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2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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5 <title>The Altus Metrum System</title>
6 <subtitle>An Owner's Manual for TeleMetrum 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>0.9</revnumber>
40 <date>18 January 2011</date>
42 Updated for software version 0.9. Note that 0.9 represents a
43 telemetry format change, meaning both ends of a link (TeleMetrum and
44 TeleDongle) must be updated or communications will fail.
50 <revnumber>0.8</revnumber>
51 <date>24 November 2010</date>
52 <revremark>Updated for software version 0.8 </revremark>
58 Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing "The
59 Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter
60 Kit" which has turned into the Getting Started chapter in this
61 book. Bob was one of our first customers for a production
62 TeleMetrum, and the enthusiasm that led to his contribution of
63 this section is immensely gratifying and highy appreciated!
66 And thanks to Anthony (AJ) Towns for contributing the
67 AltosUI graphing and site map code and documentation. Free
68 software means that our customers and friends can become our
69 collaborators, and we certainly appreciate this level of
73 Have fun using these products, and we hope to meet all of you
74 out on the rocket flight line somewhere.
77 NAR #87103, TRA #12201
80 NAR #88757, TRA #12200
85 <title>Introduction and Overview</title>
87 Welcome to the Altus Metrum community! Our circuits and software reflect
88 our passion for both hobby rocketry and Free Software. We hope their
89 capabilities and performance will delight you in every way, but by
90 releasing all of our hardware and software designs under open licenses,
91 we also hope to empower you to take as active a role in our collective
95 The focal point of our community is TeleMetrum, a dual deploy altimeter
96 with fully integrated GPS and radio telemetry as standard features, and
97 a "companion interface" that will support optional capabilities in the
101 Complementing TeleMetrum is TeleDongle, a USB to RF interface for
102 communicating with TeleMetrum. Combined with your choice of antenna and
103 notebook computer, TeleDongle and our associated user interface software
104 form a complete ground station capable of logging and displaying in-flight
105 telemetry, aiding rocket recovery, then processing and archiving flight
106 data for analysis and review.
109 More products will be added to the Altus Metrum family over time, and
110 we currently envision that this will be a single, comprehensive manual
111 for the entire product family.
115 <title>Getting Started</title>
117 The first thing to do after you check the inventory of parts in your
118 "starter kit" is to charge the battery by plugging it into the
119 corresponding socket of the TeleMetrum and then using the USB A to
121 cable to plug the Telemetrum into your computer's USB socket. The
122 TeleMetrum circuitry will charge the battery whenever it is plugged
123 in, because the TeleMetrum's on-off switch does NOT control the
124 charging circuitry. When the GPS chip is initially searching for
125 satellites, TeleMetrum will consume more current than it can pull
126 from the usb port, so the battery must be attached in order to get
127 satellite lock. Once GPS is locked, the current consumption goes back
128 down enough to enable charging while
129 running. So it's a good idea to fully charge the battery as your
130 first item of business so there is no issue getting and maintaining
131 satellite lock. The yellow charge indicator led will go out when the
132 battery is nearly full and the charger goes to trickle charge. It
133 can take several hours to fully recharge a deeply discharged battery.
136 The other active device in the starter kit is the TeleDongle USB to
137 RF interface. If you plug it in to your Mac or Linux computer it should
138 "just work", showing up as a serial port device. Windows systems need
139 driver information that is part of the AltOS download to know that the
140 existing USB modem driver will work. If you are using Linux and are
141 having problems, try moving to a fresher kernel (2.6.33 or newer), as
142 the USB serial driver had ugly bugs in some earlier versions.
145 Next you should obtain and install the AltOS utilities. These include
146 the AltosUI ground station program, current firmware images for
147 TeleMetrum and TeleDongle, and a number of standalone utilities that
148 are rarely needed. Pre-built binary packages are available for Debian
149 Linux, Microsoft Windows, and recent MacOSX versions. Full sourcecode
150 and build instructions for some other Linux variants are also available.
151 The latest version may always be downloaded from
152 <ulink url="http://altusmetrum.org/AltOS"/>.
155 Both Telemetrum and TeleDongle can be directly communicated
156 with using USB ports. The first thing you should try after getting
157 both units plugged into to your computer's usb port(s) is to run
158 'ao-list' from a terminal-window to see what port-device-name each
159 device has been assigned by the operating system.
160 You will need this information to access the devices via their
161 respective on-board firmware and data using other command line
162 programs in the AltOS software suite.
165 To access the device's firmware for configuration you need a terminal
166 program such as you would use to talk to a modem. The software
167 authors prefer using the program 'cu' which comes from the UUCP package
168 on most Unix-like systems such as Linux. An example command line for
169 cu might be 'cu -l /dev/ttyACM0', substituting the correct number
170 indicated from running the
171 ao-list program. Another reasonable terminal program for Linux is
172 'cutecom'. The default 'escape'
173 character used by CU (i.e. the character you use to
174 issue commands to cu itself instead of sending the command as input
175 to the connected device) is a '~'. You will need this for use in
176 only two different ways during normal operations. First is to exit
177 the program by sending a '~.' which is called a 'escape-disconnect'
178 and allows you to close-out from 'cu'. The
179 second use will be outlined later.
182 Both TeleMetrum and TeleDongle share the concept of a two level
183 command set in their firmware.
184 The first layer has several single letter commands. Once
185 you are using 'cu' (or 'cutecom') sending (typing) a '?'
186 returns a full list of these
187 commands. The second level are configuration sub-commands accessed
188 using the 'c' command, for
189 instance typing 'c?' will give you this second level of commands
190 (all of which require the
191 letter 'c' to access). Please note that most configuration options
192 are stored only in DataFlash memory, and only TeleMetrum has this
193 memory to save the various values entered like the channel number
194 and your callsign when powered off. TeleDongle requires that you
195 set these each time you plug it in, which ao-view can help with.
198 Try setting these config ('c' or second level menu) values. A good
199 place to start is by setting your call sign. By default, the boards
200 use 'N0CALL' which is cute, but not exactly legal!
201 Spend a few minutes getting comfortable with the units, their
202 firmware, and 'cu' (or possibly 'cutecom').
203 For instance, try to send
204 (type) a 'c r 2' and verify the channel change by sending a 'c s'.
205 Verify you can connect and disconnect from the units while in your
206 terminal program by sending the escape-disconnect mentioned above.
209 Note that the 'reboot' command, which is very useful on TeleMetrum,
210 will likely just cause problems with the dongle. The *correct* way
211 to reset the dongle is just to unplug and re-plug it.
214 A fun thing to do at the launch site and something you can do while
215 learning how to use these units is to play with the rf-link access
216 of the TeleMetrum from the TeleDongle. Be aware that you *must* create
217 some physical separation between the devices, otherwise the link will
218 not function due to signal overload in the receivers in each device.
221 Now might be a good time to take a break and read the rest of this
222 manual, particularly about the two "modes" that the TeleMetrum
223 can be placed in and how the position of the TeleMetrum when booting
224 up will determine whether the unit is in "pad" or "idle" mode.
227 You can access a TeleMetrum in idle mode from the Teledongle's USB
228 connection using the rf link
229 by issuing a 'p' command to the TeleDongle. Practice connecting and
230 disconnecting ('~~' while using 'cu') from the TeleMetrum. If
231 you cannot escape out of the "p" command, (by using a '~~' when in
232 CU) then it is likely that your kernel has issues. Try a newer version.
235 Using this rf link allows you to configure the TeleMetrum, test
236 fire e-matches and igniters from the flight line, check pyro-match
237 continuity and so forth. You can leave the unit turned on while it
238 is in 'idle mode' and then place the
239 rocket vertically on the launch pad, walk away and then issue a
240 reboot command. The TeleMetrum will reboot and start sending data
241 having changed to the "pad" mode. If the TeleDongle is not receiving
242 this data, you can disconnect 'cu' from the Teledongle using the
243 procedures mentioned above and THEN connect to the TeleDongle from
244 inside 'ao-view'. If this doesn't work, disconnect from the
245 TeleDongle, unplug it, and try again after plugging it back in.
248 Eventually the GPS will find enough satellites, lock in on them,
249 and 'ao-view' will both auditorially announce and visually indicate
251 Now you can launch knowing that you have a good data path and
252 good satellite lock for flight data and recovery. Remember
253 you MUST tell ao-view to connect to the TeleDongle explicitly in
254 order for ao-view to be able to receive data.
257 Both RDF (radio direction finding) tones from the TeleMetrum and
258 GPS trekking data are available and together are very useful in
259 locating the rocket once it has landed. (The last good GPS data
260 received before touch-down will be on the data screen of 'ao-view'.)
263 Once you have recovered the rocket you can download the eeprom
264 contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over
265 either a USB cable or over the radio link using TeleDongle.
266 And by following the man page for 'ao-postflight' you can create
267 various data output reports, graphs, and even kml data to see the
268 flight trajectory in google-earth. (Moving the viewing angle making
269 sure to connect the yellow lines while in google-earth is the proper
273 As for ao-view.... some things are in the menu but don't do anything
274 very useful. The developers have stopped working on ao-view to focus
275 on a new, cross-platform ground station program. So ao-view may or
276 may not be updated in the future. Mostly you just use
277 the Log and Device menus. It has a wonderful display of the incoming
278 flight data and I am sure you will enjoy what it has to say to you
279 once you enable the voice output!
284 The altimeter (TeleMetrum) seems to shut off when disconnected from the
285 computer. Make sure the battery is adequately charged. Remember the
286 unit will pull more power than the USB port can deliver before the
287 GPS enters "locked" mode. The battery charges best when TeleMetrum
291 It's impossible to stop the TeleDongle when it's in "p" mode, I have
292 to unplug the USB cable? Make sure you have tried to "escape out" of
293 this mode. If this doesn't work the reboot procedure for the
294 TeleDongle *is* to simply unplug it. 'cu' however will retain it's
295 outgoing buffer IF your "escape out" ('~~') does not work.
296 At this point using either 'ao-view' (or possibly
297 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
301 The amber LED (on the TeleMetrum/altimeter) lights up when both
302 battery and USB are connected. Does this mean it's charging?
303 Yes, the yellow LED indicates the charging at the 'regular' rate.
304 If the led is out but the unit is still plugged into a USB port,
305 then the battery is being charged at a 'trickle' rate.
308 There are no "dit-dah-dah-dit" sound like the manual mentions?
309 That's the "pad" mode. Weak batteries might be the problem.
310 It is also possible that the unit is horizontal and the output
311 is instead a "dit-dit" meaning 'idle'.
314 It's unclear how to use 'ao-view' and other programs when 'cu'
315 is running. You cannot have more than one program connected to
316 the TeleDongle at one time without apparent data loss as the
317 incoming data will not make it to both programs intact.
318 Disconnect whatever programs aren't currently being used.
321 How do I save flight data?
322 Live telemetry is written to file(s) whenever 'ao-view' is connected
323 to the TeleDongle. The file area defaults to ~/altos
324 but is easily changed using the menus in 'ao-view'. The files that
325 are written end in '.telem'. The after-flight
326 data-dumped files will end in .eeprom and represent continuous data
327 unlike the rf-linked .telem files that are subject to the
328 turnarounds/data-packaging time slots in the half-duplex rf data path.
329 See the above instructions on what and how to save the eeprom stored
330 data after physically retrieving your TeleMetrum. Make sure to save
331 the on-board data after each flight, as the current firmware will
332 over-write any previous flight data during a new flight.
337 <title>Specifications</title>
341 Recording altimeter for model rocketry.
346 Supports dual deployment (can fire 2 ejection charges).
351 70cm ham-band transceiver for telemetry downlink.
356 Barometric pressure sensor good to 45k feet MSL.
361 1-axis high-g accelerometer for motor characterization, capable of
362 +/- 50g using default part.
367 On-board, integrated GPS receiver with 5hz update rate capability.
372 On-board 1 megabyte non-volatile memory for flight data storage.
377 USB interface for battery charging, configuration, and data recovery.
382 Fully integrated support for LiPo rechargeable batteries.
387 Uses LiPo to fire e-matches, can be modiied to support
388 optional separate pyro battery if needed.
393 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube.
399 <title>Handling Precautions</title>
401 TeleMetrum is a sophisticated electronic device. When handled gently and
402 properly installed in an airframe, it will deliver impressive results.
403 However, like all electronic devices, there are some precautions you
407 The Lithium Polymer rechargeable batteries used with TeleMetrum have an
408 extraordinary power density. This is great because we can fly with
409 much less battery mass than if we used alkaline batteries or previous
410 generation rechargeable batteries... but if they are punctured
411 or their leads are allowed to short, they can and will release their
413 Thus we recommend that you take some care when handling our batteries
414 and consider giving them some extra protection in your airframe. We
415 often wrap them in suitable scraps of closed-cell packing foam before
416 strapping them down, for example.
419 The TeleMetrum barometric sensor is sensitive to sunlight. In normal
420 mounting situations, it and all of the other surface mount components
421 are "down" towards whatever the underlying mounting surface is, so
422 this is not normally a problem. Please consider this, though, when
423 designing an installation, for example, in a 29mm airframe with a
424 see-through plastic payload bay.
427 The TeleMetrum barometric sensor sampling port must be able to
429 both by not being covered by foam or tape or other materials that might
430 directly block the hole on the top of the sensor, but also by having a
431 suitable static vent to outside air.
434 As with all other rocketry electronics, TeleMetrum must be protected
435 from exposure to corrosive motor exhaust and ejection charge gasses.
439 <title>Hardware Overview</title>
441 TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to
442 fit inside coupler for 29mm airframe tubing, but using it in a tube that
443 small in diameter may require some creativity in mounting and wiring
444 to succeed! The default 1/4
445 wave UHF wire antenna attached to the center of the nose-cone end of
446 the board is about 7 inches long, and wiring for a power switch and
447 the e-matches for apogee and main ejection charges depart from the
448 fin can end of the board. Given all this, an ideal "simple" avionics
449 bay for TeleMetrum should have at least 10 inches of interior length.
452 A typical TeleMetrum installation using the on-board GPS antenna and
453 default wire UHF antenna involves attaching only a suitable
454 Lithium Polymer battery, a single pole switch for power on/off, and
455 two pairs of wires connecting e-matches for the apogee and main ejection
459 By default, we use the unregulated output of the LiPo battery directly
460 to fire ejection charges. This works marvelously with standard
461 low-current e-matches like the J-Tek from MJG Technologies, and with
462 Quest Q2G2 igniters. However, if you
463 want or need to use a separate pyro battery, the board can be factory
464 modified to do so. This involves cutting two traces and adding a jumper
465 in a densely populated part of the board on TeleMetrum v1.0 and v1.1,
466 along with installation of a pyro battery connector at location B2.
469 We offer two choices of pyro and power switch connector, or you can
470 choose neither and solder wires directly to the board. All three choices
471 are reasonable depending on the constraints of your airframe. Our
472 favorite option when there is sufficient room above the board is to use
473 the Tyco pin header with polarization and locking. If you choose this
474 option, you crimp individual wires for the power switch and e-matches
475 into a mating connector, and installing and removing the TeleMetrum
476 board from an airframe is as easy as plugging or unplugging two
477 connectors. If the airframe will not support this much height or if
478 you want to be able to directly attach e-match leads to the board, we
479 offer a screw terminal block. This is very similar to what most other
480 altimeter vendors provide and so may be the most familiar option.
481 You'll need a very small straight blade screwdriver to connect
482 and disconnect the board in this case, such as you might find in a
483 jeweler's screwdriver set. Finally, you can forego both options and
484 solder wires directly to the board, which may be the best choice for
485 minimum diameter and/or minimum mass designs.
488 For most airframes, the integrated GPS antenna and wire UHF antenna are
489 a great combination. However, if you are installing in a carbon-fiber
490 electronics bay which is opaque to RF signals, you may need to use
491 off-board external antennas instead. In this case, you can order
492 TeleMetrum with an SMA connector for the UHF antenna connection, and
493 you can unplug the integrated GPS antenna and select an appropriate
494 off-board GPS antenna with cable terminating in a U.FL connector.
498 <title>System Operation</title>
500 <title>Firmware Modes </title>
502 The AltOS firmware build for TeleMetrum has two fundamental modes,
503 "idle" and "flight". Which of these modes the firmware operates in
504 is determined by the orientation of the rocket (well, actually the
505 board, of course...) at the time power is switched on. If the rocket
506 is "nose up", then TeleMetrum assumes it's on a rail or rod being
507 prepared for launch, so the firmware chooses flight mode. However,
508 if the rocket is more or less horizontal, the firmware instead enters
512 At power on, you will hear three beeps
513 ("S" in Morse code for startup) and then a pause while
514 TeleMetrum completes initialization and self tests, and decides which
518 In flight or "pad" mode, TeleMetrum turns on the GPS system,
520 state machine, goes into transmit-only mode on the RF link sending
521 telemetry, and waits for launch to be detected. Flight mode is
522 indicated by an audible "di-dah-dah-dit" ("P" for pad) on the
524 beeps indicating the state of the pyrotechnic igniter continuity.
525 One beep indicates apogee continuity, two beeps indicate
526 main continuity, three beeps indicate both apogee and main continuity,
527 and one longer "brap" sound indicates no continuity. For a dual
528 deploy flight, make sure you're getting three beeps before launching!
529 For apogee-only or motor eject flights, do what makes sense.
532 In idle mode, you will hear an audible "di-dit" ("I" for idle), and
533 the normal flight state machine is disengaged, thus
534 no ejection charges will fire. TeleMetrum also listens on the RF
535 link when in idle mode for packet mode requests sent from TeleDongle.
536 Commands can be issued to a TeleMetrum in idle mode over either
537 USB or the RF link equivalently.
538 Idle mode is useful for configuring TeleMetrum, for extracting data
539 from the on-board storage chip after flight, and for ground testing
543 One "neat trick" of particular value when TeleMetrum is used with very
544 large airframes, is that you can power the board up while the rocket
545 is horizontal, such that it comes up in idle mode. Then you can
546 raise the airframe to launch position, use a TeleDongle to open
547 a packet connection, and issue a 'reset' command which will cause
548 TeleMetrum to reboot, realize it's now nose-up, and thus choose
549 flight mode. This is much safer than standing on the top step of a
550 rickety step-ladder or hanging off the side of a launch tower with
551 a screw-driver trying to turn on your avionics before installing
558 TeleMetrum includes a complete GPS receiver. See a later section for
559 a brief explanation of how GPS works that will help you understand
560 the information in the telemetry stream. The bottom line is that
561 the TeleMetrum GPS receiver needs to lock onto at least four
562 satellites to obtain a solid 3 dimensional position fix and know
566 TeleMetrum provides backup power to the GPS chip any time a LiPo
567 battery is connected. This allows the receiver to "warm start" on
568 the launch rail much faster than if every power-on were a "cold start"
569 for the GPS receiver. In typical operations, powering up TeleMetrum
570 on the flight line in idle mode while performing final airframe
571 preparation will be sufficient to allow the GPS receiver to cold
572 start and acquire lock. Then the board can be powered down during
573 RSO review and installation on a launch rod or rail. When the board
574 is turned back on, the GPS system should lock very quickly, typically
575 long before igniter installation and return to the flight line are
580 <title>Ground Testing </title>
582 An important aspect of preparing a rocket using electronic deployment
583 for flight is ground testing the recovery system. Thanks
584 to the bi-directional RF link central to the Altus Metrum system,
585 this can be accomplished in a TeleMetrum-equipped rocket without as
586 much work as you may be accustomed to with other systems. It can
590 Just prep the rocket for flight, then power up TeleMetrum while the
591 airframe is horizontal. This will cause the firmware to go into
592 "idle" mode, in which the normal flight state machine is disabled and
593 charges will not fire without manual command. Then, establish an
594 RF packet connection from a TeleDongle-equipped computer using the
595 P command from a safe distance. You can now command TeleMetrum to
596 fire the apogee or main charges to complete your testing.
599 In order to reduce the chance of accidental firing of pyrotechnic
600 charges, the command to fire a charge is intentionally somewhat
601 difficult to type, and the built-in help is slightly cryptic to
602 prevent accidental echoing of characters from the help text back at
603 the board from firing a charge. The command to fire the apogee
604 drogue charge is 'i DoIt drogue' and the command to fire the main
605 charge is 'i DoIt main'.
609 <title>Radio Link </title>
611 The chip our boards are based on incorporates an RF transceiver, but
612 it's not a full duplex system... each end can only be transmitting or
613 receiving at any given moment. So we had to decide how to manage the
617 By design, TeleMetrum firmware listens for an RF connection when
618 it's in "idle mode" (turned on while the rocket is horizontal), which
619 allows us to use the RF link to configure the rocket, do things like
620 ejection tests, and extract data after a flight without having to
621 crack open the airframe. However, when the board is in "flight
622 mode" (turned on when the rocket is vertical) the TeleMetrum only
623 transmits and doesn't listen at all. That's because we want to put
624 ultimate priority on event detection and getting telemetry out of
625 the rocket and out over
626 the RF link in case the rocket crashes and we aren't able to extract
630 We don't use a 'normal packet radio' mode because they're just too
631 inefficient. The GFSK modulation we use is just FSK with the
632 baseband pulses passed through a
633 Gaussian filter before they go into the modulator to limit the
634 transmitted bandwidth. When combined with the hardware forward error
635 correction support in the cc1111 chip, this allows us to have a very
636 robust 38.4 kilobit data link with only 10 milliwatts of transmit power,
637 a whip antenna in the rocket, and a hand-held Yagi on the ground. We've
638 had flights to above 21k feet AGL with good reception, and calculations
639 suggest we should be good to well over 40k feet AGL with a 5-element yagi on
640 the ground. We hope to fly boards to higher altitudes soon, and would
641 of course appreciate customer feedback on performance in higher
646 <title>Configurable Parameters</title>
648 Configuring a TeleMetrum board for flight is very simple. Because we
649 have both acceleration and pressure sensors, there is no need to set
650 a "mach delay", for example. The few configurable parameters can all
651 be set using a simple terminal program over the USB port or RF link
655 <title>Radio Channel</title>
657 Our firmware supports 10 channels. The default channel 0 corresponds
658 to a center frequency of 434.550 Mhz, and channels are spaced every
659 100 khz. Thus, channel 1 is 434.650 Mhz, and channel 9 is 435.550 Mhz.
660 At any given launch, we highly recommend coordinating who will use
661 each channel and when to avoid interference. And of course, both
662 TeleMetrum and TeleDongle must be configured to the same channel to
663 successfully communicate with each other.
666 To set the radio channel, use the 'c r' command, like 'c r 3' to set
668 As with all 'c' sub-commands, follow this with a 'c w' to write the
669 change to the parameter block in the on-board DataFlash chip on
670 your TeleMetrum board if you want the change to stay in place across reboots.
674 <title>Apogee Delay</title>
676 Apogee delay is the number of seconds after TeleMetrum detects flight
677 apogee that the drogue charge should be fired. In most cases, this
678 should be left at the default of 0. However, if you are flying
679 redundant electronics such as for an L3 certification, you may wish
680 to set one of your altimeters to a positive delay so that both
681 primary and backup pyrotechnic charges do not fire simultaneously.
684 To set the apogee delay, use the 'c d' command.
685 As with all 'c' sub-commands, follow this with a 'c w' to write the
686 change to the parameter block in the on-board DataFlash chip.
689 Please note that the TeleMetrum apogee detection algorithm always
690 fires a fraction of a second *after* apogee. If you are also flying
691 an altimeter like the PerfectFlite MAWD, which only supports selecting
692 0 or 1 seconds of apogee delay, you may wish to set the MAWD to 0
693 seconds delay and set the TeleMetrum to fire your backup 2 or 3
694 seconds later to avoid any chance of both charges firing
695 simultaneously. We've flown several airframes this way quite happily,
696 including Keith's successful L3 cert.
700 <title>Main Deployment Altitude</title>
702 By default, TeleMetrum will fire the main deployment charge at an
703 elevation of 250 meters (about 820 feet) above ground. We think this
704 is a good elevation for most airframes, but feel free to change this
705 to suit. In particular, if you are flying two altimeters, you may
707 deployment elevation for the backup altimeter to be something lower
708 than the primary so that both pyrotechnic charges don't fire
712 To set the main deployment altitude, use the 'c m' command.
713 As with all 'c' sub-commands, follow this with a 'c w' to write the
714 change to the parameter block in the on-board DataFlash chip.
719 <title>Calibration</title>
721 There are only two calibrations required for a TeleMetrum board, and
722 only one for TeleDongle.
725 <title>Radio Frequency</title>
727 The radio frequency is synthesized from a clock based on the 48 Mhz
728 crystal on the board. The actual frequency of this oscillator must be
729 measured to generate a calibration constant. While our GFSK modulation
730 bandwidth is wide enough to allow boards to communicate even when
731 their oscillators are not on exactly the same frequency, performance
732 is best when they are closely matched.
733 Radio frequency calibration requires a calibrated frequency counter.
734 Fortunately, once set, the variation in frequency due to aging and
735 temperature changes is small enough that re-calibration by customers
736 should generally not be required.
739 To calibrate the radio frequency, connect the UHF antenna port to a
740 frequency counter, set the board to channel 0, and use the 'C'
741 command to generate a CW carrier. Wait for the transmitter temperature
742 to stabilize and the frequency to settle down.
743 Then, divide 434.550 Mhz by the
744 measured frequency and multiply by the current radio cal value show
745 in the 'c s' command. For an unprogrammed board, the default value
746 is 1186611. Take the resulting integer and program it using the 'c f'
747 command. Testing with the 'C' command again should show a carrier
748 within a few tens of Hertz of the intended frequency.
749 As with all 'c' sub-commands, follow this with a 'c w' to write the
750 change to the parameter block in the on-board DataFlash chip.
754 <title>Accelerometer</title>
756 The accelerometer we use has its own 5 volt power supply and
757 the output must be passed through a resistive voltage divider to match
758 the input of our 3.3 volt ADC. This means that unlike the barometric
759 sensor, the output of the acceleration sensor is not ratiometric to
760 the ADC converter, and calibration is required. We also support the
761 use of any of several accelerometers from a Freescale family that
762 includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity,
763 a simple 2-point calibration yields acceptable results capturing both
764 the different sensitivities and ranges of the different accelerometer
765 parts and any variation in power supply voltages or resistor values
766 in the divider network.
769 To calibrate the acceleration sensor, use the 'c a 0' command. You
770 will be prompted to orient the board vertically with the UHF antenna
771 up and press a key, then to orient the board vertically with the
772 UHF antenna down and press a key.
773 As with all 'c' sub-commands, follow this with a 'c w' to write the
774 change to the parameter block in the on-board DataFlash chip.
777 The +1g and -1g calibration points are included in each telemetry
778 frame and are part of the header extracted by ao-dumplog after flight.
779 Note that we always store and return raw ADC samples for each
780 sensor... nothing is permanently "lost" or "damaged" if the
784 In the unlikely event an accel cal that goes badly, it is possible
785 that TeleMetrum may always come up in 'pad mode' and as such not be
786 listening to either the USB or radio interfaces. If that happens,
787 there is a special hook in the firmware to force the board back
788 in to 'idle mode' so you can re-do the cal. To use this hook, you
789 just need to ground the SPI clock pin at power-on. This pin is
790 available as pin 2 on the 8-pin companion connector, and pin 1 is
791 ground. So either carefully install a fine-gauge wire jumper
792 between the two pins closest to the index hole end of the 8-pin
793 connector, or plug in the programming cable to the 8-pin connector
794 and use a small screwdriver or similar to short the two pins closest
795 to the index post on the 4-pin end of the programming cable, and
796 power up the board. It should come up in 'idle mode' (two beeps).
804 <title>Updating Device Firmware</title>
806 The big conceptual thing to realize is that you have to use a
807 TeleDongle as a programmer to update a TeleMetrum, and vice versa.
808 Due to limited memory resources in the cc1111, we don't support
809 programming either unit directly over USB.
812 You may wish to begin by ensuring you have current firmware images.
813 These are distributed as part of the AltOS software bundle that
814 also includes the AltosUI ground station program. Newer ground
815 station versions typically work fine with older firmware versions,
816 so you don't need to update your devices just to try out new
817 software features. You can always download the most recent
818 version from <ulink url="http://www.altusmetrum.org/AltOS/"/>.
821 We recommend updating TeleMetrum first, before updating TeleDongle.
824 <title>Updating TeleMetrum Firmware</title>
825 <orderedlist inheritnum='inherit' numeration='arabic'>
827 Find the 'programming cable' that you got as part of the starter
828 kit, that has a red 8-pin MicroMaTch connector on one end and a
829 red 4-pin MicroMaTch connector on the other end.
832 Take the 2 screws out of the TeleDongle case to get access
833 to the circuit board.
836 Plug the 8-pin end of the programming cable to the
837 matching connector on the TeleDongle, and the 4-pin end to the
838 matching connector on the TeleMetrum.
839 Note that each MicroMaTch connector has an alignment pin that
840 goes through a hole in the PC board when you have the cable
844 Attach a battery to the TeleMetrum board.
847 Plug the TeleDongle into your computer's USB port, and power
851 Run AltosUI, and select 'Flash Image' from the File menu.
854 Pick the TeleDongle device from the list, identifying it as the
858 Select the image you want put on the TeleMetrum, which should have a
859 name in the form telemetrum-v1.0-0.7.1.ihx. It should be visible
860 in the default directory, if not you may have to poke around
861 your system to find it.
864 Make sure the configuration parameters are reasonable
865 looking. If the serial number and/or RF configuration
866 values aren't right, you'll need to change them.
869 Hit the 'OK' button and the software should proceed to flash
870 the TeleMetrum with new firmware, showing a progress bar.
873 Confirm that the TeleMetrum board seems to have updated ok, which you
874 can do by plugging in to it over USB and using a terminal program
875 to connect to the board and issue the 'v' command to check
879 If something goes wrong, give it another try.
884 <title>Updating TeleDongle Firmware</title>
886 Updating TeleDongle's firmware is just like updating TeleMetrum
887 firmware, but you switch which board is the programmer and which
888 is the programming target.
890 <orderedlist inheritnum='inherit' numeration='arabic'>
892 Find the 'programming cable' that you got as part of the starter
893 kit, that has a red 8-pin MicroMaTch connector on one end and a
894 red 4-pin MicroMaTch connector on the other end.
897 Find the USB cable that you got as part of the starter kit, and
898 plug the "mini" end in to the mating connector on TeleMetrum.
901 Take the 2 screws out of the TeleDongle case to get access
902 to the circuit board.
905 Plug the 8-pin end of the programming cable to the (latching)
906 matching connector on the TeleMetrum, and the 4-pin end to the
907 matching connector on the TeleDongle.
908 Note that each MicroMaTch connector has an alignment pin that
909 goes through a hole in the PC board when you have the cable
913 Attach a battery to the TeleMetrum board.
916 Plug both TeleMetrum and TeleDongle into your computer's USB
917 ports, and power up the TeleMetrum.
920 Run AltosUI, and select 'Flash Image' from the File menu.
923 Pick the TeleMetrum device from the list, identifying it as the
927 Select the image you want put on the TeleDongle, which should have a
928 name in the form teledongle-v0.2-0.7.1.ihx. It should be visible
929 in the default directory, if not you may have to poke around
930 your system to find it.
933 Make sure the configuration parameters are reasonable
934 looking. If the serial number and/or RF configuration
935 values aren't right, you'll need to change them. The TeleDongle
936 serial number is on the "bottom" of the circuit board, and can
937 usually be read through the translucent blue plastic case without
938 needing to remove the board from the case.
941 Hit the 'OK' button and the software should proceed to flash
942 the TeleDongle with new firmware, showing a progress bar.
945 Confirm that the TeleDongle board seems to have updated ok, which you
946 can do by plugging in to it over USB and using a terminal program
947 to connect to the board and issue the 'v' command to check
948 the version, etc. Once you're happy, remove the programming cable
949 and put the cover back on the TeleDongle.
952 If something goes wrong, give it another try.
956 Be careful removing the programming cable from the locking 8-pin
957 connector on TeleMetrum. You'll need a fingernail or perhaps a thin
958 screwdriver or knife blade to gently pry the locking ears out
959 slightly to extract the connector. We used a locking connector on
960 TeleMetrum to help ensure that the cabling to companion boards
961 used in a rocket don't ever come loose accidentally in flight.
971 <title>AltosUI</title>
973 The AltosUI program provides a graphical user interface for
974 interacting with the Altus Metrum product family, including
975 TeleMetrum and TeleDongle. AltosUI can monitor telemetry data,
976 configure TeleMetrum and TeleDongle devices and many other
977 tasks. The primary interface window provides a selection of
978 buttons, one for each major activity in the system. This manual
979 is split into chapters, each of which documents one of the tasks
980 provided from the top-level toolbar.
983 <title>Packet Command Mode</title>
984 <subtitle>Controlling TeleMetrum Over The Radio Link</subtitle>
986 One of the unique features of the Altus Metrum environment is
987 the ability to create a two way command link between TeleDongle
988 and TeleMetrum using the digital radio transceivers built into
989 each device. This allows you to interact with TeleMetrum from
990 afar, as if it were directly connected to the computer.
993 Any operation which can be performed with TeleMetrum
994 can either be done with TeleMetrum directly connected to
995 the computer via the USB cable, or through the packet
996 link. Simply select the appropriate TeleDongle device when
997 the list of devices is presented and AltosUI will use packet
1001 One oddity in the current interface is how AltosUI selects the
1002 channel for packet mode communications. Instead of providing
1003 an interface to specifically configure the channel, it uses
1004 whatever channel was most recently selected for the target
1005 TeleDongle device in Monitor Flight mode. If you haven't ever
1006 used that mode with the TeleDongle in question, select the
1007 Monitor Flight button from the top level UI, pick the
1008 appropriate TeleDongle device. Once the flight monitoring
1009 window is open, select the desired channel and then close it
1010 down again. All Packet Command Mode operations will now use
1016 Save Flight Data—Recover flight data from the rocket without
1022 Configure TeleMetrum—Reset apogee delays or main deploy
1023 heights to respond to changing launch conditions. You can
1024 also 'reboot' the TeleMetrum device. Use this to remotely
1025 enable the flight computer by turning TeleMetrum on while
1026 horizontal, then once the airframe is oriented for launch,
1027 you can reboot TeleMetrum and have it restart in pad mode
1028 without having to climb the scary ladder.
1033 Fire Igniters—Test your deployment charges without snaking
1034 wires out through holes in the airframe. Simply assembly the
1035 rocket as if for flight with the apogee and main charges
1036 loaded, then remotely command TeleMetrum to fire the
1042 Packet command mode uses the same RF channels as telemetry
1043 mode. Configure the desired TeleDongle channel using the
1044 flight monitor window channel selector and then close that
1045 window before performing the desired operation.
1048 TeleMetrum only enables packet command mode in 'idle' mode, so
1049 make sure you have TeleMetrum lying horizontally when you turn
1050 it on. Otherwise, TeleMetrum will start in 'pad' mode ready for
1051 flight and will not be listening for command packets from TeleDongle.
1054 When packet command mode is enabled, you can monitor the link
1055 by watching the lights on the TeleDongle and TeleMetrum
1056 devices. The red LED will flash each time TeleDongle or
1057 TeleMetrum transmit a packet while the green LED will light up
1058 on TeleDongle while it is waiting to receive a packet from
1063 <title>Monitor Flight</title>
1064 <subtitle>Receive, Record and Display Telemetry Data</subtitle>
1066 Selecting this item brings up a dialog box listing all of the
1067 connected TeleDongle devices. When you choose one of these,
1068 AltosUI will create a window to display telemetry data as
1069 received by the selected TeleDongle device.
1072 All telemetry data received are automatically recorded in
1073 suitable log files. The name of the files includes the current
1074 date and rocket serial and flight numbers.
1077 The radio channel being monitored by the TeleDongle device is
1078 displayed at the top of the window. You can configure the
1079 channel by clicking on the channel box and selecting the desired
1080 channel. AltosUI remembers the last channel selected for each
1081 TeleDongle and selects that automatically the next time you use
1085 Below the TeleDongle channel selector, the window contains a few
1086 significant pieces of information about the TeleMetrum providing
1087 the telemetry data stream:
1091 <para>The TeleMetrum callsign</para>
1094 <para>The TeleMetrum serial number</para>
1097 <para>The flight number. Each TeleMetrum remembers how many
1103 The rocket flight state. Each flight passes through several
1104 states including Pad, Boost, Fast, Coast, Drogue, Main and
1110 The Received Signal Strength Indicator value. This lets
1111 you know how strong a signal TeleDongle is receiving. The
1112 radio inside TeleDongle operates down to about -99dBm;
1113 weaker signals may not be receiveable. The packet link uses
1114 error correction and detection techniques which prevent
1115 incorrect data from being reported.
1120 Finally, the largest portion of the window contains a set of
1121 tabs, each of which contain some information about the rocket.
1122 They're arranged in 'flight order' so that as the flight
1123 progresses, the selected tab automatically switches to display
1124 data relevant to the current state of the flight. You can select
1125 other tabs at any time. The final 'table' tab contains all of
1126 the telemetry data in one place.
1129 <title>Launch Pad</title>
1131 The 'Launch Pad' tab shows information used to decide when the
1132 rocket is ready for flight. The first elements include red/green
1133 indicators, if any of these is red, you'll want to evaluate
1134 whether the rocket is ready to launch:
1138 Battery Voltage. This indicates whether the LiPo battery
1139 powering the TeleMetrum has sufficient charge to last for
1140 the duration of the flight. A value of more than
1141 3.7V is required for a 'GO' status.
1146 Apogee Igniter Voltage. This indicates whether the apogee
1147 igniter has continuity. If the igniter has a low
1148 resistance, then the voltage measured here will be close
1149 to the LiPo battery voltage. A value greater than 3.2V is
1150 required for a 'GO' status.
1155 Main Igniter Voltage. This indicates whether the main
1156 igniter has continuity. If the igniter has a low
1157 resistance, then the voltage measured here will be close
1158 to the LiPo battery voltage. A value greater than 3.2V is
1159 required for a 'GO' status.
1164 GPS Locked. This indicates whether the GPS receiver is
1165 currently able to compute position information. GPS requires
1166 at least 4 satellites to compute an accurate position.
1171 GPS Ready. This indicates whether GPS has reported at least
1172 10 consecutive positions without losing lock. This ensures
1173 that the GPS receiver has reliable reception from the
1179 The LaunchPad tab also shows the computed launch pad position
1180 and altitude, averaging many reported positions to improve the
1181 accuracy of the fix.
1186 <title>Ascent</title>
1188 This tab is shown during Boost, Fast and Coast
1189 phases. The information displayed here helps monitor the
1190 rocket as it heads towards apogee.
1193 The height, speed and acceleration are shown along with the
1194 maxium values for each of them. This allows you to quickly
1195 answer the most commonly asked questions you'll hear during
1199 The current latitude and longitude reported by the GPS are
1200 also shown. Note that under high acceleration, these values
1201 may not get updated as the GPS receiver loses position
1202 fix. Once the rocket starts coasting, the receiver should
1203 start reporting position again.
1206 Finally, the current igniter voltages are reported as in the
1207 Launch Pad tab. This can help diagnose deployment failures
1208 caused by wiring which comes loose under high acceleration.
1212 <title>Descent</title>
1214 Once the rocket has reached apogee and (we hope) activated the
1215 apogee charge, attention switches to tracking the rocket on
1216 the way back to the ground, and for dual-deploy flights,
1217 waiting for the main charge to fire.
1220 To monitor whether the apogee charge operated correctly, the
1221 current descent rate is reported along with the current
1222 height. Good descent rates generally range from 15-30m/s.
1225 To help locate the rocket in the sky, use the elevation and
1226 bearing information to figure out where to look. Elevation is
1227 in degrees above the horizon. Bearing is reported in degrees
1228 relative to true north. Range can help figure out how big the
1229 rocket will appear. Note that all of these values are relative
1230 to the pad location. If the elevation is near 90°, the rocket
1231 is over the pad, not over you.
1234 Finally, the igniter voltages are reported in this tab as
1235 well, both to monitor the main charge as well as to see what
1236 the status of the apogee charge is.
1240 <title>Landed</title>
1242 Once the rocket is on the ground, attention switches to
1243 recovery. While the radio signal is generally lost once the
1244 rocket is on the ground, the last reported GPS position is
1245 generally within a short distance of the actual landing location.
1248 The last reported GPS position is reported both by
1249 latitude and longitude as well as a bearing and distance from
1250 the launch pad. The distance should give you a good idea of
1251 whether you'll want to walk or hitch a ride. Take the reported
1252 latitude and longitude and enter them into your handheld GPS
1253 unit and have that compute a track to the landing location.
1256 Finally, the maximum height, speed and acceleration reported
1257 during the flight are displayed for your admiring observers.
1261 <title>Site Map</title>
1263 When the rocket gets a GPS fix, the Site Map tab will map
1264 the rocket's position to make it easier for you to locate the
1265 rocket, both while it is in the air, and when it has landed. The
1266 rocket's state is indicated by colour: white for pad, red for
1267 boost, pink for fast, yellow for coast, light blue for drogue,
1268 dark blue for main, and black for landed.
1271 The map's scale is approximately 3m (10ft) per pixel. The map
1272 can be dragged using the left mouse button. The map will attempt
1273 to keep the rocket roughly centred while data is being received.
1276 Images are fetched automatically via the Google Maps Static API,
1277 and are cached for reuse. If map images cannot be downloaded,
1278 the rocket's path will be traced on a dark grey background
1284 <title>Save Flight Data</title>
1286 TeleMetrum records flight data to its internal flash memory.
1287 This data is recorded at a much higher rate than the telemetry
1288 system can handle, and is not subject to radio drop-outs. As
1289 such, it provides a more complete and precise record of the
1290 flight. The 'Save Flight Data' button allows you to read the
1291 flash memory and write it to disk.
1294 Clicking on the 'Save Flight Data' button brings up a list of
1295 connected TeleMetrum and TeleDongle devices. If you select a
1296 TeleMetrum device, the flight data will be downloaded from that
1297 device directly. If you select a TeleDongle device, flight data
1298 will be downloaded from a TeleMetrum device connected via the
1299 packet command link to the specified TeleDongle. See the chapter
1300 on Packet Command Mode for more information about this.
1303 After the device has been selected, a dialog showing the
1304 flight data saved in the device will be shown allowing you to
1305 select which flights to download and which to delete. With
1306 version 0.9 or newer firmware, you must erase flights in order
1307 for the space they consume to be reused by another
1308 flight. This prevents you from accidentally losing flight data
1309 if you neglect to download data before flying again. Note that
1310 if there is no more space available in the device, then no
1311 data will be recorded for a flight.
1314 The filename for each flight log is computed automatically
1315 from the recorded flight date, TeleMetrum serial number and
1316 flight number information.
1320 <title>Replay Flight</title>
1322 Select this button and you are prompted to select a flight
1323 record file, either a .telem file recording telemetry data or a
1324 .eeprom file containing flight data saved from the TeleMetrum
1328 Once a flight record is selected, the flight monitor interface
1329 is displayed and the flight is re-enacted in real time. Check
1330 the Monitor Flight chapter above to learn how this window operates.
1334 <title>Graph Data</title>
1336 Select this button and you are prompted to select a flight
1337 record file, either a .telem file recording telemetry data or a
1338 .eeprom file containing flight data saved from the TeleMetrum
1342 Once a flight record is selected, the acceleration (blue),
1343 velocity (green) and altitude (red) of the flight are plotted and
1344 displayed, measured in metric units.
1347 The graph can be zoomed into a particular area by clicking and
1348 dragging down and to the right. Once zoomed, the graph can be
1349 reset by clicking and dragging up and to the left. Holding down
1350 control and clicking and dragging allows the graph to be panned.
1351 The right mouse button causes a popup menu to be displayed, giving
1352 you the option save or print the plot.
1355 Note that telemetry files will generally produce poor graphs
1356 due to the lower sampling rate and missed telemetry packets,
1357 and will also often have significant amounts of data received
1358 while the rocket was waiting on the pad. Use saved flight data
1359 for graphing where possible.
1363 <title>Export Data</title>
1365 This tool takes the raw data files and makes them available for
1366 external analysis. When you select this button, you are prompted to select a flight
1367 data file (either .eeprom or .telem will do, remember that
1368 .eeprom files contain higher resolution and more continuous
1369 data). Next, a second dialog appears which is used to select
1370 where to write the resulting file. It has a selector to choose
1371 between CSV and KML file formats.
1374 <title>Comma Separated Value Format</title>
1376 This is a text file containing the data in a form suitable for
1377 import into a spreadsheet or other external data analysis
1378 tool. The first few lines of the file contain the version and
1379 configuration information from the TeleMetrum device, then
1380 there is a single header line which labels all of the
1381 fields. All of these lines start with a '#' character which
1382 most tools can be configured to skip over.
1385 The remaining lines of the file contain the data, with each
1386 field separated by a comma and at least one space. All of
1387 the sensor values are converted to standard units, with the
1388 barometric data reported in both pressure, altitude and
1389 height above pad units.
1393 <title>Keyhole Markup Language (for Google Earth)</title>
1395 This is the format used by
1396 Googleearth to provide an overlay within that
1397 application. With this, you can use Googleearth to see the
1398 whole flight path in 3D.
1403 <title>Configure TeleMetrum</title>
1405 Select this button and then select either a TeleMetrum or
1406 TeleDongle Device from the list provided. Selecting a TeleDongle
1407 device will use Packet Comamnd Mode to configure remote
1408 TeleMetrum device. Learn how to use this in the Packet Command
1412 The first few lines of the dialog provide information about the
1413 connected TeleMetrum device, including the product name,
1414 software version and hardware serial number. Below that are the
1415 individual configuration entries.
1418 At the bottom of the dialog, there are four buttons:
1423 Save. This writes any changes to the TeleMetrum
1424 configuration parameter block in flash memory. If you don't
1425 press this button, any changes you make will be lost.
1430 Reset. This resets the dialog to the most recently saved values,
1431 erasing any changes you have made.
1436 Reboot. This reboots the TeleMetrum device. Use this to
1437 switch from idle to pad mode by rebooting once the rocket is
1438 oriented for flight.
1443 Close. This closes the dialog. Any unsaved changes will be
1449 The rest of the dialog contains the parameters to be configured.
1452 <title>Main Deploy Altitude</title>
1454 This sets the altitude (above the recorded pad altitude) at
1455 which the 'main' igniter will fire. The drop-down menu shows
1456 some common values, but you can edit the text directly and
1457 choose whatever you like. If the apogee charge fires below
1458 this altitude, then the main charge will fire two seconds
1459 after the apogee charge fires.
1463 <title>Apogee Delay</title>
1465 When flying redundant electronics, it's often important to
1466 ensure that multiple apogee charges don't fire at precisely
1467 the same time as that can overpressurize the apogee deployment
1468 bay and cause a structural failure of the airframe. The Apogee
1469 Delay parameter tells the flight computer to fire the apogee
1470 charge a certain number of seconds after apogee has been
1475 <title>Radio Channel</title>
1477 This configures which of the 10 radio channels to use for both
1478 telemetry and packet command mode. Note that if you set this
1479 value via packet command mode, you will have to reconfigure
1480 the TeleDongle channel before you will be able to use packet
1485 <title>Radio Calibration</title>
1487 The radios in every Altus Metrum device are calibrated at the
1488 factory to ensure that they transmit and receive on the
1489 specified frequency for each channel. You can adjust that
1490 calibration by changing this value. To change the TeleDongle's
1491 calibration, you must reprogram the unit completely.
1495 <title>Callsign</title>
1497 This sets the callsign included in each telemetry packet. Set this
1498 as needed to conform to your local radio regulations.
1502 <title>Maximum Flight Log Size</title>
1504 This sets the space (in kilobytes) allocated for each flight
1505 log. The available space will be divided into chunks of this
1506 size. A smaller value will allow more flights to be stored,
1507 a larger value will record data from longer flights.
1510 During ascent, TeleMetrum records barometer and
1511 accelerometer values 100 times per second, other analog
1512 information (voltages and temperature) 6 times per second
1513 and GPS data once per second. During descent, the non-GPS
1514 data is recorded 1/10th as often. Each barometer +
1515 accelerometer record takes 8 bytes.
1518 The default, 192kB, will store over 200 seconds of data at
1519 the ascent rate, or over 2000 seconds of data at the descent
1520 rate. That's plenty for most flights. This leaves enough
1521 storage for five flights in a 1MB system, or 10 flights in a
1525 The configuration block takes the last available block of
1526 memory, on v1.0 boards that's just 256 bytes. However, the
1527 flash part on the v1.1 boards uses 64kB for each block.
1532 <title>Configure AltosUI</title>
1534 This button presents a dialog so that you can configure the AltosUI global settings.
1537 <title>Voice Settings</title>
1539 AltosUI provides voice annoucements during flight so that you
1540 can keep your eyes on the sky and still get information about
1541 the current flight status. However, sometimes you don't want
1546 <para>Enable—turns all voice announcements on and off</para>
1550 Test Voice—Plays a short message allowing you to verify
1551 that the audio systme is working and the volume settings
1558 <title>Log Directory</title>
1560 AltosUI logs all telemetry data and saves all TeleMetrum flash
1561 data to this directory. This directory is also used as the
1562 staring point when selecting data files for display or export.
1565 Click on the directory name to bring up a directory choosing
1566 dialog, select a new directory and click 'Select Directory' to
1567 change where AltosUI reads and writes data files.
1571 <title>Callsign</title>
1573 This value is used in command packet mode and is transmitted
1574 in each packet sent from TeleDongle and received from
1575 TeleMetrum. It is not used in telemetry mode as that transmits
1576 packets only from TeleMetrum to TeleDongle. Configure this
1577 with the AltosUI operators callsign as needed to comply with
1578 your local radio regulations.
1582 <title>Serial Debug</title>
1584 This causes all communication with a connected device to be
1585 dumped to the console from which AltosUI was started. If
1586 you've started it from an icon or menu entry, the output
1587 will simply be discarded. This mode can be useful to debug
1588 various serial communication issues.
1593 <title>Flash Image</title>
1595 This reprograms any Altus Metrum device by using a TeleMetrum or
1596 TeleDongle as a programming dongle. Please read the directions
1597 for connecting the programming cable in the main TeleMetrum
1598 manual before reading these instructions.
1601 Once you have the programmer and target devices connected,
1602 push the 'Flash Image' button. That will present a dialog box
1603 listing all of the connected devices. Carefully select the
1604 programmer device, not the device to be programmed.
1607 Next, select the image to flash to the device. These are named
1608 with the product name and firmware version. The file selector
1609 will start in the directory containing the firmware included
1610 with the AltosUI package. Navigate to the directory containing
1611 the desired firmware if it isn't there.
1614 Next, a small dialog containing the device serial number and
1615 RF calibration values should appear. If these values are
1616 incorrect (possibly due to a corrupted image in the device),
1617 enter the correct values here.
1620 Finally, a dialog containing a progress bar will follow the
1621 programming process.
1624 When programming is complete, the target device will
1625 reboot. Note that if the target device is connected via USB, you
1626 will have to unplug it and then plug it back in for the USB
1627 connection to reset so that you can communicate with the device
1632 <title>Fire Igniter</title>
1634 This activates the igniter circuits in TeleMetrum to help test
1635 recovery systems deployment. Because this command can operate
1636 over the Packet Command Link, you can prepare the rocket as
1637 for flight and then test the recovery system without needing
1638 to snake wires inside the airframe.
1641 Selecting the 'Fire Igniter' button brings up the usual device
1642 selection dialog. Pick the desired TeleDongle or TeleMetrum
1643 device. This brings up another window which shows the current
1644 continutity test status for both apogee and main charges.
1647 Next, select the desired igniter to fire. This will enable the
1651 Select the 'Arm' button. This enables the 'Fire' button. The
1652 word 'Arm' is replaced by a countdown timer indicating that
1653 you have 10 seconds to press the 'Fire' button or the system
1654 will deactivate, at which point you start over again at
1655 selecting the desired igniter.
1660 <title>Using Altus Metrum Products</title>
1662 <title>Being Legal</title>
1664 First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
1665 other authorization to legally operate the radio transmitters that are part
1670 <title>In the Rocket</title>
1672 In the rocket itself, you just need a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> board and
1673 a LiPo rechargeable battery. An 860mAh battery weighs less than a 9V
1674 alkaline battery, and will run a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> for hours.
1677 By default, we ship TeleMetrum with a simple wire antenna. If your
1678 electronics bay or the airframe it resides within is made of carbon fiber,
1679 which is opaque to RF signals, you may choose to have an SMA connector
1680 installed so that you can run a coaxial cable to an antenna mounted
1681 elsewhere in the rocket.
1685 <title>On the Ground</title>
1687 To receive the data stream from the rocket, you need an antenna and short
1688 feedline connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> units. The
1689 TeleDongle in turn plugs directly into the USB port on a notebook
1690 computer. Because TeleDongle looks like a simple serial port, your computer
1691 does not require special device drivers... just plug it in.
1694 The GUI tool, AltosUI, is written in Java and runs across
1695 Linux, Mac OS and Windows. There's also a suite of C tools
1696 for Linux which can perform most of the same tasks.
1699 After the flight, you can use the RF link to extract the more detailed data
1700 logged in the rocket, or you can use a mini USB cable to plug into the
1701 TeleMetrum board directly. Pulling out the data without having to open up
1702 the rocket is pretty cool! A USB cable is also how you charge the LiPo
1703 battery, so you'll want one of those anyway... the same cable used by lots
1704 of digital cameras and other modern electronic stuff will work fine.
1707 If your rocket lands out of sight, you may enjoy having a hand-held GPS
1708 receiver, so that you can put in a waypoint for the last reported rocket
1709 position before touch-down. This makes looking for your rocket a lot like
1710 Geo-Cacheing... just go to the waypoint and look around starting from there.
1713 You may also enjoy having a ham radio "HT" that covers the 70cm band... you
1714 can use that with your antenna to direction-find the rocket on the ground
1715 the same way you can use a Walston or Beeline tracker. This can be handy
1716 if the rocket is hiding in sage brush or a tree, or if the last GPS position
1717 doesn't get you close enough because the rocket dropped into a canyon, or
1718 the wind is blowing it across a dry lake bed, or something like that... Keith
1719 and Bdale both currently own and use the Yaesu VX-7R at launches.
1722 So, to recap, on the ground the hardware you'll need includes:
1723 <orderedlist inheritnum='inherit' numeration='arabic'>
1725 an antenna and feedline
1734 optionally, a handheld GPS receiver
1737 optionally, an HT or receiver covering 435 Mhz
1742 The best hand-held commercial directional antennas we've found for radio
1743 direction finding rockets are from
1744 <ulink url="http://www.arrowantennas.com/" >
1747 The 440-3 and 440-5 are both good choices for finding a
1748 TeleMetrum-equipped rocket when used with a suitable 70cm HT.
1752 <title>Data Analysis</title>
1754 Our software makes it easy to log the data from each flight, both the
1755 telemetry received over the RF link during the flight itself, and the more
1756 complete data log recorded in the DataFlash memory on the TeleMetrum
1757 board. Once this data is on your computer, our postflight tools make it
1758 easy to quickly get to the numbers everyone wants, like apogee altitude,
1759 max acceleration, and max velocity. You can also generate and view a
1760 standard set of plots showing the altitude, acceleration, and
1761 velocity of the rocket during flight. And you can even export a data file
1762 useable with Google Maps and Google Earth for visualizing the flight path
1763 in two or three dimensions!
1766 Our ultimate goal is to emit a set of files for each flight that can be
1767 published as a web page per flight, or just viewed on your local disk with
1772 <title>Future Plans</title>
1774 In the future, we intend to offer "companion boards" for the rocket that will
1775 plug in to TeleMetrum to collect additional data, provide more pyro channels,
1776 and so forth. A reference design for a companion board will be documented
1777 soon, and will be compatible with open source Arduino programming tools.
1780 We are also working on the design of a hand-held ground terminal that will
1781 allow monitoring the rocket's status, collecting data during flight, and
1782 logging data after flight without the need for a notebook computer on the
1783 flight line. Particularly since it is so difficult to read most notebook
1784 screens in direct sunlight, we think this will be a great thing to have.
1787 Because all of our work is open, both the hardware designs and the software,
1788 if you have some great idea for an addition to the current Altus Metrum family,
1789 feel free to dive in and help! Or let us know what you'd like to see that
1790 we aren't already working on, and maybe we'll get excited about it too...