X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=doc%2Ftelemetrum-doc.xsl;fp=doc%2Ftelemetrum-doc.xsl;h=0000000000000000000000000000000000000000;hp=0c20b2857914892dc76d10b1538dd1cc0b60c270;hb=cb08bc264c71ca972027392b42f347a03df76a43;hpb=554bdd25e132dbaec322bc11f94093d2c2e78751 diff --git a/doc/telemetrum-doc.xsl b/doc/telemetrum-doc.xsl deleted file mode 100644 index 0c20b285..00000000 --- a/doc/telemetrum-doc.xsl +++ /dev/null @@ -1,1735 +0,0 @@ - - - - The Altus Metrum System - Owner's Manual for TeleMetrum and TeleDongle Devices - - - Bdale - Garbee - - - Keith - Packard - - - Bob - Finch - - - Anthony - Towns - - - 2010 - Bdale Garbee and Keith Packard - - - - This document is released under the terms of the - - Creative Commons ShareAlike 3.0 - - license. - - - - - 0.8 - 24 November 2010 - Updated for software version 0.8 - - - - - - Thanks to Bob Finch, W9YA, NAR 12965, TRA 12350 for writing "The - Mere-Mortals Quick Start/Usage Guide to the Altus Metrum Starter - Kit" which has turned into the Getting Started chapter in this - book. Bob was one of our first customers for a production - TeleMetrum, and the enthusiasm that led to his contribution of - this section is immensely gratifying and highy appreciated! - - - And thanks to Anthony (AJ) Towns for contributing the - AltosUI graphing and site map code and documentation. Free - software means that our customers and friends can become our - collaborators, and we certainly appreciate this level of - contribution. - - - Have fun using these products, and we hope to meet all of you - out on the rocket flight line somewhere. - -Bdale Garbee, KB0G -NAR #87103, TRA #12201 - -Keith Packard, KD7SQG -NAR #88757, TRA #12200 - - - - - Introduction and Overview - - Welcome to the Altus Metrum community! Our circuits and software reflect - our passion for both hobby rocketry and Free Software. We hope their - capabilities and performance will delight you in every way, but by - releasing all of our hardware and software designs under open licenses, - we also hope to empower you to take as active a role in our collective - future as you wish! - - - The focal point of our community is TeleMetrum, a dual deploy altimeter - with fully integrated GPS and radio telemetry as standard features, and - a "companion interface" that will support optional capabilities in the - future. - - - Complementing TeleMetrum is TeleDongle, a USB to RF interface for - communicating with TeleMetrum. Combined with your choice of antenna and - notebook computer, TeleDongle and our associated user interface software - form a complete ground station capable of logging and displaying in-flight - telemetry, aiding rocket recovery, then processing and archiving flight - data for analysis and review. - - - More products will be added to the Altus Metrum family over time, and - we currently envision that this will be a single, comprehensive manual - for the entire product family. - - - - Getting Started - - The first thing to do after you check the inventory of parts in your - "starter kit" is to charge the battery by plugging it into the - corresponding socket of the TeleMetrum and then using the USB A to - mini B - cable to plug the Telemetrum into your computer's USB socket. The - TeleMetrum circuitry will charge the battery whenever it is plugged - in, because the TeleMetrum's on-off switch does NOT control the - charging circuitry. When the GPS chip is initially searching for - satellites, TeleMetrum will consume more current than it can pull - from the usb port, so the battery must be attached in order to get - satellite lock. Once GPS is locked, the current consumption goes back - down enough to enable charging while - running. So it's a good idea to fully charge the battery as your - first item of business so there is no issue getting and maintaining - satellite lock. The yellow charge indicator led will go out when the - battery is nearly full and the charger goes to trickle charge. It - can take several hours to fully recharge a deeply discharged battery. - - - The other active device in the starter kit is the TeleDongle USB to - RF interface. If you plug it in to your Mac or Linux computer it should - "just work", showing up as a serial port device. Windows systems need - driver information that is part of the AltOS download to know that the - existing USB modem driver will work. If you are using Linux and are - having problems, try moving to a fresher kernel (2.6.33 or newer), as - the USB serial driver had ugly bugs in some earlier versions. - - - Next you should obtain and install the AltOS utilities. These include - the AltosUI ground station program, current firmware images for - TeleMetrum and TeleDongle, and a number of standalone utilities that - are rarely needed. Pre-built binary packages are available for Debian - Linux, Microsoft Windows, and recent MacOSX versions. Full sourcecode - and build instructions for some other Linux variants are also available. - The latest version may always be downloaded from - . - - - Both Telemetrum and TeleDongle can be directly communicated - with using USB ports. The first thing you should try after getting - both units plugged into to your computer's usb port(s) is to run - 'ao-list' from a terminal-window to see what port-device-name each - device has been assigned by the operating system. - You will need this information to access the devices via their - respective on-board firmware and data using other command line - programs in the AltOS software suite. - - - To access the device's firmware for configuration you need a terminal - program such as you would use to talk to a modem. The software - authors prefer using the program 'cu' which comes from the UUCP package - on most Unix-like systems such as Linux. An example command line for - cu might be 'cu -l /dev/ttyACM0', substituting the correct number - indicated from running the - ao-list program. Another reasonable terminal program for Linux is - 'cutecom'. The default 'escape' - character used by CU (i.e. the character you use to - issue commands to cu itself instead of sending the command as input - to the connected device) is a '~'. You will need this for use in - only two different ways during normal operations. First is to exit - the program by sending a '~.' which is called a 'escape-disconnect' - and allows you to close-out from 'cu'. The - second use will be outlined later. - - - Both TeleMetrum and TeleDongle share the concept of a two level - command set in their firmware. - The first layer has several single letter commands. Once - you are using 'cu' (or 'cutecom') sending (typing) a '?' - returns a full list of these - commands. The second level are configuration sub-commands accessed - using the 'c' command, for - instance typing 'c?' will give you this second level of commands - (all of which require the - letter 'c' to access). Please note that most configuration options - are stored only in DataFlash memory, and only TeleMetrum has this - memory to save the various values entered like the channel number - and your callsign when powered off. TeleDongle requires that you - set these each time you plug it in, which ao-view can help with. - - - Try setting these config ('c' or second level menu) values. A good - place to start is by setting your call sign. By default, the boards - use 'N0CALL' which is cute, but not exactly legal! - Spend a few minutes getting comfortable with the units, their - firmware, and 'cu' (or possibly 'cutecom'). - For instance, try to send - (type) a 'c r 2' and verify the channel change by sending a 'c s'. - Verify you can connect and disconnect from the units while in your - terminal program by sending the escape-disconnect mentioned above. - - - Note that the 'reboot' command, which is very useful on TeleMetrum, - will likely just cause problems with the dongle. The *correct* way - to reset the dongle is just to unplug and re-plug it. - - - A fun thing to do at the launch site and something you can do while - learning how to use these units is to play with the rf-link access - of the TeleMetrum from the TeleDongle. Be aware that you *must* create - some physical separation between the devices, otherwise the link will - not function due to signal overload in the receivers in each device. - - - Now might be a good time to take a break and read the rest of this - manual, particularly about the two "modes" that the TeleMetrum - can be placed in and how the position of the TeleMetrum when booting - up will determine whether the unit is in "pad" or "idle" mode. - - - You can access a TeleMetrum in idle mode from the Teledongle's USB - connection using the rf link - by issuing a 'p' command to the TeleDongle. Practice connecting and - disconnecting ('~~' while using 'cu') from the TeleMetrum. If - you cannot escape out of the "p" command, (by using a '~~' when in - CU) then it is likely that your kernel has issues. Try a newer version. - - - Using this rf link allows you to configure the TeleMetrum, test - fire e-matches and igniters from the flight line, check pyro-match - continuity and so forth. You can leave the unit turned on while it - is in 'idle mode' and then place the - rocket vertically on the launch pad, walk away and then issue a - reboot command. The TeleMetrum will reboot and start sending data - having changed to the "pad" mode. If the TeleDongle is not receiving - this data, you can disconnect 'cu' from the Teledongle using the - procedures mentioned above and THEN connect to the TeleDongle from - inside 'ao-view'. If this doesn't work, disconnect from the - TeleDongle, unplug it, and try again after plugging it back in. - - - Eventually the GPS will find enough satellites, lock in on them, - and 'ao-view' will both auditorially announce and visually indicate - that GPS is ready. - Now you can launch knowing that you have a good data path and - good satellite lock for flight data and recovery. Remember - you MUST tell ao-view to connect to the TeleDongle explicitly in - order for ao-view to be able to receive data. - - - Both RDF (radio direction finding) tones from the TeleMetrum and - GPS trekking data are available and together are very useful in - locating the rocket once it has landed. (The last good GPS data - received before touch-down will be on the data screen of 'ao-view'.) - - - Once you have recovered the rocket you can download the eeprom - contents using either 'ao-dumplog' (or possibly 'ao-eeprom'), over - either a USB cable or over the radio link using TeleDongle. - And by following the man page for 'ao-postflight' you can create - various data output reports, graphs, and even kml data to see the - flight trajectory in google-earth. (Moving the viewing angle making - sure to connect the yellow lines while in google-earth is the proper - technique.) - - - As for ao-view.... some things are in the menu but don't do anything - very useful. The developers have stopped working on ao-view to focus - on a new, cross-platform ground station program. So ao-view may or - may not be updated in the future. Mostly you just use - the Log and Device menus. It has a wonderful display of the incoming - flight data and I am sure you will enjoy what it has to say to you - once you enable the voice output! - -
- FAQ - - The altimeter (TeleMetrum) seems to shut off when disconnected from the - computer. Make sure the battery is adequately charged. Remember the - unit will pull more power than the USB port can deliver before the - GPS enters "locked" mode. The battery charges best when TeleMetrum - is turned off. - - - It's impossible to stop the TeleDongle when it's in "p" mode, I have - to unplug the USB cable? Make sure you have tried to "escape out" of - this mode. If this doesn't work the reboot procedure for the - TeleDongle *is* to simply unplug it. 'cu' however will retain it's - outgoing buffer IF your "escape out" ('~~') does not work. - At this point using either 'ao-view' (or possibly - 'cutemon') instead of 'cu' will 'clear' the issue and allow renewed - communication. - - - The amber LED (on the TeleMetrum/altimeter) lights up when both - battery and USB are connected. Does this mean it's charging? - Yes, the yellow LED indicates the charging at the 'regular' rate. - If the led is out but the unit is still plugged into a USB port, - then the battery is being charged at a 'trickle' rate. - - - There are no "dit-dah-dah-dit" sound like the manual mentions? - That's the "pad" mode. Weak batteries might be the problem. - It is also possible that the unit is horizontal and the output - is instead a "dit-dit" meaning 'idle'. - - - It's unclear how to use 'ao-view' and other programs when 'cu' - is running. You cannot have more than one program connected to - the TeleDongle at one time without apparent data loss as the - incoming data will not make it to both programs intact. - Disconnect whatever programs aren't currently being used. - - - How do I save flight data? - Live telemetry is written to file(s) whenever 'ao-view' is connected - to the TeleDongle. The file area defaults to ~/altos - but is easily changed using the menus in 'ao-view'. The files that - are written end in '.telem'. The after-flight - data-dumped files will end in .eeprom and represent continuous data - unlike the rf-linked .telem files that are subject to the - turnarounds/data-packaging time slots in the half-duplex rf data path. - See the above instructions on what and how to save the eeprom stored - data after physically retrieving your TeleMetrum. Make sure to save - the on-board data after each flight, as the current firmware will - over-write any previous flight data during a new flight. - -
- - - Specifications - - - - Recording altimeter for model rocketry. - - - - - Supports dual deployment (can fire 2 ejection charges). - - - - - 70cm ham-band transceiver for telemetry downlink. - - - - - Barometric pressure sensor good to 45k feet MSL. - - - - - 1-axis high-g accelerometer for motor characterization, capable of - +/- 50g using default part. - - - - - On-board, integrated GPS receiver with 5hz update rate capability. - - - - - On-board 1 megabyte non-volatile memory for flight data storage. - - - - - USB interface for battery charging, configuration, and data recovery. - - - - - Fully integrated support for LiPo rechargeable batteries. - - - - - Uses LiPo to fire e-matches, support for optional separate pyro - battery if needed. - - - - - 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube. - - - - - - Handling Precautions - - TeleMetrum is a sophisticated electronic device. When handled gently and - properly installed in an airframe, it will deliver impressive results. - However, like all electronic devices, there are some precautions you - must take. - - - The Lithium Polymer rechargeable batteries used with TeleMetrum have an - extraordinary power density. This is great because we can fly with - much less battery mass than if we used alkaline batteries or previous - generation rechargeable batteries... but if they are punctured - or their leads are allowed to short, they can and will release their - energy very rapidly! - Thus we recommend that you take some care when handling our batteries - and consider giving them some extra protection in your airframe. We - often wrap them in suitable scraps of closed-cell packing foam before - strapping them down, for example. - - - The TeleMetrum barometric sensor is sensitive to sunlight. In normal - mounting situations, it and all of the other surface mount components - are "down" towards whatever the underlying mounting surface is, so - this is not normally a problem. Please consider this, though, when - designing an installation, for example, in a 29mm airframe with a - see-through plastic payload bay. - - - The TeleMetrum barometric sensor sampling port must be able to - "breathe", - both by not being covered by foam or tape or other materials that might - directly block the hole on the top of the sensor, but also by having a - suitable static vent to outside air. - - - As with all other rocketry electronics, TeleMetrum must be protected - from exposure to corrosive motor exhaust and ejection charge gasses. - - - - Hardware Overview - - TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to - fit inside coupler for 29mm airframe tubing, but using it in a tube that - small in diameter may require some creativity in mounting and wiring - to succeed! The default 1/4 - wave UHF wire antenna attached to the center of the nose-cone end of - the board is about 7 inches long, and wiring for a power switch and - the e-matches for apogee and main ejection charges depart from the - fin can end of the board. Given all this, an ideal "simple" avionics - bay for TeleMetrum should have at least 10 inches of interior length. - - - A typical TeleMetrum installation using the on-board GPS antenna and - default wire UHF antenna involves attaching only a suitable - Lithium Polymer battery, a single pole switch for power on/off, and - two pairs of wires connecting e-matches for the apogee and main ejection - charges. - - - By default, we use the unregulated output of the LiPo battery directly - to fire ejection charges. This works marvelously with standard - low-current e-matches like the J-Tek from MJG Technologies, and with - Quest Q2G2 igniters. However, if you - want or need to use a separate pyro battery, you can do so by adding - a second 2mm connector to position B2 on the board and cutting the - thick pcb trace connecting the LiPo battery to the pyro circuit between - the two silk screen marks on the surface mount side of the board shown - here [insert photo] - - - We offer two choices of pyro and power switch connector, or you can - choose neither and solder wires directly to the board. All three choices - are reasonable depending on the constraints of your airframe. Our - favorite option when there is sufficient room above the board is to use - the Tyco pin header with polarization and locking. If you choose this - option, you crimp individual wires for the power switch and e-matches - into a mating connector, and installing and removing the TeleMetrum - board from an airframe is as easy as plugging or unplugging two - connectors. If the airframe will not support this much height or if - you want to be able to directly attach e-match leads to the board, we - offer a screw terminal block. This is very similar to what most other - altimeter vendors provide and so may be the most familiar option. - You'll need a very small straight blade screwdriver to connect - and disconnect the board in this case, such as you might find in a - jeweler's screwdriver set. Finally, you can forego both options and - solder wires directly to the board, which may be the best choice for - minimum diameter and/or minimum mass designs. - - - For most airframes, the integrated GPS antenna and wire UHF antenna are - a great combination. However, if you are installing in a carbon-fiber - electronics bay which is opaque to RF signals, you may need to use - off-board external antennas instead. In this case, you can order - TeleMetrum with an SMA connector for the UHF antenna connection, and - you can unplug the integrated GPS antenna and select an appropriate - off-board GPS antenna with cable terminating in a U.FL connector. - - - - System Operation -
- Firmware Modes - - The AltOS firmware build for TeleMetrum has two fundamental modes, - "idle" and "flight". Which of these modes the firmware operates in - is determined by the orientation of the rocket (well, actually the - board, of course...) at the time power is switched on. If the rocket - is "nose up", then TeleMetrum assumes it's on a rail or rod being - prepared for launch, so the firmware chooses flight mode. However, - if the rocket is more or less horizontal, the firmware instead enters - idle mode. - - - At power on, you will hear three beeps - ("S" in Morse code for startup) and then a pause while - TeleMetrum completes initialization and self tests, and decides which - mode to enter next. - - - In flight or "pad" mode, TeleMetrum turns on the GPS system, - engages the flight - state machine, goes into transmit-only mode on the RF link sending - telemetry, and waits for launch to be detected. Flight mode is - indicated by an audible "di-dah-dah-dit" ("P" for pad) on the - beeper, followed by - beeps indicating the state of the pyrotechnic igniter continuity. - One beep indicates apogee continuity, two beeps indicate - main continuity, three beeps indicate both apogee and main continuity, - and one longer "brap" sound indicates no continuity. For a dual - deploy flight, make sure you're getting three beeps before launching! - For apogee-only or motor eject flights, do what makes sense. - - - In idle mode, you will hear an audible "di-dit" ("I" for idle), and - the normal flight state machine is disengaged, thus - no ejection charges will fire. TeleMetrum also listens on the RF - link when in idle mode for packet mode requests sent from TeleDongle. - Commands can be issued to a TeleMetrum in idle mode over either - USB or the RF link equivalently. - Idle mode is useful for configuring TeleMetrum, for extracting data - from the on-board storage chip after flight, and for ground testing - pyro charges. - - - One "neat trick" of particular value when TeleMetrum is used with very - large airframes, is that you can power the board up while the rocket - is horizontal, such that it comes up in idle mode. Then you can - raise the airframe to launch position, use a TeleDongle to open - a packet connection, and issue a 'reset' command which will cause - TeleMetrum to reboot, realize it's now nose-up, and thus choose - flight mode. This is much safer than standing on the top step of a - rickety step-ladder or hanging off the side of a launch tower with - a screw-driver trying to turn on your avionics before installing - igniters! - -
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- GPS - - TeleMetrum includes a complete GPS receiver. See a later section for - a brief explanation of how GPS works that will help you understand - the information in the telemetry stream. The bottom line is that - the TeleMetrum GPS receiver needs to lock onto at least four - satellites to obtain a solid 3 dimensional position fix and know - what time it is! - - - TeleMetrum provides backup power to the GPS chip any time a LiPo - battery is connected. This allows the receiver to "warm start" on - the launch rail much faster than if every power-on were a "cold start" - for the GPS receiver. In typical operations, powering up TeleMetrum - on the flight line in idle mode while performing final airframe - preparation will be sufficient to allow the GPS receiver to cold - start and acquire lock. Then the board can be powered down during - RSO review and installation on a launch rod or rail. When the board - is turned back on, the GPS system should lock very quickly, typically - long before igniter installation and return to the flight line are - complete. - -
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- Ground Testing - - An important aspect of preparing a rocket using electronic deployment - for flight is ground testing the recovery system. Thanks - to the bi-directional RF link central to the Altus Metrum system, - this can be accomplished in a TeleMetrum-equipped rocket without as - much work as you may be accustomed to with other systems. It can - even be fun! - - - Just prep the rocket for flight, then power up TeleMetrum while the - airframe is horizontal. This will cause the firmware to go into - "idle" mode, in which the normal flight state machine is disabled and - charges will not fire without manual command. Then, establish an - RF packet connection from a TeleDongle-equipped computer using the - P command from a safe distance. You can now command TeleMetrum to - fire the apogee or main charges to complete your testing. - - - In order to reduce the chance of accidental firing of pyrotechnic - charges, the command to fire a charge is intentionally somewhat - difficult to type, and the built-in help is slightly cryptic to - prevent accidental echoing of characters from the help text back at - the board from firing a charge. The command to fire the apogee - drogue charge is 'i DoIt drogue' and the command to fire the main - charge is 'i DoIt main'. - -
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- Radio Link - - The chip our boards are based on incorporates an RF transceiver, but - it's not a full duplex system... each end can only be transmitting or - receiving at any given moment. So we had to decide how to manage the - link. - - - By design, TeleMetrum firmware listens for an RF connection when - it's in "idle mode" (turned on while the rocket is horizontal), which - allows us to use the RF link to configure the rocket, do things like - ejection tests, and extract data after a flight without having to - crack open the airframe. However, when the board is in "flight - mode" (turned on when the rocket is vertical) the TeleMetrum only - transmits and doesn't listen at all. That's because we want to put - ultimate priority on event detection and getting telemetry out of - the rocket and out over - the RF link in case the rocket crashes and we aren't able to extract - data later... - - - We don't use a 'normal packet radio' mode because they're just too - inefficient. The GFSK modulation we use is just FSK with the - baseband pulses passed through a - Gaussian filter before they go into the modulator to limit the - transmitted bandwidth. When combined with the hardware forward error - correction support in the cc1111 chip, this allows us to have a very - robust 38.4 kilobit data link with only 10 milliwatts of transmit power, - a whip antenna in the rocket, and a hand-held Yagi on the ground. We've - had flights to above 21k feet AGL with good reception, and calculations - suggest we should be good to well over 40k feet AGL with a 5-element yagi on - the ground. We hope to fly boards to higher altitudes soon, and would - of course appreciate customer feedback on performance in higher - altitude flights! - -
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- Configurable Parameters - - Configuring a TeleMetrum board for flight is very simple. Because we - have both acceleration and pressure sensors, there is no need to set - a "mach delay", for example. The few configurable parameters can all - be set using a simple terminal program over the USB port or RF link - via TeleDongle. - -
- Radio Channel - - Our firmware supports 10 channels. The default channel 0 corresponds - to a center frequency of 434.550 Mhz, and channels are spaced every - 100 khz. Thus, channel 1 is 434.650 Mhz, and channel 9 is 435.550 Mhz. - At any given launch, we highly recommend coordinating who will use - each channel and when to avoid interference. And of course, both - TeleMetrum and TeleDongle must be configured to the same channel to - successfully communicate with each other. - - - To set the radio channel, use the 'c r' command, like 'c r 3' to set - channel 3. - As with all 'c' sub-commands, follow this with a 'c w' to write the - change to the parameter block in the on-board DataFlash chip on - your TeleMetrum board if you want the change to stay in place across reboots. - -
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- Apogee Delay - - Apogee delay is the number of seconds after TeleMetrum detects flight - apogee that the drogue charge should be fired. In most cases, this - should be left at the default of 0. However, if you are flying - redundant electronics such as for an L3 certification, you may wish - to set one of your altimeters to a positive delay so that both - primary and backup pyrotechnic charges do not fire simultaneously. - - - To set the apogee delay, use the 'c d' command. - As with all 'c' sub-commands, follow this with a 'c w' to write the - change to the parameter block in the on-board DataFlash chip. - - - Please note that the TeleMetrum apogee detection algorithm always - fires a fraction of a second *after* apogee. If you are also flying - an altimeter like the PerfectFlite MAWD, which only supports selecting - 0 or 1 seconds of apogee delay, you may wish to set the MAWD to 0 - seconds delay and set the TeleMetrum to fire your backup 2 or 3 - seconds later to avoid any chance of both charges firing - simultaneously. We've flown several airframes this way quite happily, - including Keith's successful L3 cert. - -
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- Main Deployment Altitude - - By default, TeleMetrum will fire the main deployment charge at an - elevation of 250 meters (about 820 feet) above ground. We think this - is a good elevation for most airframes, but feel free to change this - to suit. In particular, if you are flying two altimeters, you may - wish to set the - deployment elevation for the backup altimeter to be something lower - than the primary so that both pyrotechnic charges don't fire - simultaneously. - - - To set the main deployment altitude, use the 'c m' command. - As with all 'c' sub-commands, follow this with a 'c w' to write the - change to the parameter block in the on-board DataFlash chip. - -
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- Calibration - - There are only two calibrations required for a TeleMetrum board, and - only one for TeleDongle. - -
- Radio Frequency - - The radio frequency is synthesized from a clock based on the 48 Mhz - crystal on the board. The actual frequency of this oscillator must be - measured to generate a calibration constant. While our GFSK modulation - bandwidth is wide enough to allow boards to communicate even when - their oscillators are not on exactly the same frequency, performance - is best when they are closely matched. - Radio frequency calibration requires a calibrated frequency counter. - Fortunately, once set, the variation in frequency due to aging and - temperature changes is small enough that re-calibration by customers - should generally not be required. - - - To calibrate the radio frequency, connect the UHF antenna port to a - frequency counter, set the board to channel 0, and use the 'C' - command to generate a CW carrier. Wait for the transmitter temperature - to stabilize and the frequency to settle down. - Then, divide 434.550 Mhz by the - measured frequency and multiply by the current radio cal value show - in the 'c s' command. For an unprogrammed board, the default value - is 1186611. Take the resulting integer and program it using the 'c f' - command. Testing with the 'C' command again should show a carrier - within a few tens of Hertz of the intended frequency. - As with all 'c' sub-commands, follow this with a 'c w' to write the - change to the parameter block in the on-board DataFlash chip. - -
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- Accelerometer - - The accelerometer we use has its own 5 volt power supply and - the output must be passed through a resistive voltage divider to match - the input of our 3.3 volt ADC. This means that unlike the barometric - sensor, the output of the acceleration sensor is not ratiometric to - the ADC converter, and calibration is required. We also support the - use of any of several accelerometers from a Freescale family that - includes at least +/- 40g, 50g, 100g, and 200g parts. Using gravity, - a simple 2-point calibration yields acceptable results capturing both - the different sensitivities and ranges of the different accelerometer - parts and any variation in power supply voltages or resistor values - in the divider network. - - - To calibrate the acceleration sensor, use the 'c a 0' command. You - will be prompted to orient the board vertically with the UHF antenna - up and press a key, then to orient the board vertically with the - UHF antenna down and press a key. - As with all 'c' sub-commands, follow this with a 'c w' to write the - change to the parameter block in the on-board DataFlash chip. - - - The +1g and -1g calibration points are included in each telemetry - frame and are part of the header extracted by ao-dumplog after flight. - Note that we always store and return raw ADC samples for each - sensor... nothing is permanently "lost" or "damaged" if the - calibration is poor. - - - In the unlikely event an accel cal that goes badly, it is possible - that TeleMetrum may always come up in 'pad mode' and as such not be - listening to either the USB or radio interfaces. If that happens, - there is a special hook in the firmware to force the board back - in to 'idle mode' so you can re-do the cal. To use this hook, you - just need to ground the SPI clock pin at power-on. This pin is - available as pin 2 on the 8-pin companion connector, and pin 1 is - ground. So either carefully install a fine-gauge wire jumper - between the two pins closest to the index hole end of the 8-pin - connector, or plug in the programming cable to the 8-pin connector - and use a small screwdriver or similar to short the two pins closest - to the index post on the 4-pin end of the programming cable, and - power up the board. It should come up in 'idle mode' (two beeps). - -
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- Updating Device Firmware - - The big conceptual thing to realize is that you have to use a - TeleDongle as a programmer to update a TeleMetrum, and vice versa. - Due to limited memory resources in the cc1111, we don't support - programming either unit directly over USB. - - - You may wish to begin by ensuring you have current firmware images. - These are distributed as part of the AltOS software bundle that - also includes the AltosUI ground station program. Newer ground - station versions typically work fine with older firmware versions, - so you don't need to update your devices just to try out new - software features. You can always download the most recent - version from . - - - We recommend updating TeleMetrum first, before updating TeleDongle. - -
- Updating TeleMetrum Firmware - - - Find the 'programming cable' that you got as part of the starter - kit, that has a red 8-pin MicroMaTch connector on one end and a - red 4-pin MicroMaTch connector on the other end. - - - Take the 2 screws out of the TeleDongle case to get access - to the circuit board. - - - Plug the 8-pin end of the programming cable to the - matching connector on the TeleDongle, and the 4-pin end to the - matching connector on the TeleMetrum. - Note that each MicroMaTch connector has an alignment pin that - goes through a hole in the PC board when you have the cable - oriented correctly. - - - Attach a battery to the TeleMetrum board. - - - Plug the TeleDongle into your computer's USB port, and power - up the TeleMetrum. - - - Run AltosUI, and select 'Flash Image' from the File menu. - - - Pick the TeleDongle device from the list, identifying it as the - programming device. - - - Select the image you want put on the TeleMetrum, which should have a - name in the form telemetrum-v1.0-0.7.1.ihx. It should be visible - in the default directory, if not you may have to poke around - your system to find it. - - - Make sure the configuration parameters are reasonable - looking. If the serial number and/or RF configuration - values aren't right, you'll need to change them. - - - Hit the 'OK' button and the software should proceed to flash - the TeleMetrum with new firmware, showing a progress bar. - - - Confirm that the TeleMetrum board seems to have updated ok, which you - can do by plugging in to it over USB and using a terminal program - to connect to the board and issue the 'v' command to check - the version, etc. - - - If something goes wrong, give it another try. - - -
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- Updating TeleDongle Firmware - - Updating TeleDongle's firmware is just like updating TeleMetrum - firmware, but you switch which board is the programmer and which - is the programming target. - - - - Find the 'programming cable' that you got as part of the starter - kit, that has a red 8-pin MicroMaTch connector on one end and a - red 4-pin MicroMaTch connector on the other end. - - - Find the USB cable that you got as part of the starter kit, and - plug the "mini" end in to the mating connector on TeleMetrum. - - - Take the 2 screws out of the TeleDongle case to get access - to the circuit board. - - - Plug the 8-pin end of the programming cable to the (latching) - matching connector on the TeleMetrum, and the 4-pin end to the - matching connector on the TeleDongle. - Note that each MicroMaTch connector has an alignment pin that - goes through a hole in the PC board when you have the cable - oriented correctly. - - - Attach a battery to the TeleMetrum board. - - - Plug both TeleMetrum and TeleDongle into your computer's USB - ports, and power up the TeleMetrum. - - - Run AltosUI, and select 'Flash Image' from the File menu. - - - Pick the TeleMetrum device from the list, identifying it as the - programming device. - - - Select the image you want put on the TeleDongle, which should have a - name in the form teledongle-v0.2-0.7.1.ihx. It should be visible - in the default directory, if not you may have to poke around - your system to find it. - - - Make sure the configuration parameters are reasonable - looking. If the serial number and/or RF configuration - values aren't right, you'll need to change them. The TeleDongle - serial number is on the "bottom" of the circuit board, and can - usually be read through the translucent blue plastic case without - needing to remove the board from the case. - - - Hit the 'OK' button and the software should proceed to flash - the TeleDongle with new firmware, showing a progress bar. - - - Confirm that the TeleDongle board seems to have updated ok, which you - can do by plugging in to it over USB and using a terminal program - to connect to the board and issue the 'v' command to check - the version, etc. Once you're happy, remove the programming cable - and put the cover back on the TeleDongle. - - - If something goes wrong, give it another try. - - - - Be careful removing the programming cable from the locking 8-pin - connector on TeleMetrum. You'll need a fingernail or perhaps a thin - screwdriver or knife blade to gently pry the locking ears out - slightly to extract the connector. We used a locking connector on - TeleMetrum to help ensure that the cabling to companion boards - used in a rocket don't ever come loose accidentally in flight. - -
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- - - - - - - AltosUI - - The AltosUI program provides a graphical user interface for - interacting with the Altus Metrum product family, including - TeleMetrum and TeleDongle. AltosUI can monitor telemetry data, - configure TeleMetrum and TeleDongle devices and many other - tasks. The primary interface window provides a selection of - buttons, one for each major activity in the system. This manual - is split into chapters, each of which documents one of the tasks - provided from the top-level toolbar. - -
- Packet Command Mode - Controlling TeleMetrum Over The Radio Link - - One of the unique features of the Altos Metrum environment is - the ability to create a two way command link between TeleDongle - and TeleMetrum using the digital radio transceivers built into - each device. This allows you to interact with TeleMetrum from - afar, as if it were directly connected to the computer. - - - Any operation which can be performed with TeleMetrum - can either be done with TeleMetrum directly connected to - the computer via the USB cable, or through the packet - link. Simply select the appropriate TeleDongle device when - the list of devices is presented and AltosUI will use packet - command mode. - - - One oddity in the current interface is how AltosUI selects the - channel for packet mode communications. Instead of providing - an interface to specifically configure the channel, it uses - whatever channel was most recently selected for the target - TeleDongle device in Monitor Flight mode. If you haven't ever - used that mode with the TeleDongle in question, select the - Monitor Flight button from the top level UI, pick the - appropriate TeleDongle device. Once the flight monitoring - window is open, select the desired channel and then close it - down again. All Packet Command Mode operations will now use - that channel. - - - - - Save Flight Data—Recover flight data from the rocket without - opening it up. - - - - - Configure TeleMetrum—Reset apogee delays or main deploy - heights to respond to changing launch conditions. You can - also 'reboot' the TeleMetrum device. Use this to remotely - enable the flight computer by turning TeleMetrum on while - horizontal, then once the airframe is oriented for launch, - you can reboot TeleMetrum and have it restart in pad mode - without having to climb the scary ladder. - - - - - Fire Igniters—Test your deployment charges without snaking - wires out through holes in the airframe. Simply assembly the - rocket as if for flight with the apogee and main charges - loaded, then remotely command TeleMetrum to fire the - igniters. - - - - - Packet command mode uses the same RF channels as telemetry - mode. Configure the desired TeleDongle channel using the - flight monitor window channel selector and then close that - window before performing the desired operation. - - - TeleMetrum only enables packet command mode in 'idle' mode, so - make sure you have TeleMetrum lying horizontally when you turn - it on. Otherwise, TeleMetrum will start in 'pad' mode ready for - flight and will not be listening for command packets from TeleDongle. - - - When packet command mode is enabled, you can monitor the link - by watching the lights on the TeleDongle and TeleMetrum - devices. The red LED will flash each time TeleDongle or - TeleMetrum transmit a packet while the green LED will light up - on TeleDongle while it is waiting to receive a packet from - TeleMetrum. - -
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- Monitor Flight - Receive, Record and Display Telemetry Data - - Selecting this item brings up a dialog box listing all of the - connected TeleDongle devices. When you choose one of these, - AltosUI will create a window to display telemetry data as - received by the selected TeleDongle device. - - - All telemetry data received are automatically recorded in - suitable log files. The name of the files includes the current - date and rocket serial and flight numbers. - - - The radio channel being monitored by the TeleDongle device is - displayed at the top of the window. You can configure the - channel by clicking on the channel box and selecting the desired - channel. AltosUI remembers the last channel selected for each - TeleDongle and selects that automatically the next time you use - that device. - - - Below the TeleDongle channel selector, the window contains a few - significant pieces of information about the TeleMetrum providing - the telemetry data stream: - - - - The TeleMetrum callsign - - - The TeleMetrum serial number - - - The flight number. Each TeleMetrum remembers how many - times it has flown. - - - - - The rocket flight state. Each flight passes through several - states including Pad, Boost, Fast, Coast, Drogue, Main and - Landed. - - - - - The Received Signal Strength Indicator value. This lets - you know how strong a signal TeleDongle is receiving. The - radio inside TeleDongle operates down to about -99dBm; - weaker signals may not be receiveable. The packet link uses - error correction and detection techniques which prevent - incorrect data from being reported. - - - - - Finally, the largest portion of the window contains a set of - tabs, each of which contain some information about the rocket. - They're arranged in 'flight order' so that as the flight - progresses, the selected tab automatically switches to display - data relevant to the current state of the flight. You can select - other tabs at any time. The final 'table' tab contains all of - the telemetry data in one place. - -
- Launch Pad - - The 'Launch Pad' tab shows information used to decide when the - rocket is ready for flight. The first elements include red/green - indicators, if any of these is red, you'll want to evaluate - whether the rocket is ready to launch: - - - - Battery Voltage. This indicates whether the LiPo battery - powering the TeleMetrum has sufficient charge to last for - the duration of the flight. A value of more than - 3.7V is required for a 'GO' status. - - - - - Apogee Igniter Voltage. This indicates whether the apogee - igniter has continuity. If the igniter has a low - resistance, then the voltage measured here will be close - to the LiPo battery voltage. A value greater than 3.2V is - required for a 'GO' status. - - - - - Main Igniter Voltage. This indicates whether the main - igniter has continuity. If the igniter has a low - resistance, then the voltage measured here will be close - to the LiPo battery voltage. A value greater than 3.2V is - required for a 'GO' status. - - - - - GPS Locked. This indicates whether the GPS receiver is - currently able to compute position information. GPS requires - at least 4 satellites to compute an accurate position. - - - - - GPS Ready. This indicates whether GPS has reported at least - 10 consecutive positions without losing lock. This ensures - that the GPS receiver has reliable reception from the - satellites. - - - - - The LaunchPad tab also shows the computed launch pad position - and altitude, averaging many reported positions to improve the - accuracy of the fix. - - -
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- Ascent - - This tab is shown during Boost, Fast and Coast - phases. The information displayed here helps monitor the - rocket as it heads towards apogee. - - - The height, speed and acceleration are shown along with the - maxium values for each of them. This allows you to quickly - answer the most commonly asked questions you'll hear during - flight. - - - The current latitude and longitude reported by the GPS are - also shown. Note that under high acceleration, these values - may not get updated as the GPS receiver loses position - fix. Once the rocket starts coasting, the receiver should - start reporting position again. - - - Finally, the current igniter voltages are reported as in the - Launch Pad tab. This can help diagnose deployment failures - caused by wiring which comes loose under high acceleration. - -
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- Descent - - Once the rocket has reached apogee and (we hope) activated the - apogee charge, attention switches to tracking the rocket on - the way back to the ground, and for dual-deploy flights, - waiting for the main charge to fire. - - - To monitor whether the apogee charge operated correctly, the - current descent rate is reported along with the current - height. Good descent rates generally range from 15-30m/s. - - - To help locate the rocket in the sky, use the elevation and - bearing information to figure out where to look. Elevation is - in degrees above the horizon. Bearing is reported in degrees - relative to true north. Range can help figure out how big the - rocket will appear. Note that all of these values are relative - to the pad location. If the elevation is near 90°, the rocket - is over the pad, not over you. - - - Finally, the igniter voltages are reported in this tab as - well, both to monitor the main charge as well as to see what - the status of the apogee charge is. - -
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- Landed - - Once the rocket is on the ground, attention switches to - recovery. While the radio signal is generally lost once the - rocket is on the ground, the last reported GPS position is - generally within a short distance of the actual landing location. - - - The last reported GPS position is reported both by - latitude and longitude as well as a bearing and distance from - the launch pad. The distance should give you a good idea of - whether you'll want to walk or hitch a ride. Take the reported - latitude and longitude and enter them into your handheld GPS - unit and have that compute a track to the landing location. - - - Finally, the maximum height, speed and acceleration reported - during the flight are displayed for your admiring observers. - -
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- Site Map - - When the rocket gets a GPS fix, the Site Map tab will map - the rocket's position to make it easier for you to locate the - rocket, both while it is in the air, and when it has landed. The - rocket's state is indicated by colour: white for pad, red for - boost, pink for fast, yellow for coast, light blue for drogue, - dark blue for main, and black for landed. - - - The map's scale is approximately 3m (10ft) per pixel. The map - can be dragged using the left mouse button. The map will attempt - to keep the rocket roughly centred while data is being received. - - - Images are fetched automatically via the Google Maps Static API, - and are cached for reuse. If map images cannot be downloaded, - the rocket's path will be traced on a dark grey background - instead. - -
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- Save Flight Data - - TeleMetrum records flight data to its internal flash memory. - This data is recorded at a much higher rate than the telemetry - system can handle, and is not subject to radio drop-outs. As - such, it provides a more complete and precise record of the - flight. The 'Save Flight Data' button allows you to read the - flash memory and write it to disk. - - - Clicking on the 'Save Flight Data' button brings up a list of - connected TeleMetrum and TeleDongle devices. If you select a - TeleMetrum device, the flight data will be downloaded from that - device directly. If you select a TeleDongle device, flight data - will be downloaded from a TeleMetrum device connected via the - packet command link to the specified TeleDongle. See the chapter - on Packet Command Mode for more information about this. - - - The filename for the data is computed automatically from the recorded - flight date, TeleMetrum serial number and flight number - information. - -
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- Replay Flight - - Select this button and you are prompted to select a flight - record file, either a .telem file recording telemetry data or a - .eeprom file containing flight data saved from the TeleMetrum - flash memory. - - - Once a flight record is selected, the flight monitor interface - is displayed and the flight is re-enacted in real time. Check - the Monitor Flight chapter above to learn how this window operates. - -
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- Graph Data - - Select this button and you are prompted to select a flight - record file, either a .telem file recording telemetry data or a - .eeprom file containing flight data saved from the TeleMetrum - flash memory. - - - Once a flight record is selected, the acceleration (blue), - velocity (green) and altitude (red) of the flight are plotted and - displayed, measured in metric units. - - - The graph can be zoomed into a particular area by clicking and - dragging down and to the right. Once zoomed, the graph can be - reset by clicking and dragging up and to the left. Holding down - control and clicking and dragging allows the graph to be panned. - The right mouse button causes a popup menu to be displayed, giving - you the option save or print the plot. - - - Note that telemetry files will generally produce poor graphs - due to the lower sampling rate and missed telemetry packets, - and will also often have significant amounts of data received - while the rocket was waiting on the pad. Use saved flight data - for graphing where possible. - -
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- Export Data - - This tool takes the raw data files and makes them available for - external analysis. When you select this button, you are prompted to select a flight - data file (either .eeprom or .telem will do, remember that - .eeprom files contain higher resolution and more continuous - data). Next, a second dialog appears which is used to select - where to write the resulting file. It has a selector to choose - between CSV and KML file formats. - -
- Comma Separated Value Format - - This is a text file containing the data in a form suitable for - import into a spreadsheet or other external data analysis - tool. The first few lines of the file contain the version and - configuration information from the TeleMetrum device, then - there is a single header line which labels all of the - fields. All of these lines start with a '#' character which - most tools can be configured to skip over. - - - The remaining lines of the file contain the data, with each - field separated by a comma and at least one space. All of - the sensor values are converted to standard units, with the - barometric data reported in both pressure, altitude and - height above pad units. - -
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- Keyhole Markup Language (for Google Earth) - - This is the format used by - Googleearth to provide an overlay within that - application. With this, you can use Googleearth to see the - whole flight path in 3D. - -
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- Configure TeleMetrum - - Select this button and then select either a TeleMetrum or - TeleDongle Device from the list provided. Selecting a TeleDongle - device will use Packet Comamnd Mode to configure remote - TeleMetrum device. Learn how to use this in the Packet Command - Mode chapter. - - - The first few lines of the dialog provide information about the - connected TeleMetrum device, including the product name, - software version and hardware serial number. Below that are the - individual configuration entries. - - - At the bottom of the dialog, there are four buttons: - - - - - Save. This writes any changes to the TeleMetrum - configuration parameter block in flash memory. If you don't - press this button, any changes you make will be lost. - - - - - Reset. This resets the dialog to the most recently saved values, - erasing any changes you have made. - - - - - Reboot. This reboots the TeleMetrum device. Use this to - switch from idle to pad mode by rebooting once the rocket is - oriented for flight. - - - - - Close. This closes the dialog. Any unsaved changes will be - lost. - - - - - The rest of the dialog contains the parameters to be configured. - -
- Main Deploy Altitude - - This sets the altitude (above the recorded pad altitude) at - which the 'main' igniter will fire. The drop-down menu shows - some common values, but you can edit the text directly and - choose whatever you like. If the apogee charge fires below - this altitude, then the main charge will fire two seconds - after the apogee charge fires. - -
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- Apogee Delay - - When flying redundant electronics, it's often important to - ensure that multiple apogee charges don't fire at precisely - the same time as that can overpressurize the apogee deployment - bay and cause a structural failure of the airframe. The Apogee - Delay parameter tells the flight computer to fire the apogee - charge a certain number of seconds after apogee has been - detected. - -
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- Radio Channel - - This configures which of the 10 radio channels to use for both - telemetry and packet command mode. Note that if you set this - value via packet command mode, you will have to reconfigure - the TeleDongle channel before you will be able to use packet - command mode again. - -
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- Radio Calibration - - The radios in every Altus Metrum device are calibrated at the - factory to ensure that they transmit and receive on the - specified frequency for each channel. You can adjust that - calibration by changing this value. To change the TeleDongle's - calibration, you must reprogram the unit completely. - -
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- Callsign - - This sets the callsign included in each telemetry packet. Set this - as needed to conform to your local radio regulations. - -
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- Configure AltosUI - - This button presents a dialog so that you can configure the AltosUI global settings. - -
- Voice Settings - - AltosUI provides voice annoucements during flight so that you - can keep your eyes on the sky and still get information about - the current flight status. However, sometimes you don't want - to hear them. - - - - Enable—turns all voice announcements on and off - - - - Test Voice—Plays a short message allowing you to verify - that the audio systme is working and the volume settings - are reasonable - - - -
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- Log Directory - - AltosUI logs all telemetry data and saves all TeleMetrum flash - data to this directory. This directory is also used as the - staring point when selecting data files for display or export. - - - Click on the directory name to bring up a directory choosing - dialog, select a new directory and click 'Select Directory' to - change where AltosUI reads and writes data files. - -
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- Callsign - - This value is used in command packet mode and is transmitted - in each packet sent from TeleDongle and received from - TeleMetrum. It is not used in telemetry mode as that transmits - packets only from TeleMetrum to TeleDongle. Configure this - with the AltosUI operators callsign as needed to comply with - your local radio regulations. - -
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- Flash Image - - This reprograms any Altus Metrum device by using a TeleMetrum or - TeleDongle as a programming dongle. Please read the directions - for connecting the programming cable in the main TeleMetrum - manual before reading these instructions. - - - Once you have the programmer and target devices connected, - push the 'Flash Image' button. That will present a dialog box - listing all of the connected devices. Carefully select the - programmer device, not the device to be programmed. - - - Next, select the image to flash to the device. These are named - with the product name and firmware version. The file selector - will start in the directory containing the firmware included - with the AltosUI package. Navigate to the directory containing - the desired firmware if it isn't there. - - - Next, a small dialog containing the device serial number and - RF calibration values should appear. If these values are - incorrect (possibly due to a corrupted image in the device), - enter the correct values here. - - - Finally, a dialog containing a progress bar will follow the - programming process. - - - When programming is complete, the target device will - reboot. Note that if the target device is connected via USB, you - will have to unplug it and then plug it back in for the USB - connection to reset so that you can communicate with the device - again. - -
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- Fire Igniter - - This activates the igniter circuits in TeleMetrum to help test - recovery systems deployment. Because this command can operate - over the Packet Command Link, you can prepare the rocket as - for flight and then test the recovery system without needing - to snake wires inside the airframe. - - - Selecting the 'Fire Igniter' button brings up the usual device - selection dialog. Pick the desired TeleDongle or TeleMetrum - device. This brings up another window which shows the current - continutity test status for both apogee and main charges. - - - Next, select the desired igniter to fire. This will enable the - 'Arm' button. - - - Select the 'Arm' button. This enables the 'Fire' button. The - word 'Arm' is replaced by a countdown timer indicating that - you have 10 seconds to press the 'Fire' button or the system - will deactivate, at which point you start over again at - selecting the desired igniter. - -
- - - Using Altus Metrum Products -
- Being Legal - - First off, in the US, you need an amateur radio license or - other authorization to legally operate the radio transmitters that are part - of our products. - -
- In the Rocket - - In the rocket itself, you just need a TeleMetrum board and - a LiPo rechargeable battery. An 860mAh battery weighs less than a 9V - alkaline battery, and will run a TeleMetrum for hours. - - - By default, we ship TeleMetrum with a simple wire antenna. If your - electronics bay or the airframe it resides within is made of carbon fiber, - which is opaque to RF signals, you may choose to have an SMA connector - installed so that you can run a coaxial cable to an antenna mounted - elsewhere in the rocket. - -
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- On the Ground - - To receive the data stream from the rocket, you need an antenna and short - feedline connected to one of our TeleDongle units. The - TeleDongle in turn plugs directly into the USB port on a notebook - computer. Because TeleDongle looks like a simple serial port, your computer - does not require special device drivers... just plug it in. - - - The GUI tool, AltosUI, is written in Java and runs across - Linux, Mac OS and Windows. There's also a suite of C tools - for Linux which can perform most of the same tasks. - - - After the flight, you can use the RF link to extract the more detailed data - logged in the rocket, or you can use a mini USB cable to plug into the - TeleMetrum board directly. Pulling out the data without having to open up - the rocket is pretty cool! A USB cable is also how you charge the LiPo - battery, so you'll want one of those anyway... the same cable used by lots - of digital cameras and other modern electronic stuff will work fine. - - - If your rocket lands out of sight, you may enjoy having a hand-held GPS - receiver, so that you can put in a waypoint for the last reported rocket - position before touch-down. This makes looking for your rocket a lot like - Geo-Cacheing... just go to the waypoint and look around starting from there. - - - You may also enjoy having a ham radio "HT" that covers the 70cm band... you - can use that with your antenna to direction-find the rocket on the ground - the same way you can use a Walston or Beeline tracker. This can be handy - if the rocket is hiding in sage brush or a tree, or if the last GPS position - doesn't get you close enough because the rocket dropped into a canyon, or - the wind is blowing it across a dry lake bed, or something like that... Keith - and Bdale both currently own and use the Yaesu VX-7R at launches. - - - So, to recap, on the ground the hardware you'll need includes: - - - an antenna and feedline - - - a TeleDongle - - - a notebook computer - - - optionally, a handheld GPS receiver - - - optionally, an HT or receiver covering 435 Mhz - - - - - The best hand-held commercial directional antennas we've found for radio - direction finding rockets are from - - Arrow Antennas. - - The 440-3 and 440-5 are both good choices for finding a - TeleMetrum-equipped rocket when used with a suitable 70cm HT. - -
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- Data Analysis - - Our software makes it easy to log the data from each flight, both the - telemetry received over the RF link during the flight itself, and the more - complete data log recorded in the DataFlash memory on the TeleMetrum - board. Once this data is on your computer, our postflight tools make it - easy to quickly get to the numbers everyone wants, like apogee altitude, - max acceleration, and max velocity. You can also generate and view a - standard set of plots showing the altitude, acceleration, and - velocity of the rocket during flight. And you can even export a data file - useable with Google Maps and Google Earth for visualizing the flight path - in two or three dimensions! - - - Our ultimate goal is to emit a set of files for each flight that can be - published as a web page per flight, or just viewed on your local disk with - a web browser. - -
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- Future Plans - - In the future, we intend to offer "companion boards" for the rocket that will - plug in to TeleMetrum to collect additional data, provide more pyro channels, - and so forth. A reference design for a companion board will be documented - soon, and will be compatible with open source Arduino programming tools. - - - We are also working on the design of a hand-held ground terminal that will - allow monitoring the rocket's status, collecting data during flight, and - logging data after flight without the need for a notebook computer on the - flight line. Particularly since it is so difficult to read most notebook - screens in direct sunlight, we think this will be a great thing to have. - - - Because all of our work is open, both the hardware designs and the software, - if you have some great idea for an addition to the current Altus Metrum family, - feel free to dive in and help! Or let us know what you'd like to see that - we aren't already working on, and maybe we'll get excited about it too... - -
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