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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>0.9.2</revnumber>
40 <date>19 March 2011</date>
42 Updated for software version 0.9.2. This version has minor
43 updates to the AltosUI code to fix graphing on Mac OS X and
44 make flight data download more reliable. It is otherwise
45 completely compatible with version 0.9.
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.
60 <revnumber>0.8</revnumber>
61 <date>24 November 2010</date>
62 <revremark>Updated for software version 0.8 </revremark>
68 Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing "The
69 Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter
70 Kit" which has turned into the Getting Started chapter in this
71 book. Bob was one of our first customers for a production
72 TeleMetrum, and the enthusiasm that led to his contribution of
73 this section is immensely gratifying and highy appreciated!
76 And thanks to Anthony (AJ) Towns for contributing the
77 AltosUI graphing and site map code and documentation. Free
78 software means that our customers and friends can become our
79 collaborators, and we certainly appreciate this level of
83 Have fun using these products, and we hope to meet all of you
84 out on the rocket flight line somewhere.
87 NAR #87103, TRA #12201
90 NAR #88757, TRA #12200
95 <title>Introduction and Overview</title>
97 Welcome to the Altus Metrum community! Our circuits and software reflect
98 our passion for both hobby rocketry and Free Software. We hope their
99 capabilities and performance will delight you in every way, but by
100 releasing all of our hardware and software designs under open licenses,
101 we also hope to empower you to take as active a role in our collective
105 The focal point of our community is TeleMetrum, a dual deploy altimeter
106 with fully integrated GPS and radio telemetry as standard features, and
107 a "companion interface" that will support optional capabilities in the
111 Complementing TeleMetrum is TeleDongle, a USB to RF interface for
112 communicating with TeleMetrum. Combined with your choice of antenna and
113 notebook computer, TeleDongle and our associated user interface software
114 form a complete ground station capable of logging and displaying in-flight
115 telemetry, aiding rocket recovery, then processing and archiving flight
116 data for analysis and review.
119 More products will be added to the Altus Metrum family over time, and
120 we currently envision that this will be a single, comprehensive manual
121 for the entire product family.
125 <title>Getting Started</title>
127 The first thing to do after you check the inventory of parts in your
128 "starter kit" is to charge the battery by plugging it into the
129 corresponding socket of the TeleMetrum and then using the USB A to
131 cable to plug the Telemetrum into your computer's USB socket. The
132 TeleMetrum circuitry will charge the battery whenever it is plugged
133 in, because the TeleMetrum's on-off switch does NOT control the
134 charging circuitry. When the GPS chip is initially searching for
135 satellites, TeleMetrum will consume more current than it can pull
136 from the usb port, so the battery must be attached in order to get
137 satellite lock. Once GPS is locked, the current consumption goes back
138 down enough to enable charging while
139 running. So it's a good idea to fully charge the battery as your
140 first item of business so there is no issue getting and maintaining
141 satellite lock. The yellow charge indicator led will go out when the
142 battery is nearly full and the charger goes to trickle charge. It
143 can take several hours to fully recharge a deeply discharged battery.
146 The other active device in the starter kit is the TeleDongle USB to
147 RF interface. If you plug it in to your Mac or Linux computer it should
148 "just work", showing up as a serial port device. Windows systems need
149 driver information that is part of the AltOS download to know that the
150 existing USB modem driver will work. If you are using Linux and are
151 having problems, try moving to a fresher kernel (2.6.33 or newer), as
152 the USB serial driver had ugly bugs in some earlier versions.
155 Next you should obtain and install the AltOS utilities. These include
156 the AltosUI ground station program, current firmware images for
157 TeleMetrum and TeleDongle, and a number of standalone utilities that
158 are rarely needed. Pre-built binary packages are available for Debian
159 Linux, Microsoft Windows, and recent MacOSX versions. Full sourcecode
160 and build instructions for some other Linux variants are also available.
161 The latest version may always be downloaded from
162 <ulink url="http://altusmetrum.org/AltOS"/>.
165 Both Telemetrum and TeleDongle can be directly communicated
166 with using USB ports. The first thing you should try after getting
167 both units plugged into to your computer's usb port(s) is to run
168 'ao-list' from a terminal-window to see what port-device-name each
169 device has been assigned by the operating system.
170 You will need this information to access the devices via their
171 respective on-board firmware and data using other command line
172 programs in the AltOS software suite.
175 To access the device's firmware for configuration you need a terminal
176 program such as you would use to talk to a modem. The software
177 authors prefer using the program 'cu' which comes from the UUCP package
178 on most Unix-like systems such as Linux. An example command line for
179 cu might be 'cu -l /dev/ttyACM0', substituting the correct number
180 indicated from running the
181 ao-list program. Another reasonable terminal program for Linux is
182 'cutecom'. The default 'escape'
183 character used by CU (i.e. the character you use to
184 issue commands to cu itself instead of sending the command as input
185 to the connected device) is a '~'. You will need this for use in
186 only two different ways during normal operations. First is to exit
187 the program by sending a '~.' which is called a 'escape-disconnect'
188 and allows you to close-out from 'cu'. The
189 second use will be outlined later.
192 Both TeleMetrum and TeleDongle share the concept of a two level
193 command set in their firmware.
194 The first layer has several single letter commands. Once
195 you are using 'cu' (or 'cutecom') sending (typing) a '?'
196 returns a full list of these
197 commands. The second level are configuration sub-commands accessed
198 using the 'c' command, for
199 instance typing 'c?' will give you this second level of commands
200 (all of which require the
201 letter 'c' to access). Please note that most configuration options
202 are stored only in DataFlash memory, and only TeleMetrum has this
203 memory to save the various values entered like the channel number
204 and your callsign when powered off. TeleDongle requires that you
205 set these each time you plug it in, which ao-view can help with.
208 Try setting these config ('c' or second level menu) values. A good
209 place to start is by setting your call sign. By default, the boards
210 use 'N0CALL' which is cute, but not exactly legal!
211 Spend a few minutes getting comfortable with the units, their
212 firmware, and 'cu' (or possibly 'cutecom').
213 For instance, try to send
214 (type) a 'c r 2' and verify the channel change by sending a 'c s'.
215 Verify you can connect and disconnect from the units while in your
216 terminal program by sending the escape-disconnect mentioned above.
219 Note that the 'reboot' command, which is very useful on TeleMetrum,
220 will likely just cause problems with the dongle. The *correct* way
221 to reset the dongle is just to unplug and re-plug it.
224 A fun thing to do at the launch site and something you can do while
225 learning how to use these units is to play with the rf-link access
226 of the TeleMetrum from the TeleDongle. Be aware that you *must* create
227 some physical separation between the devices, otherwise the link will
228 not function due to signal overload in the receivers in each device.
231 Now might be a good time to take a break and read the rest of this
232 manual, particularly about the two "modes" that the TeleMetrum
233 can be placed in and how the position of the TeleMetrum when booting
234 up will determine whether the unit is in "pad" or "idle" mode.
237 You can access a TeleMetrum in idle mode from the Teledongle's USB
238 connection using the rf link
239 by issuing a 'p' command to the TeleDongle. Practice connecting and
240 disconnecting ('~~' while using 'cu') from the TeleMetrum. If
241 you cannot escape out of the "p" command, (by using a '~~' when in
242 CU) then it is likely that your kernel has issues. Try a newer version.
245 Using this rf link allows you to configure the TeleMetrum, test
246 fire e-matches and igniters from the flight line, check pyro-match
247 continuity and so forth. You can leave the unit turned on while it
248 is in 'idle mode' and then place the
249 rocket vertically on the launch pad, walk away and then issue a
250 reboot command. The TeleMetrum will reboot and start sending data
251 having changed to the "pad" mode. If the TeleDongle is not receiving
252 this data, you can disconnect 'cu' from the Teledongle using the
253 procedures mentioned above and THEN connect to the TeleDongle from
254 inside 'ao-view'. If this doesn't work, disconnect from the
255 TeleDongle, unplug it, and try again after plugging it back in.
258 Eventually the GPS will find enough satellites, lock in on them,
259 and 'ao-view' will both auditorially announce and visually indicate
261 Now you can launch knowing that you have a good data path and
262 good satellite lock for flight data and recovery. Remember
263 you MUST tell ao-view to connect to the TeleDongle explicitly in
264 order for ao-view to be able to receive data.
267 Both RDF (radio direction finding) tones from the TeleMetrum and
268 GPS trekking data are available and together are very useful in
269 locating the rocket once it has landed. (The last good GPS data
270 received before touch-down will be on the data screen of 'ao-view'.)
273 Once you have recovered the rocket you can download the eeprom
274 contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over
275 either a USB cable or over the radio link using TeleDongle.
276 And by following the man page for 'ao-postflight' you can create
277 various data output reports, graphs, and even kml data to see the
278 flight trajectory in google-earth. (Moving the viewing angle making
279 sure to connect the yellow lines while in google-earth is the proper
283 As for ao-view.... some things are in the menu but don't do anything
284 very useful. The developers have stopped working on ao-view to focus
285 on a new, cross-platform ground station program. So ao-view may or
286 may not be updated in the future. Mostly you just use
287 the Log and Device menus. It has a wonderful display of the incoming
288 flight data and I am sure you will enjoy what it has to say to you
289 once you enable the voice output!
294 The altimeter (TeleMetrum) seems to shut off when disconnected from the
295 computer. Make sure the battery is adequately charged. Remember the
296 unit will pull more power than the USB port can deliver before the
297 GPS enters "locked" mode. The battery charges best when TeleMetrum
301 It's impossible to stop the TeleDongle when it's in "p" mode, I have
302 to unplug the USB cable? Make sure you have tried to "escape out" of
303 this mode. If this doesn't work the reboot procedure for the
304 TeleDongle *is* to simply unplug it. 'cu' however will retain it's
305 outgoing buffer IF your "escape out" ('~~') does not work.
306 At this point using either 'ao-view' (or possibly
307 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed
311 The amber LED (on the TeleMetrum/altimeter) lights up when both
312 battery and USB are connected. Does this mean it's charging?
313 Yes, the yellow LED indicates the charging at the 'regular' rate.
314 If the led is out but the unit is still plugged into a USB port,
315 then the battery is being charged at a 'trickle' rate.
318 There are no "dit-dah-dah-dit" sound like the manual mentions?
319 That's the "pad" mode. Weak batteries might be the problem.
320 It is also possible that the unit is horizontal and the output
321 is instead a "dit-dit" meaning 'idle'.
324 It's unclear how to use 'ao-view' and other programs when 'cu'
325 is running. You cannot have more than one program connected to
326 the TeleDongle at one time without apparent data loss as the
327 incoming data will not make it to both programs intact.
328 Disconnect whatever programs aren't currently being used.
331 How do I save flight data?
332 Live telemetry is written to file(s) whenever 'ao-view' is connected
333 to the TeleDongle. The file area defaults to ~/altos
334 but is easily changed using the menus in 'ao-view'. The files that
335 are written end in '.telem'. The after-flight
336 data-dumped files will end in .eeprom and represent continuous data
337 unlike the rf-linked .telem files that are subject to the
338 turnarounds/data-packaging time slots in the half-duplex rf data path.
339 See the above instructions on what and how to save the eeprom stored
340 data after physically retrieving your TeleMetrum. Make sure to save
341 the on-board data after each flight, as the current firmware will
342 over-write any previous flight data during a new flight.
347 <title>Specifications</title>
351 Recording altimeter for model rocketry.
356 Supports dual deployment (can fire 2 ejection charges).
361 70cm ham-band transceiver for telemetry downlink.
366 Barometric pressure sensor good to 45k feet MSL.
371 1-axis high-g accelerometer for motor characterization, capable of
372 +/- 50g using default part.
377 On-board, integrated GPS receiver with 5hz update rate capability.
382 On-board 1 megabyte non-volatile memory for flight data storage.
387 USB interface for battery charging, configuration, and data recovery.
392 Fully integrated support for LiPo rechargeable batteries.
397 Uses LiPo to fire e-matches, can be modiied to support
398 optional separate pyro battery if needed.
403 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube.
409 <title>Handling Precautions</title>
411 TeleMetrum is a sophisticated electronic device. When handled gently and
412 properly installed in an airframe, it will deliver impressive results.
413 However, like all electronic devices, there are some precautions you
417 The Lithium Polymer rechargeable batteries used with TeleMetrum have an
418 extraordinary power density. This is great because we can fly with
419 much less battery mass than if we used alkaline batteries or previous
420 generation rechargeable batteries... but if they are punctured
421 or their leads are allowed to short, they can and will release their
423 Thus we recommend that you take some care when handling our batteries
424 and consider giving them some extra protection in your airframe. We
425 often wrap them in suitable scraps of closed-cell packing foam before
426 strapping them down, for example.
429 The TeleMetrum barometric sensor is sensitive to sunlight. In normal
430 mounting situations, it and all of the other surface mount components
431 are "down" towards whatever the underlying mounting surface is, so
432 this is not normally a problem. Please consider this, though, when
433 designing an installation, for example, in a 29mm airframe with a
434 see-through plastic payload bay.
437 The TeleMetrum barometric sensor sampling port must be able to
439 both by not being covered by foam or tape or other materials that might
440 directly block the hole on the top of the sensor, but also by having a
441 suitable static vent to outside air.
444 As with all other rocketry electronics, TeleMetrum must be protected
445 from exposure to corrosive motor exhaust and ejection charge gasses.
449 <title>Hardware Overview</title>
451 TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to
452 fit inside coupler for 29mm airframe tubing, but using it in a tube that
453 small in diameter may require some creativity in mounting and wiring
454 to succeed! The default 1/4
455 wave UHF wire antenna attached to the center of the nose-cone end of
456 the board is about 7 inches long, and wiring for a power switch and
457 the e-matches for apogee and main ejection charges depart from the
458 fin can end of the board. Given all this, an ideal "simple" avionics
459 bay for TeleMetrum should have at least 10 inches of interior length.
462 A typical TeleMetrum installation using the on-board GPS antenna and
463 default wire UHF antenna involves attaching only a suitable
464 Lithium Polymer battery, a single pole switch for power on/off, and
465 two pairs of wires connecting e-matches for the apogee and main ejection
469 By default, we use the unregulated output of the LiPo battery directly
470 to fire ejection charges. This works marvelously with standard
471 low-current e-matches like the J-Tek from MJG Technologies, and with
472 Quest Q2G2 igniters. However, if you
473 want or need to use a separate pyro battery, the board can be factory
474 modified to do so. This involves cutting two traces and adding a jumper
475 in a densely populated part of the board on TeleMetrum v1.0 and v1.1,
476 along with installation of a pyro battery connector at location B2.
479 We offer two choices of pyro and power switch connector, or you can
480 choose neither and solder wires directly to the board. All three choices
481 are reasonable depending on the constraints of your airframe. Our
482 favorite option when there is sufficient room above the board is to use
483 the Tyco pin header with polarization and locking. If you choose this
484 option, you crimp individual wires for the power switch and e-matches
485 into a mating connector, and installing and removing the TeleMetrum
486 board from an airframe is as easy as plugging or unplugging two
487 connectors. If the airframe will not support this much height or if
488 you want to be able to directly attach e-match leads to the board, we
489 offer a screw terminal block. This is very similar to what most other
490 altimeter vendors provide and so may be the most familiar option.
491 You'll need a very small straight blade screwdriver to connect
492 and disconnect the board in this case, such as you might find in a
493 jeweler's screwdriver set. Finally, you can forego both options and
494 solder wires directly to the board, which may be the best choice for
495 minimum diameter and/or minimum mass designs.
498 For most airframes, the integrated GPS antenna and wire UHF antenna are
499 a great combination. However, if you are installing in a carbon-fiber
500 electronics bay which is opaque to RF signals, you may need to use
501 off-board external antennas instead. In this case, you can order
502 TeleMetrum with an SMA connector for the UHF antenna connection, and
503 you can unplug the integrated GPS antenna and select an appropriate
504 off-board GPS antenna with cable terminating in a U.FL connector.
508 <title>System Operation</title>
510 <title>Firmware Modes </title>
512 The AltOS firmware build for TeleMetrum has two fundamental modes,
513 "idle" and "flight". Which of these modes the firmware operates in
514 is determined by the orientation of the rocket (well, actually the
515 board, of course...) at the time power is switched on. If the rocket
516 is "nose up", then TeleMetrum assumes it's on a rail or rod being
517 prepared for launch, so the firmware chooses flight mode. However,
518 if the rocket is more or less horizontal, the firmware instead enters
522 At power on, you will hear three beeps
523 ("S" in Morse code for startup) and then a pause while
524 TeleMetrum completes initialization and self tests, and decides which
528 In flight or "pad" mode, TeleMetrum turns on the GPS system,
530 state machine, goes into transmit-only mode on the RF link sending
531 telemetry, and waits for launch to be detected. Flight mode is
532 indicated by an audible "di-dah-dah-dit" ("P" for pad) on the
534 beeps indicating the state of the pyrotechnic igniter continuity.
535 One beep indicates apogee continuity, two beeps indicate
536 main continuity, three beeps indicate both apogee and main continuity,
537 and one longer "brap" sound indicates no continuity. For a dual
538 deploy flight, make sure you're getting three beeps before launching!
539 For apogee-only or motor eject flights, do what makes sense.
542 In idle mode, you will hear an audible "di-dit" ("I" for idle), and
543 the normal flight state machine is disengaged, thus
544 no ejection charges will fire. TeleMetrum also listens on the RF
545 link when in idle mode for packet mode requests sent from TeleDongle.
546 Commands can be issued to a TeleMetrum in idle mode over either
547 USB or the RF link equivalently.
548 Idle mode is useful for configuring TeleMetrum, for extracting data
549 from the on-board storage chip after flight, and for ground testing
553 One "neat trick" of particular value when TeleMetrum is used with very
554 large airframes, is that you can power the board up while the rocket
555 is horizontal, such that it comes up in idle mode. Then you can
556 raise the airframe to launch position, use a TeleDongle to open
557 a packet connection, and issue a 'reset' command which will cause
558 TeleMetrum to reboot, realize it's now nose-up, and thus choose
559 flight mode. This is much safer than standing on the top step of a
560 rickety step-ladder or hanging off the side of a launch tower with
561 a screw-driver trying to turn on your avionics before installing
568 TeleMetrum includes a complete GPS receiver. See a later section for
569 a brief explanation of how GPS works that will help you understand
570 the information in the telemetry stream. The bottom line is that
571 the TeleMetrum GPS receiver needs to lock onto at least four
572 satellites to obtain a solid 3 dimensional position fix and know
576 TeleMetrum provides backup power to the GPS chip any time a LiPo
577 battery is connected. This allows the receiver to "warm start" on
578 the launch rail much faster than if every power-on were a "cold start"
579 for the GPS receiver. In typical operations, powering up TeleMetrum
580 on the flight line in idle mode while performing final airframe
581 preparation will be sufficient to allow the GPS receiver to cold
582 start and acquire lock. Then the board can be powered down during
583 RSO review and installation on a launch rod or rail. When the board
584 is turned back on, the GPS system should lock very quickly, typically
585 long before igniter installation and return to the flight line are
590 <title>Ground Testing </title>
592 An important aspect of preparing a rocket using electronic deployment
593 for flight is ground testing the recovery system. Thanks
594 to the bi-directional RF link central to the Altus Metrum system,
595 this can be accomplished in a TeleMetrum-equipped rocket without as
596 much work as you may be accustomed to with other systems. It can
600 Just prep the rocket for flight, then power up TeleMetrum while the
601 airframe is horizontal. This will cause the firmware to go into
602 "idle" mode, in which the normal flight state machine is disabled and
603 charges will not fire without manual command. Then, establish an
604 RF packet connection from a TeleDongle-equipped computer using the
605 P command from a safe distance. You can now command TeleMetrum to
606 fire the apogee or main charges to complete your testing.
609 In order to reduce the chance of accidental firing of pyrotechnic
610 charges, the command to fire a charge is intentionally somewhat
611 difficult to type, and the built-in help is slightly cryptic to
612 prevent accidental echoing of characters from the help text back at
613 the board from firing a charge. The command to fire the apogee
614 drogue charge is 'i DoIt drogue' and the command to fire the main
615 charge is 'i DoIt main'.
619 <title>Radio Link </title>
621 The chip our boards are based on incorporates an RF transceiver, but
622 it's not a full duplex system... each end can only be transmitting or
623 receiving at any given moment. So we had to decide how to manage the
627 By design, TeleMetrum firmware listens for an RF connection when
628 it's in "idle mode" (turned on while the rocket is horizontal), which
629 allows us to use the RF link to configure the rocket, do things like
630 ejection tests, and extract data after a flight without having to
631 crack open the airframe. However, when the board is in "flight
632 mode" (turned on when the rocket is vertical) the TeleMetrum only
633 transmits and doesn't listen at all. That's because we want to put
634 ultimate priority on event detection and getting telemetry out of
635 the rocket and out over
636 the RF link in case the rocket crashes and we aren't able to extract
640 We don't use a 'normal packet radio' mode because they're just too
641 inefficient. The GFSK modulation we use is just FSK with the
642 baseband pulses passed through a
643 Gaussian filter before they go into the modulator to limit the
644 transmitted bandwidth. When combined with the hardware forward error
645 correction support in the cc1111 chip, this allows us to have a very
646 robust 38.4 kilobit data link with only 10 milliwatts of transmit power,
647 a whip antenna in the rocket, and a hand-held Yagi on the ground. We've
648 had flights to above 21k feet AGL with good reception, and calculations
649 suggest we should be good to well over 40k feet AGL with a 5-element yagi on
650 the ground. We hope to fly boards to higher altitudes soon, and would
651 of course appreciate customer feedback on performance in higher
656 <title>Configurable Parameters</title>
658 Configuring a TeleMetrum board for flight is very simple. Because we
659 have both acceleration and pressure sensors, there is no need to set
660 a "mach delay", for example. The few configurable parameters can all
661 be set using a simple terminal program over the USB port or RF link
665 <title>Radio Channel</title>
667 Our firmware supports 10 channels. The default channel 0 corresponds
668 to a center frequency of 434.550 Mhz, and channels are spaced every
669 100 khz. Thus, channel 1 is 434.650 Mhz, and channel 9 is 435.550 Mhz.
670 At any given launch, we highly recommend coordinating who will use
671 each channel and when to avoid interference. And of course, both
672 TeleMetrum and TeleDongle must be configured to the same channel to
673 successfully communicate with each other.
676 To set the radio channel, use the 'c r' command, like 'c r 3' to set
678 As with all 'c' sub-commands, follow this with a 'c w' to write the
679 change to the parameter block in the on-board DataFlash chip on
680 your TeleMetrum board if you want the change to stay in place across reboots.
684 <title>Apogee Delay</title>
686 Apogee delay is the number of seconds after TeleMetrum detects flight
687 apogee that the drogue charge should be fired. In most cases, this
688 should be left at the default of 0. However, if you are flying
689 redundant electronics such as for an L3 certification, you may wish
690 to set one of your altimeters to a positive delay so that both
691 primary and backup pyrotechnic charges do not fire simultaneously.
694 To set the apogee delay, use the 'c d' command.
695 As with all 'c' sub-commands, follow this with a 'c w' to write the
696 change to the parameter block in the on-board DataFlash chip.
699 Please note that the TeleMetrum apogee detection algorithm always
700 fires a fraction of a second *after* apogee. If you are also flying
701 an altimeter like the PerfectFlite MAWD, which only supports selecting
702 0 or 1 seconds of apogee delay, you may wish to set the MAWD to 0
703 seconds delay and set the TeleMetrum to fire your backup 2 or 3
704 seconds later to avoid any chance of both charges firing
705 simultaneously. We've flown several airframes this way quite happily,
706 including Keith's successful L3 cert.
710 <title>Main Deployment Altitude</title>
712 By default, TeleMetrum will fire the main deployment charge at an
713 elevation of 250 meters (about 820 feet) above ground. We think this
714 is a good elevation for most airframes, but feel free to change this
715 to suit. In particular, if you are flying two altimeters, you may
717 deployment elevation for the backup altimeter to be something lower
718 than the primary so that both pyrotechnic charges don't fire
722 To set the main deployment altitude, use the 'c m' command.
723 As with all 'c' sub-commands, follow this with a 'c w' to write the
724 change to the parameter block in the on-board DataFlash chip.
729 <title>Calibration</title>
731 There are only two calibrations required for a TeleMetrum board, and
732 only one for TeleDongle.
735 <title>Radio Frequency</title>
737 The radio frequency is synthesized from a clock based on the 48 Mhz
738 crystal on the board. The actual frequency of this oscillator must be
739 measured to generate a calibration constant. While our GFSK modulation
740 bandwidth is wide enough to allow boards to communicate even when
741 their oscillators are not on exactly the same frequency, performance
742 is best when they are closely matched.
743 Radio frequency calibration requires a calibrated frequency counter.
744 Fortunately, once set, the variation in frequency due to aging and
745 temperature changes is small enough that re-calibration by customers
746 should generally not be required.
749 To calibrate the radio frequency, connect the UHF antenna port to a
750 frequency counter, set the board to channel 0, and use the 'C'
751 command to generate a CW carrier. Wait for the transmitter temperature
752 to stabilize and the frequency to settle down.
753 Then, divide 434.550 Mhz by the
754 measured frequency and multiply by the current radio cal value show
755 in the 'c s' command. For an unprogrammed board, the default value
756 is 1186611. Take the resulting integer and program it using the 'c f'
757 command. Testing with the 'C' command again should show a carrier
758 within a few tens of Hertz of the intended frequency.
759 As with all 'c' sub-commands, follow this with a 'c w' to write the
760 change to the parameter block in the on-board DataFlash chip.
764 <title>Accelerometer</title>
766 The accelerometer we use has its own 5 volt power supply and
767 the output must be passed through a resistive voltage divider to match
768 the input of our 3.3 volt ADC. This means that unlike the barometric
769 sensor, the output of the acceleration sensor is not ratiometric to
770 the ADC converter, and calibration is required. We also support the
771 use of any of several accelerometers from a Freescale family that
772 includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity,
773 a simple 2-point calibration yields acceptable results capturing both
774 the different sensitivities and ranges of the different accelerometer
775 parts and any variation in power supply voltages or resistor values
776 in the divider network.
779 To calibrate the acceleration sensor, use the 'c a 0' command. You
780 will be prompted to orient the board vertically with the UHF antenna
781 up and press a key, then to orient the board vertically with the
782 UHF antenna down and press a key.
783 As with all 'c' sub-commands, follow this with a 'c w' to write the
784 change to the parameter block in the on-board DataFlash chip.
787 The +1g and -1g calibration points are included in each telemetry
788 frame and are part of the header extracted by ao-dumplog after flight.
789 Note that we always store and return raw ADC samples for each
790 sensor... nothing is permanently "lost" or "damaged" if the
794 In the unlikely event an accel cal that goes badly, it is possible
795 that TeleMetrum may always come up in 'pad mode' and as such not be
796 listening to either the USB or radio interfaces. If that happens,
797 there is a special hook in the firmware to force the board back
798 in to 'idle mode' so you can re-do the cal. To use this hook, you
799 just need to ground the SPI clock pin at power-on. This pin is
800 available as pin 2 on the 8-pin companion connector, and pin 1 is
801 ground. So either carefully install a fine-gauge wire jumper
802 between the two pins closest to the index hole end of the 8-pin
803 connector, or plug in the programming cable to the 8-pin connector
804 and use a small screwdriver or similar to short the two pins closest
805 to the index post on the 4-pin end of the programming cable, and
806 power up the board. It should come up in 'idle mode' (two beeps).
814 <title>Updating Device Firmware</title>
816 The big conceptual thing to realize is that you have to use a
817 TeleDongle as a programmer to update a TeleMetrum, and vice versa.
818 Due to limited memory resources in the cc1111, we don't support
819 programming either unit directly over USB.
822 You may wish to begin by ensuring you have current firmware images.
823 These are distributed as part of the AltOS software bundle that
824 also includes the AltosUI ground station program. Newer ground
825 station versions typically work fine with older firmware versions,
826 so you don't need to update your devices just to try out new
827 software features. You can always download the most recent
828 version from <ulink url="http://www.altusmetrum.org/AltOS/"/>.
831 We recommend updating TeleMetrum first, before updating TeleDongle.
834 <title>Updating TeleMetrum Firmware</title>
835 <orderedlist inheritnum='inherit' numeration='arabic'>
837 Find the 'programming cable' that you got as part of the starter
838 kit, that has a red 8-pin MicroMaTch connector on one end and a
839 red 4-pin MicroMaTch connector on the other end.
842 Take the 2 screws out of the TeleDongle case to get access
843 to the circuit board.
846 Plug the 8-pin end of the programming cable to the
847 matching connector on the TeleDongle, and the 4-pin end to the
848 matching connector on the TeleMetrum.
849 Note that each MicroMaTch connector has an alignment pin that
850 goes through a hole in the PC board when you have the cable
854 Attach a battery to the TeleMetrum board.
857 Plug the TeleDongle into your computer's USB port, and power
861 Run AltosUI, and select 'Flash Image' from the File menu.
864 Pick the TeleDongle device from the list, identifying it as the
868 Select the image you want put on the TeleMetrum, which should have a
869 name in the form telemetrum-v1.0-0.7.1.ihx. It should be visible
870 in the default directory, if not you may have to poke around
871 your system to find it.
874 Make sure the configuration parameters are reasonable
875 looking. If the serial number and/or RF configuration
876 values aren't right, you'll need to change them.
879 Hit the 'OK' button and the software should proceed to flash
880 the TeleMetrum with new firmware, showing a progress bar.
883 Confirm that the TeleMetrum board seems to have updated ok, which you
884 can do by plugging in to it over USB and using a terminal program
885 to connect to the board and issue the 'v' command to check
889 If something goes wrong, give it another try.
894 <title>Updating TeleDongle Firmware</title>
896 Updating TeleDongle's firmware is just like updating TeleMetrum
897 firmware, but you switch which board is the programmer and which
898 is the programming target.
900 <orderedlist inheritnum='inherit' numeration='arabic'>
902 Find the 'programming cable' that you got as part of the starter
903 kit, that has a red 8-pin MicroMaTch connector on one end and a
904 red 4-pin MicroMaTch connector on the other end.
907 Find the USB cable that you got as part of the starter kit, and
908 plug the "mini" end in to the mating connector on TeleMetrum.
911 Take the 2 screws out of the TeleDongle case to get access
912 to the circuit board.
915 Plug the 8-pin end of the programming cable to the (latching)
916 matching connector on the TeleMetrum, and the 4-pin end to the
917 matching connector on the TeleDongle.
918 Note that each MicroMaTch connector has an alignment pin that
919 goes through a hole in the PC board when you have the cable
923 Attach a battery to the TeleMetrum board.
926 Plug both TeleMetrum and TeleDongle into your computer's USB
927 ports, and power up the TeleMetrum.
930 Run AltosUI, and select 'Flash Image' from the File menu.
933 Pick the TeleMetrum device from the list, identifying it as the
937 Select the image you want put on the TeleDongle, which should have a
938 name in the form teledongle-v0.2-0.7.1.ihx. It should be visible
939 in the default directory, if not you may have to poke around
940 your system to find it.
943 Make sure the configuration parameters are reasonable
944 looking. If the serial number and/or RF configuration
945 values aren't right, you'll need to change them. The TeleDongle
946 serial number is on the "bottom" of the circuit board, and can
947 usually be read through the translucent blue plastic case without
948 needing to remove the board from the case.
951 Hit the 'OK' button and the software should proceed to flash
952 the TeleDongle with new firmware, showing a progress bar.
955 Confirm that the TeleDongle board seems to have updated ok, which you
956 can do by plugging in to it over USB and using a terminal program
957 to connect to the board and issue the 'v' command to check
958 the version, etc. Once you're happy, remove the programming cable
959 and put the cover back on the TeleDongle.
962 If something goes wrong, give it another try.
966 Be careful removing the programming cable from the locking 8-pin
967 connector on TeleMetrum. You'll need a fingernail or perhaps a thin
968 screwdriver or knife blade to gently pry the locking ears out
969 slightly to extract the connector. We used a locking connector on
970 TeleMetrum to help ensure that the cabling to companion boards
971 used in a rocket don't ever come loose accidentally in flight.
981 <title>AltosUI</title>
983 The AltosUI program provides a graphical user interface for
984 interacting with the Altus Metrum product family, including
985 TeleMetrum and TeleDongle. AltosUI can monitor telemetry data,
986 configure TeleMetrum and TeleDongle devices and many other
987 tasks. The primary interface window provides a selection of
988 buttons, one for each major activity in the system. This manual
989 is split into chapters, each of which documents one of the tasks
990 provided from the top-level toolbar.
993 <title>Packet Command Mode</title>
994 <subtitle>Controlling TeleMetrum Over The Radio Link</subtitle>
996 One of the unique features of the Altus Metrum environment is
997 the ability to create a two way command link between TeleDongle
998 and TeleMetrum using the digital radio transceivers built into
999 each device. This allows you to interact with TeleMetrum from
1000 afar, as if it were directly connected to the computer.
1003 Any operation which can be performed with TeleMetrum
1004 can either be done with TeleMetrum directly connected to
1005 the computer via the USB cable, or through the packet
1006 link. Simply select the appropriate TeleDongle device when
1007 the list of devices is presented and AltosUI will use packet
1011 One oddity in the current interface is how AltosUI selects the
1012 channel for packet mode communications. Instead of providing
1013 an interface to specifically configure the channel, it uses
1014 whatever channel was most recently selected for the target
1015 TeleDongle device in Monitor Flight mode. If you haven't ever
1016 used that mode with the TeleDongle in question, select the
1017 Monitor Flight button from the top level UI, pick the
1018 appropriate TeleDongle device. Once the flight monitoring
1019 window is open, select the desired channel and then close it
1020 down again. All Packet Command Mode operations will now use
1026 Save Flight Data—Recover flight data from the rocket without
1032 Configure TeleMetrum—Reset apogee delays or main deploy
1033 heights to respond to changing launch conditions. You can
1034 also 'reboot' the TeleMetrum device. Use this to remotely
1035 enable the flight computer by turning TeleMetrum on while
1036 horizontal, then once the airframe is oriented for launch,
1037 you can reboot TeleMetrum and have it restart in pad mode
1038 without having to climb the scary ladder.
1043 Fire Igniters—Test your deployment charges without snaking
1044 wires out through holes in the airframe. Simply assembly the
1045 rocket as if for flight with the apogee and main charges
1046 loaded, then remotely command TeleMetrum to fire the
1052 Packet command mode uses the same RF channels as telemetry
1053 mode. Configure the desired TeleDongle channel using the
1054 flight monitor window channel selector and then close that
1055 window before performing the desired operation.
1058 TeleMetrum only enables packet command mode in 'idle' mode, so
1059 make sure you have TeleMetrum lying horizontally when you turn
1060 it on. Otherwise, TeleMetrum will start in 'pad' mode ready for
1061 flight and will not be listening for command packets from TeleDongle.
1064 When packet command mode is enabled, you can monitor the link
1065 by watching the lights on the TeleDongle and TeleMetrum
1066 devices. The red LED will flash each time TeleDongle or
1067 TeleMetrum transmit a packet while the green LED will light up
1068 on TeleDongle while it is waiting to receive a packet from
1073 <title>Monitor Flight</title>
1074 <subtitle>Receive, Record and Display Telemetry Data</subtitle>
1076 Selecting this item brings up a dialog box listing all of the
1077 connected TeleDongle devices. When you choose one of these,
1078 AltosUI will create a window to display telemetry data as
1079 received by the selected TeleDongle device.
1082 All telemetry data received are automatically recorded in
1083 suitable log files. The name of the files includes the current
1084 date and rocket serial and flight numbers.
1087 The radio channel being monitored by the TeleDongle device is
1088 displayed at the top of the window. You can configure the
1089 channel by clicking on the channel box and selecting the desired
1090 channel. AltosUI remembers the last channel selected for each
1091 TeleDongle and selects that automatically the next time you use
1095 Below the TeleDongle channel selector, the window contains a few
1096 significant pieces of information about the TeleMetrum providing
1097 the telemetry data stream:
1101 <para>The TeleMetrum callsign</para>
1104 <para>The TeleMetrum serial number</para>
1107 <para>The flight number. Each TeleMetrum remembers how many
1113 The rocket flight state. Each flight passes through several
1114 states including Pad, Boost, Fast, Coast, Drogue, Main and
1120 The Received Signal Strength Indicator value. This lets
1121 you know how strong a signal TeleDongle is receiving. The
1122 radio inside TeleDongle operates down to about -99dBm;
1123 weaker signals may not be receiveable. The packet link uses
1124 error correction and detection techniques which prevent
1125 incorrect data from being reported.
1130 Finally, the largest portion of the window contains a set of
1131 tabs, each of which contain some information about the rocket.
1132 They're arranged in 'flight order' so that as the flight
1133 progresses, the selected tab automatically switches to display
1134 data relevant to the current state of the flight. You can select
1135 other tabs at any time. The final 'table' tab contains all of
1136 the telemetry data in one place.
1139 <title>Launch Pad</title>
1141 The 'Launch Pad' tab shows information used to decide when the
1142 rocket is ready for flight. The first elements include red/green
1143 indicators, if any of these is red, you'll want to evaluate
1144 whether the rocket is ready to launch:
1148 Battery Voltage. This indicates whether the LiPo battery
1149 powering the TeleMetrum has sufficient charge to last for
1150 the duration of the flight. A value of more than
1151 3.7V is required for a 'GO' status.
1156 Apogee Igniter Voltage. This indicates whether the apogee
1157 igniter has continuity. If the igniter has a low
1158 resistance, then the voltage measured here will be close
1159 to the LiPo battery voltage. A value greater than 3.2V is
1160 required for a 'GO' status.
1165 Main Igniter Voltage. This indicates whether the main
1166 igniter has continuity. If the igniter has a low
1167 resistance, then the voltage measured here will be close
1168 to the LiPo battery voltage. A value greater than 3.2V is
1169 required for a 'GO' status.
1174 GPS Locked. This indicates whether the GPS receiver is
1175 currently able to compute position information. GPS requires
1176 at least 4 satellites to compute an accurate position.
1181 GPS Ready. This indicates whether GPS has reported at least
1182 10 consecutive positions without losing lock. This ensures
1183 that the GPS receiver has reliable reception from the
1189 The LaunchPad tab also shows the computed launch pad position
1190 and altitude, averaging many reported positions to improve the
1191 accuracy of the fix.
1196 <title>Ascent</title>
1198 This tab is shown during Boost, Fast and Coast
1199 phases. The information displayed here helps monitor the
1200 rocket as it heads towards apogee.
1203 The height, speed and acceleration are shown along with the
1204 maxium values for each of them. This allows you to quickly
1205 answer the most commonly asked questions you'll hear during
1209 The current latitude and longitude reported by the GPS are
1210 also shown. Note that under high acceleration, these values
1211 may not get updated as the GPS receiver loses position
1212 fix. Once the rocket starts coasting, the receiver should
1213 start reporting position again.
1216 Finally, the current igniter voltages are reported as in the
1217 Launch Pad tab. This can help diagnose deployment failures
1218 caused by wiring which comes loose under high acceleration.
1222 <title>Descent</title>
1224 Once the rocket has reached apogee and (we hope) activated the
1225 apogee charge, attention switches to tracking the rocket on
1226 the way back to the ground, and for dual-deploy flights,
1227 waiting for the main charge to fire.
1230 To monitor whether the apogee charge operated correctly, the
1231 current descent rate is reported along with the current
1232 height. Good descent rates generally range from 15-30m/s.
1235 To help locate the rocket in the sky, use the elevation and
1236 bearing information to figure out where to look. Elevation is
1237 in degrees above the horizon. Bearing is reported in degrees
1238 relative to true north. Range can help figure out how big the
1239 rocket will appear. Note that all of these values are relative
1240 to the pad location. If the elevation is near 90°, the rocket
1241 is over the pad, not over you.
1244 Finally, the igniter voltages are reported in this tab as
1245 well, both to monitor the main charge as well as to see what
1246 the status of the apogee charge is.
1250 <title>Landed</title>
1252 Once the rocket is on the ground, attention switches to
1253 recovery. While the radio signal is generally lost once the
1254 rocket is on the ground, the last reported GPS position is
1255 generally within a short distance of the actual landing location.
1258 The last reported GPS position is reported both by
1259 latitude and longitude as well as a bearing and distance from
1260 the launch pad. The distance should give you a good idea of
1261 whether you'll want to walk or hitch a ride. Take the reported
1262 latitude and longitude and enter them into your handheld GPS
1263 unit and have that compute a track to the landing location.
1266 Finally, the maximum height, speed and acceleration reported
1267 during the flight are displayed for your admiring observers.
1271 <title>Site Map</title>
1273 When the rocket gets a GPS fix, the Site Map tab will map
1274 the rocket's position to make it easier for you to locate the
1275 rocket, both while it is in the air, and when it has landed. The
1276 rocket's state is indicated by colour: white for pad, red for
1277 boost, pink for fast, yellow for coast, light blue for drogue,
1278 dark blue for main, and black for landed.
1281 The map's scale is approximately 3m (10ft) per pixel. The map
1282 can be dragged using the left mouse button. The map will attempt
1283 to keep the rocket roughly centred while data is being received.
1286 Images are fetched automatically via the Google Maps Static API,
1287 and are cached for reuse. If map images cannot be downloaded,
1288 the rocket's path will be traced on a dark grey background
1294 <title>Save Flight Data</title>
1296 TeleMetrum records flight data to its internal flash memory.
1297 This data is recorded at a much higher rate than the telemetry
1298 system can handle, and is not subject to radio drop-outs. As
1299 such, it provides a more complete and precise record of the
1300 flight. The 'Save Flight Data' button allows you to read the
1301 flash memory and write it to disk.
1304 Clicking on the 'Save Flight Data' button brings up a list of
1305 connected TeleMetrum and TeleDongle devices. If you select a
1306 TeleMetrum device, the flight data will be downloaded from that
1307 device directly. If you select a TeleDongle device, flight data
1308 will be downloaded from a TeleMetrum device connected via the
1309 packet command link to the specified TeleDongle. See the chapter
1310 on Packet Command Mode for more information about this.
1313 After the device has been selected, a dialog showing the
1314 flight data saved in the device will be shown allowing you to
1315 select which flights to download and which to delete. With
1316 version 0.9 or newer firmware, you must erase flights in order
1317 for the space they consume to be reused by another
1318 flight. This prevents you from accidentally losing flight data
1319 if you neglect to download data before flying again. Note that
1320 if there is no more space available in the device, then no
1321 data will be recorded for a flight.
1324 The filename for each flight log is computed automatically
1325 from the recorded flight date, TeleMetrum serial number and
1326 flight number information.
1330 <title>Replay Flight</title>
1332 Select this button and you are prompted to select a flight
1333 record file, either a .telem file recording telemetry data or a
1334 .eeprom file containing flight data saved from the TeleMetrum
1338 Once a flight record is selected, the flight monitor interface
1339 is displayed and the flight is re-enacted in real time. Check
1340 the Monitor Flight chapter above to learn how this window operates.
1344 <title>Graph Data</title>
1346 Select this button and you are prompted to select a flight
1347 record file, either a .telem file recording telemetry data or a
1348 .eeprom file containing flight data saved from the TeleMetrum
1352 Once a flight record is selected, the acceleration (blue),
1353 velocity (green) and altitude (red) of the flight are plotted and
1354 displayed, measured in metric units.
1357 The graph can be zoomed into a particular area by clicking and
1358 dragging down and to the right. Once zoomed, the graph can be
1359 reset by clicking and dragging up and to the left. Holding down
1360 control and clicking and dragging allows the graph to be panned.
1361 The right mouse button causes a popup menu to be displayed, giving
1362 you the option save or print the plot.
1365 Note that telemetry files will generally produce poor graphs
1366 due to the lower sampling rate and missed telemetry packets,
1367 and will also often have significant amounts of data received
1368 while the rocket was waiting on the pad. Use saved flight data
1369 for graphing where possible.
1373 <title>Export Data</title>
1375 This tool takes the raw data files and makes them available for
1376 external analysis. When you select this button, you are prompted to select a flight
1377 data file (either .eeprom or .telem will do, remember that
1378 .eeprom files contain higher resolution and more continuous
1379 data). Next, a second dialog appears which is used to select
1380 where to write the resulting file. It has a selector to choose
1381 between CSV and KML file formats.
1384 <title>Comma Separated Value Format</title>
1386 This is a text file containing the data in a form suitable for
1387 import into a spreadsheet or other external data analysis
1388 tool. The first few lines of the file contain the version and
1389 configuration information from the TeleMetrum device, then
1390 there is a single header line which labels all of the
1391 fields. All of these lines start with a '#' character which
1392 most tools can be configured to skip over.
1395 The remaining lines of the file contain the data, with each
1396 field separated by a comma and at least one space. All of
1397 the sensor values are converted to standard units, with the
1398 barometric data reported in both pressure, altitude and
1399 height above pad units.
1403 <title>Keyhole Markup Language (for Google Earth)</title>
1405 This is the format used by
1406 Googleearth to provide an overlay within that
1407 application. With this, you can use Googleearth to see the
1408 whole flight path in 3D.
1413 <title>Configure TeleMetrum</title>
1415 Select this button and then select either a TeleMetrum or
1416 TeleDongle Device from the list provided. Selecting a TeleDongle
1417 device will use Packet Comamnd Mode to configure remote
1418 TeleMetrum device. Learn how to use this in the Packet Command
1422 The first few lines of the dialog provide information about the
1423 connected TeleMetrum device, including the product name,
1424 software version and hardware serial number. Below that are the
1425 individual configuration entries.
1428 At the bottom of the dialog, there are four buttons:
1433 Save. This writes any changes to the TeleMetrum
1434 configuration parameter block in flash memory. If you don't
1435 press this button, any changes you make will be lost.
1440 Reset. This resets the dialog to the most recently saved values,
1441 erasing any changes you have made.
1446 Reboot. This reboots the TeleMetrum device. Use this to
1447 switch from idle to pad mode by rebooting once the rocket is
1448 oriented for flight.
1453 Close. This closes the dialog. Any unsaved changes will be
1459 The rest of the dialog contains the parameters to be configured.
1462 <title>Main Deploy Altitude</title>
1464 This sets the altitude (above the recorded pad altitude) at
1465 which the 'main' igniter will fire. The drop-down menu shows
1466 some common values, but you can edit the text directly and
1467 choose whatever you like. If the apogee charge fires below
1468 this altitude, then the main charge will fire two seconds
1469 after the apogee charge fires.
1473 <title>Apogee Delay</title>
1475 When flying redundant electronics, it's often important to
1476 ensure that multiple apogee charges don't fire at precisely
1477 the same time as that can overpressurize the apogee deployment
1478 bay and cause a structural failure of the airframe. The Apogee
1479 Delay parameter tells the flight computer to fire the apogee
1480 charge a certain number of seconds after apogee has been
1485 <title>Radio Channel</title>
1487 This configures which of the 10 radio channels to use for both
1488 telemetry and packet command mode. Note that if you set this
1489 value via packet command mode, you will have to reconfigure
1490 the TeleDongle channel before you will be able to use packet
1495 <title>Radio Calibration</title>
1497 The radios in every Altus Metrum device are calibrated at the
1498 factory to ensure that they transmit and receive on the
1499 specified frequency for each channel. You can adjust that
1500 calibration by changing this value. To change the TeleDongle's
1501 calibration, you must reprogram the unit completely.
1505 <title>Callsign</title>
1507 This sets the callsign included in each telemetry packet. Set this
1508 as needed to conform to your local radio regulations.
1512 <title>Maximum Flight Log Size</title>
1514 This sets the space (in kilobytes) allocated for each flight
1515 log. The available space will be divided into chunks of this
1516 size. A smaller value will allow more flights to be stored,
1517 a larger value will record data from longer flights.
1520 During ascent, TeleMetrum records barometer and
1521 accelerometer values 100 times per second, other analog
1522 information (voltages and temperature) 6 times per second
1523 and GPS data once per second. During descent, the non-GPS
1524 data is recorded 1/10th as often. Each barometer +
1525 accelerometer record takes 8 bytes.
1528 The default, 192kB, will store over 200 seconds of data at
1529 the ascent rate, or over 2000 seconds of data at the descent
1530 rate. That's plenty for most flights. This leaves enough
1531 storage for five flights in a 1MB system, or 10 flights in a
1535 The configuration block takes the last available block of
1536 memory, on v1.0 boards that's just 256 bytes. However, the
1537 flash part on the v1.1 boards uses 64kB for each block.
1542 <title>Configure AltosUI</title>
1544 This button presents a dialog so that you can configure the AltosUI global settings.
1547 <title>Voice Settings</title>
1549 AltosUI provides voice annoucements during flight so that you
1550 can keep your eyes on the sky and still get information about
1551 the current flight status. However, sometimes you don't want
1556 <para>Enable—turns all voice announcements on and off</para>
1560 Test Voice—Plays a short message allowing you to verify
1561 that the audio systme is working and the volume settings
1568 <title>Log Directory</title>
1570 AltosUI logs all telemetry data and saves all TeleMetrum flash
1571 data to this directory. This directory is also used as the
1572 staring point when selecting data files for display or export.
1575 Click on the directory name to bring up a directory choosing
1576 dialog, select a new directory and click 'Select Directory' to
1577 change where AltosUI reads and writes data files.
1581 <title>Callsign</title>
1583 This value is used in command packet mode and is transmitted
1584 in each packet sent from TeleDongle and received from
1585 TeleMetrum. It is not used in telemetry mode as that transmits
1586 packets only from TeleMetrum to TeleDongle. Configure this
1587 with the AltosUI operators callsign as needed to comply with
1588 your local radio regulations.
1592 <title>Serial Debug</title>
1594 This causes all communication with a connected device to be
1595 dumped to the console from which AltosUI was started. If
1596 you've started it from an icon or menu entry, the output
1597 will simply be discarded. This mode can be useful to debug
1598 various serial communication issues.
1603 <title>Flash Image</title>
1605 This reprograms any Altus Metrum device by using a TeleMetrum or
1606 TeleDongle as a programming dongle. Please read the directions
1607 for connecting the programming cable in the main TeleMetrum
1608 manual before reading these instructions.
1611 Once you have the programmer and target devices connected,
1612 push the 'Flash Image' button. That will present a dialog box
1613 listing all of the connected devices. Carefully select the
1614 programmer device, not the device to be programmed.
1617 Next, select the image to flash to the device. These are named
1618 with the product name and firmware version. The file selector
1619 will start in the directory containing the firmware included
1620 with the AltosUI package. Navigate to the directory containing
1621 the desired firmware if it isn't there.
1624 Next, a small dialog containing the device serial number and
1625 RF calibration values should appear. If these values are
1626 incorrect (possibly due to a corrupted image in the device),
1627 enter the correct values here.
1630 Finally, a dialog containing a progress bar will follow the
1631 programming process.
1634 When programming is complete, the target device will
1635 reboot. Note that if the target device is connected via USB, you
1636 will have to unplug it and then plug it back in for the USB
1637 connection to reset so that you can communicate with the device
1642 <title>Fire Igniter</title>
1644 This activates the igniter circuits in TeleMetrum to help test
1645 recovery systems deployment. Because this command can operate
1646 over the Packet Command Link, you can prepare the rocket as
1647 for flight and then test the recovery system without needing
1648 to snake wires inside the airframe.
1651 Selecting the 'Fire Igniter' button brings up the usual device
1652 selection dialog. Pick the desired TeleDongle or TeleMetrum
1653 device. This brings up another window which shows the current
1654 continutity test status for both apogee and main charges.
1657 Next, select the desired igniter to fire. This will enable the
1661 Select the 'Arm' button. This enables the 'Fire' button. The
1662 word 'Arm' is replaced by a countdown timer indicating that
1663 you have 10 seconds to press the 'Fire' button or the system
1664 will deactivate, at which point you start over again at
1665 selecting the desired igniter.
1670 <title>Using Altus Metrum Products</title>
1672 <title>Being Legal</title>
1674 First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
1675 other authorization to legally operate the radio transmitters that are part
1680 <title>In the Rocket</title>
1682 In the rocket itself, you just need a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> board and
1683 a LiPo rechargeable battery. An 860mAh battery weighs less than a 9V
1684 alkaline battery, and will run a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> for hours.
1687 By default, we ship TeleMetrum with a simple wire antenna. If your
1688 electronics bay or the airframe it resides within is made of carbon fiber,
1689 which is opaque to RF signals, you may choose to have an SMA connector
1690 installed so that you can run a coaxial cable to an antenna mounted
1691 elsewhere in the rocket.
1695 <title>On the Ground</title>
1697 To receive the data stream from the rocket, you need an antenna and short
1698 feedline connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> units. The
1699 TeleDongle in turn plugs directly into the USB port on a notebook
1700 computer. Because TeleDongle looks like a simple serial port, your computer
1701 does not require special device drivers... just plug it in.
1704 The GUI tool, AltosUI, is written in Java and runs across
1705 Linux, Mac OS and Windows. There's also a suite of C tools
1706 for Linux which can perform most of the same tasks.
1709 After the flight, you can use the RF link to extract the more detailed data
1710 logged in the rocket, or you can use a mini USB cable to plug into the
1711 TeleMetrum board directly. Pulling out the data without having to open up
1712 the rocket is pretty cool! A USB cable is also how you charge the LiPo
1713 battery, so you'll want one of those anyway... the same cable used by lots
1714 of digital cameras and other modern electronic stuff will work fine.
1717 If your rocket lands out of sight, you may enjoy having a hand-held GPS
1718 receiver, so that you can put in a waypoint for the last reported rocket
1719 position before touch-down. This makes looking for your rocket a lot like
1720 Geo-Cacheing... just go to the waypoint and look around starting from there.
1723 You may also enjoy having a ham radio "HT" that covers the 70cm band... you
1724 can use that with your antenna to direction-find the rocket on the ground
1725 the same way you can use a Walston or Beeline tracker. This can be handy
1726 if the rocket is hiding in sage brush or a tree, or if the last GPS position
1727 doesn't get you close enough because the rocket dropped into a canyon, or
1728 the wind is blowing it across a dry lake bed, or something like that... Keith
1729 and Bdale both currently own and use the Yaesu VX-7R at launches.
1732 So, to recap, on the ground the hardware you'll need includes:
1733 <orderedlist inheritnum='inherit' numeration='arabic'>
1735 an antenna and feedline
1744 optionally, a handheld GPS receiver
1747 optionally, an HT or receiver covering 435 Mhz
1752 The best hand-held commercial directional antennas we've found for radio
1753 direction finding rockets are from
1754 <ulink url="http://www.arrowantennas.com/" >
1757 The 440-3 and 440-5 are both good choices for finding a
1758 TeleMetrum-equipped rocket when used with a suitable 70cm HT.
1762 <title>Data Analysis</title>
1764 Our software makes it easy to log the data from each flight, both the
1765 telemetry received over the RF link during the flight itself, and the more
1766 complete data log recorded in the DataFlash memory on the TeleMetrum
1767 board. Once this data is on your computer, our postflight tools make it
1768 easy to quickly get to the numbers everyone wants, like apogee altitude,
1769 max acceleration, and max velocity. You can also generate and view a
1770 standard set of plots showing the altitude, acceleration, and
1771 velocity of the rocket during flight. And you can even export a data file
1772 useable with Google Maps and Google Earth for visualizing the flight path
1773 in two or three dimensions!
1776 Our ultimate goal is to emit a set of files for each flight that can be
1777 published as a web page per flight, or just viewed on your local disk with
1782 <title>Future Plans</title>
1784 In the future, we intend to offer "companion boards" for the rocket that will
1785 plug in to TeleMetrum to collect additional data, provide more pyro channels,
1786 and so forth. A reference design for a companion board will be documented
1787 soon, and will be compatible with open source Arduino programming tools.
1790 We are also working on the design of a hand-held ground terminal that will
1791 allow monitoring the rocket's status, collecting data during flight, and
1792 logging data after flight without the need for a notebook computer on the
1793 flight line. Particularly since it is so difficult to read most notebook
1794 screens in direct sunlight, we think this will be a great thing to have.
1797 Because all of our work is open, both the hardware designs and the software,
1798 if you have some great idea for an addition to the current Altus Metrum family,
1799 feel free to dive in and help! Or let us know what you'd like to see that
1800 we aren't already working on, and maybe we'll get excited about it too...
projects / fw / altos / blob