
1584 add as many as you like, or even reconfigure the default
1585 set. Changing this list does not affect the frequency
1586 settings of any devices, it only changes the set of
1587 frequencies shown in the menus.
1592 <title>Flash Image</title>
1594 This reprograms any Altus Metrum device by using a TeleMetrum
1595 or TeleDongle as a programming dongle. Please read the
1596 directions for flashing devices in the Updating Device
1597 Firmware section above
1600 Once you have the programmer and target devices connected,
1601 push the 'Flash Image' button. That will present a dialog box
1602 listing all of the connected devices. Carefully select the
1603 programmer device, not the device to be programmed.
1606 Next, select the image to flash to the device. These are named
1607 with the product name and firmware version. The file selector
1608 will start in the directory containing the firmware included
1609 with the AltosUI package. Navigate to the directory containing
1610 the desired firmware if it isn't there.
1613 Next, a small dialog containing the device serial number and
1614 RF calibration values should appear. If these values are
1615 incorrect (possibly due to a corrupted image in the device),
1616 enter the correct values here.
1619 Finally, a dialog containing a progress bar will follow the
1620 programming process.
1623 When programming is complete, the target device will
1624 reboot. Note that if the target device is connected via USB, you
1625 will have to unplug it and then plug it back in for the USB
1626 connection to reset so that you can communicate with the device
1631 <title>Fire Igniter</title>
1633 This activates the igniter circuits in TeleMetrum to help test
1634 recovery systems deployment. Because this command can operate
1635 over the Packet Command Link, you can prepare the rocket as
1636 for flight and then test the recovery system without needing
1637 to snake wires inside the air-frame.
1640 Selecting the 'Fire Igniter' button brings up the usual device
1641 selection dialog. Pick the desired TeleDongle or TeleMetrum
1642 device. This brings up another window which shows the current
1643 continuity test status for both apogee and main charges.
1646 Next, select the desired igniter to fire. This will enable the
1650 Select the 'Arm' button. This enables the 'Fire' button. The
1651 word 'Arm' is replaced by a countdown timer indicating that
1652 you have 10 seconds to press the 'Fire' button or the system
1653 will deactivate, at which point you start over again at
1654 selecting the desired igniter.
1658 <title>Scan Channels</title>
1660 This listens for telemetry packets on all of the configured
1661 frequencies, displaying information about each device it
1662 receives a packet from. You can select which of the three
1663 telemetry formats should be tried; by default, it only listens
1664 for the standard telemetry packets used in v1.0 and later
1669 <title>Load Maps</title>
1671 Before heading out to a new launch site, you can use this to
1672 load satellite images in case you don't have internet
1673 connectivity at the site. This loads a fairly large area
1674 around the launch site, which should cover any flight you're likely to make.
1677 There's a drop-down menu of launch sites we know about; if
1678 your favorites aren't there, please let us know the lat/lon
1679 and name of the site. The contents of this list are actually
1680 downloaded at run-time, so as new sites are sent in, they'll
1681 get automatically added to this list.
1684 If the launch site isn't in the list, you can manually enter the lat/lon values
1687 Clicking the 'Load Map' button will fetch images from Google
1688 Maps; note that Google limits how many images you can fetch at
1689 once, so if you load more than one launch site, you may get
1690 some gray areas in the map which indicate that Google is tired
1691 of sending data to you. Try again later.
1695 <title>Monitor Idle</title>
1697 This brings up a dialog similar to the Monitor Flight UI,
1698 except it works with the altimeter in "idle" mode by sending
1699 query commands to discover the current state rather than
1700 listening for telemetry packets.
1705 <title>Using Altus Metrum Products</title>
1707 <title>Being Legal</title>
1709 First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
1710 other authorization to legally operate the radio transmitters that are part
1715 <title>In the Rocket</title>
1717 In the rocket itself, you just need a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> or
1718 <ulink url="http://www.altusmetrum.org/TeleMini/">TeleMini</ulink> board and
1719 a Li-Po rechargeable battery. An 860mAh battery weighs less than a 9V
1720 alkaline battery, and will run a TeleMetrum for hours.
1721 A 110mAh battery weighs less than a triple A battery and will run a TeleMetrum for
1722 a few hours, or a TeleMini for much (much) longer.
1725 By default, we ship the altimeters with a simple wire antenna. If your
1726 electronics bay or the air-frame it resides within is made of carbon fiber,
1727 which is opaque to RF signals, you may choose to have an SMA connector
1728 installed so that you can run a coaxial cable to an antenna mounted
1729 elsewhere in the rocket.
1733 <title>On the Ground</title>
1735 To receive the data stream from the rocket, you need an antenna and short
1736 feed-line connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> units. The
1737 TeleDongle in turn plugs directly into the USB port on a notebook
1738 computer. Because TeleDongle looks like a simple serial port, your computer
1739 does not require special device drivers... just plug it in.
1742 The GUI tool, AltosUI, is written in Java and runs across
1743 Linux, Mac OS and Windows. There's also a suite of C tools
1744 for Linux which can perform most of the same tasks.
1747 After the flight, you can use the RF link to extract the more detailed data
1748 logged in either TeleMetrum or TeleMini devices, or you can use a mini USB cable to plug into the
1749 TeleMetrum board directly. Pulling out the data without having to open up
1750 the rocket is pretty cool! A USB cable is also how you charge the Li-Po
1751 battery, so you'll want one of those anyway... the same cable used by lots
1752 of digital cameras and other modern electronic stuff will work fine.
1755 If your TeleMetrum-equipped rocket lands out of sight, you may enjoy having a hand-held GPS
1756 receiver, so that you can put in a way-point for the last reported rocket
1757 position before touch-down. This makes looking for your rocket a lot like
1758 Geo-Caching... just go to the way-point and look around starting from there.
1761 You may also enjoy having a ham radio "HT" that covers the 70cm band... you
1762 can use that with your antenna to direction-find the rocket on the ground
1763 the same way you can use a Walston or Beeline tracker. This can be handy
1764 if the rocket is hiding in sage brush or a tree, or if the last GPS position
1765 doesn't get you close enough because the rocket dropped into a canyon, or
1766 the wind is blowing it across a dry lake bed, or something like that... Keith
1767 and Bdale both currently own and use the Yaesu VX-7R at launches.
1770 So, to recap, on the ground the hardware you'll need includes:
1771 <orderedlist inheritnum='inherit' numeration='arabic'>
1773 an antenna and feed-line
1782 optionally, a hand-held GPS receiver
1785 optionally, an HT or receiver covering 435 MHz
1790 The best hand-held commercial directional antennas we've found for radio
1791 direction finding rockets are from
1792 <ulink url="http://www.arrowantennas.com/" >
1795 The 440-3 and 440-5 are both good choices for finding a
1796 TeleMetrum- or TeleMini- equipped rocket when used with a suitable 70cm HT.
1800 <title>Data Analysis</title>
1802 Our software makes it easy to log the data from each flight, both the
1803 telemetry received over the RF link during the flight itself, and the more
1804 complete data log recorded in the flash memory on the altimeter
1805 board. Once this data is on your computer, our post-flight tools make it
1806 easy to quickly get to the numbers everyone wants, like apogee altitude,
1807 max acceleration, and max velocity. You can also generate and view a
1808 standard set of plots showing the altitude, acceleration, and
1809 velocity of the rocket during flight. And you can even export a TeleMetrum data file
1810 usable with Google Maps and Google Earth for visualizing the flight path
1811 in two or three dimensions!
1814 Our ultimate goal is to emit a set of files for each flight that can be
1815 published as a web page per flight, or just viewed on your local disk with
1820 <title>Future Plans</title>
1822 In the future, we intend to offer "companion boards" for the rocket that will
1823 plug in to TeleMetrum to collect additional data, provide more pyro channels,
1824 and so forth. A reference design for a companion board will be documented
1825 soon, and will be compatible with open source Arduino programming tools.
1828 We are also working on the design of a hand-held ground terminal that will
1829 allow monitoring the rocket's status, collecting data during flight, and
1830 logging data after flight without the need for a notebook computer on the
1831 flight line. Particularly since it is so difficult to read most notebook
1832 screens in direct sunlight, we think this will be a great thing to have.
1835 Because all of our work is open, both the hardware designs and the software,
1836 if you have some great idea for an addition to the current Altus Metrum family,
1837 feel free to dive in and help! Or let us know what you'd like to see that
1838 we aren't already working on, and maybe we'll get excited about it too...
1843 <title>Altimeter Installation Recommendations</title>
1845 Building high-power rockets that fly safely is hard enough. Mix
1846 in some sophisticated electronics and a bunch of radio energy
1847 and oftentimes you find few perfect solutions. This chapter
1848 contains some suggestions about how to install Altus Metrum
1849 products into the rocket air-frame, including how to safely and
1850 reliably mix a variety of electronics into the same air-frame.
1853 <title>Mounting the Altimeter</title>
1855 The first consideration is to ensure that the altimeter is
1856 securely fastened to the air-frame. For TeleMetrum, we use
1857 nylon standoffs and nylon screws; they're good to at least 50G
1858 and cannot cause any electrical issues on the board. For
1859 TeleMini, we usually cut small pieces of 1/16" balsa to fit
1860 under the screw holes, and then take 2x56 nylon screws and
1861 screw them through the TeleMini mounting holes, through the
1862 balsa and into the underlying material.
1864 <orderedlist inheritnum='inherit' numeration='arabic'>
1866 Make sure TeleMetrum is aligned precisely along the axis of
1867 acceleration so that the accelerometer can accurately
1868 capture data during the flight.
1871 Watch for any metal touching components on the
1872 board. Shorting out connections on the bottom of the board
1873 can cause the altimeter to fail during flight.
1878 <title>Dealing with the Antenna</title>
1880 The antenna supplied is just a piece of solid, insulated,
1881 wire. If it gets damaged or broken, it can be easily
1882 replaced. It should be kept straight and not cut; bending or
1883 cutting it will change the resonant frequency and/or
1884 impedance, making it a less efficient radiator and thus
1885 reducing the range of the telemetry signal.
1888 Keeping metal away from the antenna will provide better range
1889 and a more even radiation pattern. In most rockets, it's not
1890 entirely possible to isolate the antenna from metal
1891 components; there are often bolts, all-thread and wires from other
1892 electronics to contend with. Just be aware that the more stuff
1893 like this around the antenna, the lower the range.
1896 Make sure the antenna is not inside a tube made or covered
1897 with conducting material. Carbon fiber is the most common
1898 culprit here -- CF is a good conductor and will effectively
1899 shield the antenna, dramatically reducing signal strength and
1900 range. Metallic flake paint is another effective shielding
1901 material which is to be avoided around any antennas.
1904 If the ebay is large enough, it can be convenient to simply
1905 mount the altimeter at one end and stretch the antenna out
1906 inside. Taping the antenna to the sled can keep it straight
1907 under acceleration. If there are metal rods, keep the
1908 antenna as far away as possible.
1911 For a shorter ebay, it's quite practical to have the antenna
1912 run through a bulkhead and into an adjacent bay. Drill a small
1913 hole in the bulkhead, pass the antenna wire through it and
1914 then seal it up with glue or clay. We've also used acrylic
1915 tubing to create a cavity for the antenna wire. This works a
1916 bit better in that the antenna is known to stay straight and
1917 not get folded by recovery components in the bay. Angle the
1918 tubing towards the side wall of the rocket and it ends up
1919 consuming very little space.
1922 If you need to place the antenna at a distance from the
1923 altimeter, you can replace the antenna with an edge-mounted
1924 SMA connector, and then run 50Ω coax from the board to the
1925 antenna. Building a remote antenna is beyond the scope of this
1930 <title>Preserving GPS Reception</title>
1932 The GPS antenna and receiver in TeleMetrum are highly
1933 sensitive and normally have no trouble tracking enough
1934 satellites to provide accurate position information for
1935 recovering the rocket. However, there are many ways to
1936 attenuate the GPS signal.
1937 <orderedlist inheritnum='inherit' numeration='arabic'>
1939 Conductive tubing or coatings. Carbon fiber and metal
1940 tubing, or metallic paint will all dramatically attenuate the
1941 GPS signal. We've never heard of anyone successfully
1942 receiving GPS from inside these materials.
1945 Metal components near the GPS patch antenna. These will
1946 de-tune the patch antenna, changing the resonant frequency
1947 away from the L1 carrier and reduce the effectiveness of the
1948 antenna. You can place as much stuff as you like beneath the
1949 antenna as that's covered with a ground plane. But, keep
1950 wires and metal out from above the patch antenna.
1956 <title>Radio Frequency Interference</title>
1958 Any altimeter will generate RFI; the digital circuits use
1959 high-frequency clocks that spray radio interference across a
1960 wide band. Altusmetrum altimeters generate intentional radio
1961 signals as well, increasing the amount of RF energy around the board.
1964 Rocketry altimeters also use precise sensors measuring air
1965 pressure and acceleration. Tiny changes in voltage can cause
1966 these sensor readings to vary by a huge amount. When the
1967 sensors start mis-reporting data, the altimeter can either
1968 fire the igniters at the wrong time, or not fire them at all.
1971 Voltages are induced when radio frequency energy is
1972 transmitted from one circuit to another. Here are things that
1973 increase the induced voltage and current:
1977 Keep wires from different circuits apart. Moving circuits
1978 further apart will reduce RFI.
1981 Avoid parallel wires from different circuits. The longer two
1982 wires run parallel to one another, the larger the amount of
1983 transferred energy. Cross wires at right angles to reduce
1987 Twist wires from the same circuits. Two wires the same
1988 distance from the transmitter will get the same amount of
1989 induced energy which will then cancel out. Any time you have
1990 a wire pair running together, twist the pair together to
1991 even out distances and reduce RFI. For altimeters, this
1992 includes battery leads, switch hookups and igniter
1996 Avoid resonant lengths. Know what frequencies are present
1997 in the environment and avoid having wire lengths near a
1998 natural resonant length. Altusmetrum products transmit on the
1999 70cm amateur band, so you should avoid lengths that are a
2000 simple ratio of that length; essentially any multiple of 1/4
2001 of the wavelength (17.5cm).
2006 <title>The Barometric Sensor</title>
2008 Altusmetrum altimeters measure altitude with a barometric
2009 sensor, essentially measuring the amount of air above the
2010 rocket to figure out how high it is. A large number of
2011 measurements are taken as the altimeter initializes itself to
2012 figure out the pad altitude. Subsequent measurements are then
2013 used to compute the height above the pad.
2016 To accurately measure atmospheric pressure, the ebay
2017 containing the altimeter must be vented outside the
2018 air-frame. The vent must be placed in a region of linear
2019 airflow, smooth and not in an area of increasing or decreasing
2023 The barometric sensor in the altimeter is quite sensitive to
2024 chemical damage from the products of APCP or BP combustion, so
2025 make sure the ebay is carefully sealed from any compartment
2026 which contains ejection charges or motors.
2030 <title>Ground Testing</title>
2032 The most important aspect of any installation is careful
2033 ground testing. Bringing an air-frame up to the LCO table which
2034 hasn't been ground tested can lead to delays or ejection
2035 charges firing on the pad, or, even worse, a recovery system
2039 Do a 'full systems' test that includes wiring up all igniters
2040 without any BP and turning on all of the electronics in flight
2041 mode. This will catch any mistakes in wiring and any residual
2042 RFI issues that might accidentally fire igniters at the wrong
2043 time. Let the air-frame sit for several minutes, checking for
2044 adequate telemetry signal strength and GPS lock.
2047 Ground test the ejection charges. Prepare the rocket for
2048 flight, loading ejection charges and igniters. Completely
2049 assemble the air-frame and then use the 'Fire Igniters'
2050 interface through a TeleDongle to command each charge to
2051 fire. Make sure the charge is sufficient to robustly separate
2052 the air-frame and deploy the recovery system.
2057 <title>Hardware Specifications</title>
2059 <title>TeleMetrum Specifications</title>
2063 Recording altimeter for model rocketry.
2068 Supports dual deployment (can fire 2 ejection charges).
2073 70cm ham-band transceiver for telemetry down-link.
2078 Barometric pressure sensor good to 45k feet MSL.
2083 1-axis high-g accelerometer for motor characterization, capable of
2084 +/- 50g using default part.
2089 On-board, integrated GPS receiver with 5Hz update rate capability.
2094 On-board 1 megabyte non-volatile memory for flight data storage.
2099 USB interface for battery charging, configuration, and data recovery.
2104 Fully integrated support for Li-Po rechargeable batteries.
2109 Uses Li-Po to fire e-matches, can be modified to support
2110 optional separate pyro battery if needed.
2115 2.75 x 1 inch board designed to fit inside 29mm air-frame coupler tube.
2121 <title>TeleMini Specifications</title>
2125 Recording altimeter for model rocketry.
2130 Supports dual deployment (can fire 2 ejection charges).
2135 70cm ham-band transceiver for telemetry down-link.
2140 Barometric pressure sensor good to 45k feet MSL.
2145 On-board 5 kilobyte non-volatile memory for flight data storage.
2150 RF interface for battery charging, configuration, and data recovery.
2155 Support for Li-Po rechargeable batteries, using an external charger.
2160 Uses Li-Po to fire e-matches, can be modified to support
2161 optional separate pyro battery if needed.
2166 1.5 x .5 inch board designed to fit inside 18mm air-frame coupler tube.
2175 TeleMetrum seems to shut off when disconnected from the
2176 computer. Make sure the battery is adequately charged. Remember the
2177 unit will pull more power than the USB port can deliver before the
2178 GPS enters "locked" mode. The battery charges best when TeleMetrum
2182 It's impossible to stop the TeleDongle when it's in "p" mode, I have
2183 to unplug the USB cable? Make sure you have tried to "escape out" of
2184 this mode. If this doesn't work the reboot procedure for the
2185 TeleDongle *is* to simply unplug it. 'cu' however will retain it's
2186 outgoing buffer IF your "escape out" ('~~') does not work.
2187 At this point using either 'ao-view' (or possibly
2188 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
2192 The amber LED (on the TeleMetrum) lights up when both
2193 battery and USB are connected. Does this mean it's charging?
2194 Yes, the yellow LED indicates the charging at the 'regular' rate.
2195 If the led is out but the unit is still plugged into a USB port,
2196 then the battery is being charged at a 'trickle' rate.
2199 There are no "dit-dah-dah-dit" sound or lights like the manual mentions?
2200 That's the "pad" mode. Weak batteries might be the problem.
2201 It is also possible that the TeleMetrum is horizontal and the output
2202 is instead a "dit-dit" meaning 'idle'. For TeleMini, it's possible that
2203 it received a command packet which would have left it in "pad" mode.
2206 How do I save flight data?
2207 Live telemetry is written to file(s) whenever AltosUI is connected
2208 to the TeleDongle. The file area defaults to ~/TeleMetrum
2209 but is easily changed using the menus in AltosUI. The files that
2210 are written end in '.telem'. The after-flight
2211 data-dumped files will end in .eeprom and represent continuous data
2212 unlike the RF-linked .telem files that are subject to losses
2213 along the RF data path.
2214 See the above instructions on what and how to save the eeprom stored
2215 data after physically retrieving your altimeter. Make sure to save
2216 the on-board data after each flight; while the TeleMetrum can store
2217 multiple flights, you never know when you'll lose the altimeter...
2221 <title>Notes for Older Software</title>
2224 Before AltosUI was written, using Altus Metrum devices required
2225 some finesse with the Linux command line. There was a limited
2226 GUI tool, ao-view, which provided functionality similar to the
2227 Monitor Flight window in AltosUI, but everything else was a
2228 fairly 80's experience. This appendix includes documentation for
2229 using that software.
2233 Both TeleMetrum and TeleDongle can be directly communicated
2234 with using USB ports. The first thing you should try after getting
2235 both units plugged into to your computer's USB port(s) is to run
2236 'ao-list' from a terminal-window to see what port-device-name each
2237 device has been assigned by the operating system.
2238 You will need this information to access the devices via their
2239 respective on-board firmware and data using other command line
2240 programs in the AltOS software suite.
2243 TeleMini can be communicated with through a TeleDongle device
2244 over the radio link. When first booted, TeleMini listens for a
2245 TeleDongle device and if it receives a packet, it goes into
2246 'idle' mode. Otherwise, it goes into 'pad' mode and waits to be
2247 launched. The easiest way to get it talking is to start the
2248 communication link on the TeleDongle and the power up the
2252 To access the device's firmware for configuration you need a terminal
2253 program such as you would use to talk to a modem. The software
2254 authors prefer using the program 'cu' which comes from the UUCP package
2255 on most Unix-like systems such as Linux. An example command line for
2256 cu might be 'cu -l /dev/ttyACM0', substituting the correct number
2257 indicated from running the
2258 ao-list program. Another reasonable terminal program for Linux is
2259 'cutecom'. The default 'escape'
2260 character used by CU (i.e. the character you use to
2261 issue commands to cu itself instead of sending the command as input
2262 to the connected device) is a '~'. You will need this for use in
2263 only two different ways during normal operations. First is to exit
2264 the program by sending a '~.' which is called a 'escape-disconnect'
2265 and allows you to close-out from 'cu'. The
2266 second use will be outlined later.
2269 All of the Altus Metrum devices share the concept of a two level
2270 command set in their firmware.
2271 The first layer has several single letter commands. Once
2272 you are using 'cu' (or 'cutecom') sending (typing) a '?'
2273 returns a full list of these
2274 commands. The second level are configuration sub-commands accessed
2275 using the 'c' command, for
2276 instance typing 'c?' will give you this second level of commands
2277 (all of which require the
2278 letter 'c' to access). Please note that most configuration options
2279 are stored only in Flash memory; TeleDongle doesn't provide any storage
2280 for these options and so they'll all be lost when you unplug it.
2283 Try setting these configuration ('c' or second level menu) values. A good
2284 place to start is by setting your call sign. By default, the boards
2285 use 'N0CALL' which is cute, but not exactly legal!
2286 Spend a few minutes getting comfortable with the units, their
2287 firmware, and 'cu' (or possibly 'cutecom').
2288 For instance, try to send
2289 (type) a 'c r 2' and verify the channel change by sending a 'c s'.
2290 Verify you can connect and disconnect from the units while in your
2291 terminal program by sending the escape-disconnect mentioned above.
2294 Note that the 'reboot' command, which is very useful on the altimeters,
2295 will likely just cause problems with the dongle. The *correct* way
2296 to reset the dongle is just to unplug and re-plug it.
2299 A fun thing to do at the launch site and something you can do while
2300 learning how to use these units is to play with the RF-link access
2301 between an altimeter and the TeleDongle. Be aware that you *must* create
2302 some physical separation between the devices, otherwise the link will
2303 not function due to signal overload in the receivers in each device.
2306 Now might be a good time to take a break and read the rest of this
2307 manual, particularly about the two "modes" that the altimeters
2308 can be placed in. TeleMetrum uses the position of the device when booting
2309 up will determine whether the unit is in "pad" or "idle" mode. TeleMini
2310 enters "idle" mode when it receives a command packet within the first 5 seconds
2311 of being powered up, otherwise it enters "pad" mode.
2314 You can access an altimeter in idle mode from the TeleDongle's USB
2315 connection using the RF link
2316 by issuing a 'p' command to the TeleDongle. Practice connecting and
2317 disconnecting ('~~' while using 'cu') from the altimeter. If
2318 you cannot escape out of the "p" command, (by using a '~~' when in
2319 CU) then it is likely that your kernel has issues. Try a newer version.
2322 Using this RF link allows you to configure the altimeter, test
2323 fire e-matches and igniters from the flight line, check pyro-match
2324 continuity and so forth. You can leave the unit turned on while it
2325 is in 'idle mode' and then place the
2326 rocket vertically on the launch pad, walk away and then issue a
2327 reboot command. The altimeter will reboot and start sending data
2328 having changed to the "pad" mode. If the TeleDongle is not receiving
2329 this data, you can disconnect 'cu' from the TeleDongle using the
2330 procedures mentioned above and THEN connect to the TeleDongle from
2331 inside 'ao-view'. If this doesn't work, disconnect from the
2332 TeleDongle, unplug it, and try again after plugging it back in.
2335 In order to reduce the chance of accidental firing of pyrotechnic
2336 charges, the command to fire a charge is intentionally somewhat
2337 difficult to type, and the built-in help is slightly cryptic to
2338 prevent accidental echoing of characters from the help text back at
2339 the board from firing a charge. The command to fire the apogee
2340 drogue charge is 'i DoIt drogue' and the command to fire the main
2341 charge is 'i DoIt main'.
2344 On TeleMetrum, the GPS will eventually find enough satellites, lock in on them,
2345 and 'ao-view' will both auditorily announce and visually indicate
2347 Now you can launch knowing that you have a good data path and
2348 good satellite lock for flight data and recovery. Remember
2349 you MUST tell ao-view to connect to the TeleDongle explicitly in
2350 order for ao-view to be able to receive data.
2353 The altimeters provide RDF (radio direction finding) tones on
2354 the pad, during descent and after landing. These can be used to
2355 locate the rocket using a directional antenna; the signal
2356 strength providing an indication of the direction from receiver to rocket.
2359 TeleMetrum also provides GPS trekking data, which can further simplify
2360 locating the rocket once it has landed. (The last good GPS data
2361 received before touch-down will be on the data screen of 'ao-view'.)
2364 Once you have recovered the rocket you can download the eeprom
2365 contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over
2366 either a USB cable or over the radio link using TeleDongle.
2367 And by following the man page for 'ao-postflight' you can create
2368 various data output reports, graphs, and even KML data to see the
2369 flight trajectory in Google-earth. (Moving the viewing angle making
2370 sure to connect the yellow lines while in Google-earth is the proper
2374 As for ao-view.... some things are in the menu but don't do anything
2375 very useful. The developers have stopped working on ao-view to focus
2376 on a new, cross-platform ground station program. So ao-view may or
2377 may not be updated in the future. Mostly you just use
2378 the Log and Device menus. It has a wonderful display of the incoming
2379 flight data and I am sure you will enjoy what it has to say to you
2380 once you enable the voice output!
2384 xmlns:xi="http://www.w3.org/2001/XInclude">
2385 <title>Release Notes</title>
2386 <xi:include href="release-notes-1.0.xsl" xpointer="xpointer(/article/*)"/>
2387 <xi:include href="release-notes-0.9.2.xsl" xpointer="xpointer(/article/*)"/>
2388 <xi:include href="release-notes-0.9.xsl" xpointer="xpointer(/article/*)"/>
2389 <xi:include href="release-notes-0.8.xsl" xpointer="xpointer(/article/*)"/>
2390 <xi:include href="release-notes-0.7.1.xsl" xpointer="xpointer(/article/*)"/>
2394 <!-- LocalWords: Altusmetrum
projects / fw / altos / blob