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-<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
- "/usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd">
-<book>
- <title>The Altus Metrum System</title>
- <subtitle>Owner's Manual for TeleMetrum and TeleDongle Devices</subtitle>
- <bookinfo>
- <author>
- <firstname>Bdale</firstname>
- <surname>Garbee</surname>
- </author>
- <author>
- <firstname>Keith</firstname>
- <surname>Packard</surname>
- </author>
- <author>
- <firstname>Bob</firstname>
- <surname>Finch</surname>
- </author>
- <author>
- <firstname>Anthony</firstname>
- <surname>Towns</surname>
- </author>
- <copyright>
- <year>2010</year>
- <holder>Bdale Garbee and Keith Packard</holder>
- </copyright>
- <legalnotice>
- <para>
- This document is released under the terms of the
- <ulink url="http://creativecommons.org/licenses/by-sa/3.0/">
- Creative Commons ShareAlike 3.0
- </ulink>
- license.
- </para>
- </legalnotice>
- <revhistory>
- <revision>
- <revnumber>0.8</revnumber>
- <date>24 November 2010</date>
- <revremark>Updated for software version 0.8 </revremark>
- </revision>
- </revhistory>
- </bookinfo>
- <acknowledgements>
- <para>
- 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!
- </para>
- <para>
- 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.
- </para>
- <para>
- Have fun using these products, and we hope to meet all of you
- out on the rocket flight line somewhere.
- <literallayout>
-Bdale Garbee, KB0G
-NAR #87103, TRA #12201
-
-Keith Packard, KD7SQG
-NAR #88757, TRA #12200
- </literallayout>
- </para>
- </acknowledgements>
- <chapter>
- <title>Introduction and Overview</title>
- <para>
- 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!
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </chapter>
- <chapter>
- <title>Getting Started</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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
- <ulink url="http://altusmetrum.org/AltOS"/>.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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'.)
- </para>
- <para>
- 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.)
- </para>
- <para>
- 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!
- </para>
- <section>
- <title>FAQ</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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'.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- </chapter>
- <chapter>
- <title>Specifications</title>
- <itemizedlist>
- <listitem>
- <para>
- Recording altimeter for model rocketry.
- </para>
- </listitem>
- <listitem>
- <para>
- Supports dual deployment (can fire 2 ejection charges).
- </para>
- </listitem>
- <listitem>
- <para>
- 70cm ham-band transceiver for telemetry downlink.
- </para>
- </listitem>
- <listitem>
- <para>
- Barometric pressure sensor good to 45k feet MSL.
- </para>
- </listitem>
- <listitem>
- <para>
- 1-axis high-g accelerometer for motor characterization, capable of
- +/- 50g using default part.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board, integrated GPS receiver with 5hz update rate capability.
- </para>
- </listitem>
- <listitem>
- <para>
- On-board 1 megabyte non-volatile memory for flight data storage.
- </para>
- </listitem>
- <listitem>
- <para>
- USB interface for battery charging, configuration, and data recovery.
- </para>
- </listitem>
- <listitem>
- <para>
- Fully integrated support for LiPo rechargeable batteries.
- </para>
- </listitem>
- <listitem>
- <para>
- Uses LiPo to fire e-matches, support for optional separate pyro
- battery if needed.
- </para>
- </listitem>
- <listitem>
- <para>
- 2.75 x 1 inch board designed to fit inside 29mm airframe coupler tube.
- </para>
- </listitem>
- </itemizedlist>
- </chapter>
- <chapter>
- <title>Handling Precautions</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- As with all other rocketry electronics, TeleMetrum must be protected
- from exposure to corrosive motor exhaust and ejection charge gasses.
- </para>
- </chapter>
- <chapter>
- <title>Hardware Overview</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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]
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </chapter>
- <chapter>
- <title>System Operation</title>
- <section>
- <title>Firmware Modes </title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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!
- </para>
- </section>
- <section>
- <title>GPS </title>
- <para>
- 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!
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Ground Testing </title>
- <para>
- 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!
- </para>
- <para>
- 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.
- </para>
- <para>
- 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'.
- </para>
- </section>
- <section>
- <title>Radio Link </title>
- <para>
- 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.
- </para>
- <para>
- 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...
- </para>
- <para>
- 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!
- </para>
- </section>
- <section>
- <title>Configurable Parameters</title>
- <para>
- 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.
- </para>
- <section>
- <title>Radio Channel</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Apogee Delay</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Main Deployment Altitude</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- </section>
- <section>
- <title>Calibration</title>
- <para>
- There are only two calibrations required for a TeleMetrum board, and
- only one for TeleDongle.
- </para>
- <section>
- <title>Radio Frequency</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Accelerometer</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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).
- </para>
- </section>
- </section>
-
-
-
- <section>
- <title>Updating Device Firmware</title>
- <para>
- 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.
- </para>
- <para>
- 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 <ulink url="http://www.altusmetrum.org/AltOS/"/>.
- </para>
- <para>
- We recommend updating TeleMetrum first, before updating TeleDongle.
- </para>
- <section>
- <title>Updating TeleMetrum Firmware</title>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- 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.
- </listitem>
- <listitem>
- Take the 2 screws out of the TeleDongle case to get access
- to the circuit board.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- Attach a battery to the TeleMetrum board.
- </listitem>
- <listitem>
- Plug the TeleDongle into your computer's USB port, and power
- up the TeleMetrum.
- </listitem>
- <listitem>
- Run AltosUI, and select 'Flash Image' from the File menu.
- </listitem>
- <listitem>
- Pick the TeleDongle device from the list, identifying it as the
- programming device.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- Hit the 'OK' button and the software should proceed to flash
- the TeleMetrum with new firmware, showing a progress bar.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- If something goes wrong, give it another try.
- </listitem>
- </orderedlist>
- </section>
- <section>
- <title>Updating TeleDongle Firmware</title>
- <para>
- Updating TeleDongle's firmware is just like updating TeleMetrum
- firmware, but you switch which board is the programmer and which
- is the programming target.
- </para>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- 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.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- Take the 2 screws out of the TeleDongle case to get access
- to the circuit board.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- Attach a battery to the TeleMetrum board.
- </listitem>
- <listitem>
- Plug both TeleMetrum and TeleDongle into your computer's USB
- ports, and power up the TeleMetrum.
- </listitem>
- <listitem>
- Run AltosUI, and select 'Flash Image' from the File menu.
- </listitem>
- <listitem>
- Pick the TeleMetrum device from the list, identifying it as the
- programming device.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- Hit the 'OK' button and the software should proceed to flash
- the TeleDongle with new firmware, showing a progress bar.
- </listitem>
- <listitem>
- 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.
- </listitem>
- <listitem>
- If something goes wrong, give it another try.
- </listitem>
- </orderedlist>
- <para>
- 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.
- </para>
- </section>
- </section>
-
-
-
- </chapter>
- <chapter>
-
- <title>AltosUI</title>
- <para>
- 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.
- </para>
- <section>
- <title>Packet Command Mode</title>
- <subtitle>Controlling TeleMetrum Over The Radio Link</subtitle>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <itemizedlist>
- <listitem>
- <para>
- Save Flight Data—Recover flight data from the rocket without
- opening it up.
- </para>
- </listitem>
- <listitem>
- <para>
- 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.
- </para>
- </listitem>
- <listitem>
- <para>
- 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.
- </para>
- </listitem>
- </itemizedlist>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Monitor Flight</title>
- <subtitle>Receive, Record and Display Telemetry Data</subtitle>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- Below the TeleDongle channel selector, the window contains a few
- significant pieces of information about the TeleMetrum providing
- the telemetry data stream:
- </para>
- <itemizedlist>
- <listitem>
- <para>The TeleMetrum callsign</para>
- </listitem>
- <listitem>
- <para>The TeleMetrum serial number</para>
- </listitem>
- <listitem>
- <para>The flight number. Each TeleMetrum remembers how many
- times it has flown.
- </para>
- </listitem>
- <listitem>
- <para>
- The rocket flight state. Each flight passes through several
- states including Pad, Boost, Fast, Coast, Drogue, Main and
- Landed.
- </para>
- </listitem>
- <listitem>
- <para>
- 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.
- </para>
- </listitem>
- </itemizedlist>
- <para>
- 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.
- </para>
- <section>
- <title>Launch Pad</title>
- <para>
- 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:
- <itemizedlist>
- <listitem>
- <para>
- 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.
- </para>
- </listitem>
- <listitem>
- <para>
- 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.
- </para>
- </listitem>
- <listitem>
- <para>
- 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.
- </para>
- </listitem>
- <listitem>
- <para>
- 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.
- </para>
- </listitem>
- <listitem>
- <para>
- 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.
- </para>
- </listitem>
- </itemizedlist>
- <para>
- The LaunchPad tab also shows the computed launch pad position
- and altitude, averaging many reported positions to improve the
- accuracy of the fix.
- </para>
- </para>
- </section>
- <section>
- <title>Ascent</title>
- <para>
- This tab is shown during Boost, Fast and Coast
- phases. The information displayed here helps monitor the
- rocket as it heads towards apogee.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Descent</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Landed</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- Finally, the maximum height, speed and acceleration reported
- during the flight are displayed for your admiring observers.
- </para>
- </section>
- <section>
- <title>Site Map</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- </section>
- <section>
- <title>Save Flight Data</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- The filename for the data is computed automatically from the recorded
- flight date, TeleMetrum serial number and flight number
- information.
- </para>
- </section>
- <section>
- <title>Replay Flight</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Graph Data</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Export Data</title>
- <para>
- 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.
- </para>
- <section>
- <title>Comma Separated Value Format</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Keyhole Markup Language (for Google Earth)</title>
- <para>
- 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.
- </para>
- </section>
- </section>
- <section>
- <title>Configure TeleMetrum</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- At the bottom of the dialog, there are four buttons:
- </para>
- <itemizedlist>
- <listitem>
- <para>
- 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.
- </para>
- </listitem>
- <listitem>
- <para>
- Reset. This resets the dialog to the most recently saved values,
- erasing any changes you have made.
- </para>
- </listitem>
- <listitem>
- <para>
- Reboot. This reboots the TeleMetrum device. Use this to
- switch from idle to pad mode by rebooting once the rocket is
- oriented for flight.
- </para>
- </listitem>
- <listitem>
- <para>
- Close. This closes the dialog. Any unsaved changes will be
- lost.
- </para>
- </listitem>
- </itemizedlist>
- <para>
- The rest of the dialog contains the parameters to be configured.
- </para>
- <section>
- <title>Main Deploy Altitude</title>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Apogee Delay</title>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Radio Channel</title>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Radio Calibration</title>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Callsign</title>
- <para>
- This sets the callsign included in each telemetry packet. Set this
- as needed to conform to your local radio regulations.
- </para>
- </section>
- </section>
- <section>
- <title>Configure AltosUI</title>
- <para>
- This button presents a dialog so that you can configure the AltosUI global settings.
- </para>
- <section>
- <title>Voice Settings</title>
- <para>
- 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.
- </para>
- <itemizedlist>
- <listitem>
- <para>Enable—turns all voice announcements on and off</para>
- </listitem>
- <listitem>
- <para>
- Test Voice—Plays a short message allowing you to verify
- that the audio systme is working and the volume settings
- are reasonable
- </para>
- </listitem>
- </itemizedlist>
- </section>
- <section>
- <title>Log Directory</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Callsign</title>
- <para>
- 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.
- </para>
- </section>
- </section>
- <section>
- <title>Flash Image</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- Finally, a dialog containing a progress bar will follow the
- programming process.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Fire Igniter</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- Next, select the desired igniter to fire. This will enable the
- 'Arm' button.
- </para>
- <para>
- 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.
- </para>
- </section>
- </chapter>
- <chapter>
- <title>Using Altus Metrum Products</title>
- <section>
- <title>Being Legal</title>
- <para>
- First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
- other authorization to legally operate the radio transmitters that are part
- of our products.
- </para>
- <section>
- <title>In the Rocket</title>
- <para>
- In the rocket itself, you just need a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> board and
- a LiPo rechargeable battery. An 860mAh battery weighs less than a 9V
- alkaline battery, and will run a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> for hours.
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>On the Ground</title>
- <para>
- To receive the data stream from the rocket, you need an antenna and short
- feedline connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- So, to recap, on the ground the hardware you'll need includes:
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- an antenna and feedline
- </listitem>
- <listitem>
- a TeleDongle
- </listitem>
- <listitem>
- a notebook computer
- </listitem>
- <listitem>
- optionally, a handheld GPS receiver
- </listitem>
- <listitem>
- optionally, an HT or receiver covering 435 Mhz
- </listitem>
- </orderedlist>
- </para>
- <para>
- The best hand-held commercial directional antennas we've found for radio
- direction finding rockets are from
- <ulink url="http://www.arrowantennas.com/" >
- Arrow Antennas.
- </ulink>
- The 440-3 and 440-5 are both good choices for finding a
- TeleMetrum-equipped rocket when used with a suitable 70cm HT.
- </para>
- </section>
- <section>
- <title>Data Analysis</title>
- <para>
- 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!
- </para>
- <para>
- 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.
- </para>
- </section>
- <section>
- <title>Future Plans</title>
- <para>
- 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.
- </para>
- <para>
- 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.
- </para>
- <para>
- 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...
- </para>
- </section>
- </section>
- </chapter>
-</book>
-
projects / fw / altos / blobdiff