<revhistory>
<revision>
<revnumber>1.0</revnumber>
- <date>10 August 2011</date>
+ <date>24 August 2011</date>
<revremark>
Updated for software version 1.0. Note that 1.0 represents a
- telemetry format change, meaning both ends of a link (TeleMetrum/TeleMini and
- TeleDongle) must be updated or communications will fail.
+ telemetry format change, meaning both ends of a link
+ (TeleMetrum/TeleMini and TeleDongle) must be updated or
+ communications will fail.
</revremark>
</revision>
<revision>
<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!
+ Kit" which formed the basis of the original Getting Started chapter
+ in this manual. Bob was one of our first customers for a production
+ TeleMetrum, and his continued enthusiasm and contributions
+ are immensely gratifying and highly 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
+ And thanks to Anthony (AJ) Towns for major contributions including
+ the AltosUI graphing and site map code and associated documentation.
+ Free software means that our customers and friends can become our
collaborators, and we certainly appreciate this level of
- contribution.
+ contribution!
</para>
<para>
Have fun using these products, and we hope to meet all of you
future as you wish!
</para>
<para>
- The first device created for our community is TeleMetrum, a dual
+ The first device created for our community was 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>
The newest device is TeleMini, a dual deploy altimeter with
radio telemetry and radio direction finding. This device is only
- 13mm by 38mm (½ inch by 1½ inches) and can fit easily in an 18mm airframe.
+ 13mm by 38mm (½ inch by 1½ inches) and can fit easily in an 18mm
+ air-frame.
</para>
<para>
- Complementing TeleMetrum and TeleMini is TeleDongle, a USB to RF interface for
- communicating with the altimeters. Combined with your choice of antenna and
+ Complementing TeleMetrum and TeleMini is TeleDongle, a USB to RF
+ interface for communicating with the altimeters. 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
The TeleMetrum battery can be charged 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
+ 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.
<para>
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
+ 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
</para>
<para>
The TeleMini battery can be charged by disconnecting it from the
- TeleMini board and plugging it into the battery charger board,
- and connecting that via a USB cable to a laptop or other USB
+ TeleMini board and plugging it into a standalone battery charger
+ board, and connecting that via a USB cable to a laptop or other USB
power source
</para>
<para>
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.
+ existing USB modem driver will work. We therefore recommend installing
+ our software before plugging in TeleDongle if you are using a Windows
+ computer. 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
+ Next you should obtain and install the AltOS software. These include
the AltosUI ground station program, current firmware images for
- TeleMetrum, TeleMini 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.
+ TeleMetrum, TeleMini and TeleDongle, and a number of standalone
+ utilities that are rarely needed. Pre-built binary packages are
+ available for Linux, Microsoft Windows, and recent MacOSX versions.
+ Full source code and build instructions are also available.
The latest version may always be downloaded from
<ulink url="http://altusmetrum.org/AltOS"/>.
</para>
+ </chapter>
+ <chapter>
+ <title>Handling Precautions</title>
<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>
- TeleMini can be communicated with through a TeleDongle device
- over the radio link. When first booted, TeleMini listens for a
- TeleDongle device and if it receives a packet, it goes into
- 'idle' mode. Otherwise, it goes into 'pad' mode and waits to be
- launched. The easiest way to get it talking is to start the
- communication link on the TeleDongle and the power up the
- TeleMini board.
- </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>
- All of the Altus Metrum devices 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 Flash memory; TeleDongle doesn't provide any storage
- for these options and so they'll all be lost when you unplug it.
+ All Altus Metrum products are sophisticated electronic devices.
+ When handled gently and properly installed in an air-frame, they
+ will deliver impressive results. However, as with all electronic
+ devices, there are some precautions you must take.
</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.
+ The Lithium Polymer rechargeable batteries 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 air-frame. We
+ often wrap them in suitable scraps of closed-cell packing foam before
+ strapping them down, for example.
</para>
<para>
- Note that the 'reboot' command, which is very useful on the altimeters,
- will likely just cause problems with the dongle. The *correct* way
- to reset the dongle is just to unplug and re-plug it.
+ The barometric sensors used on both TeleMetrum and TeleMini are
+ sensitive to sunlight. In normal TeleMetrum 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 an air-frame with a
+ see-through plastic payload bay. It is particularly important to
+ consider this with TeleMini, both because the baro sensor is on the
+ "top" of the board, and because many model rockets with payload bays
+ use clear plastic for the payload bay! Replacing these with an opaque
+ cardboard tube, painting them, or wrapping them with a layer of masking
+ tape are all reasonable approaches to keep the sensor out of direct
+ sunlight.
</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
- between an altimeter and 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.
+ The 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, and also by having a
+ suitable static vent to outside air.
</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 altimeters
- can be placed in. TeleMetrum uses the position of the device when booting
- up will determine whether the unit is in "pad" or "idle" mode. TeleMini
- enters "idle" mode when it receives a command packet within the first 5 seconds
- of being powered up, otherwise it enters "pad" mode.
+ As with all other rocketry electronics, Altus Metrum altimeters must
+ be protected from exposure to corrosive motor exhaust and ejection
+ charge gasses.
</para>
+ </chapter>
+ <chapter>
+ <title>Hardware Overview</title>
<para>
- You can access an altimeter 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 altimeter. 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.
+ TeleMetrum is a 1 inch by 2.75 inch circuit board. It was designed to
+ fit inside coupler for 29mm air-frame tubing, but using it in a tube that
+ small in diameter may require some creativity in mounting and wiring
+ to succeed! The presence of an accelerometer means TeleMetrum should
+ be aligned along the flight axis of the airframe, and by default the 1/4
+ wave UHF wire antenna should be on the nose-cone end of the board. The
+ antenna wire 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, meaning an ideal "simple" avionics
+ bay for TeleMetrum should have at least 10 inches of interior length.
</para>
<para>
- Using this rf link allows you to configure the altimeter, 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 altimeter 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.
+ TeleMini is a 0.5 inch by 1.5 inch circuit board. It was designed to
+ fit inside an 18mm air-frame tube, but using it in a tube that
+ small in diameter may require some creativity in mounting and wiring
+ to succeed! Since there is no accelerometer, TeleMini can be mounted
+ in any convenient orientation. The default 1/4
+ wave UHF wire antenna attached to the center of one 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
+ other end of the board, meaning an ideal "simple" avionics
+ bay for TeleMini should have at least 9 inches of interior length.
</para>
<para>
- On TeleMetrum, the GPS will eventually 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.
+ A typical TeleMetrum or TeleMini installation 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>
- The altimeters provide RDF (radio direction finding) tones on
- the pad, during descent and after landing. These can be used to
- locate the rocket using a directional antenna; the signal
- strength providing an indication of the direction from receiver to rocket.
+ By default, we use the unregulated output of the Li-Po 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, check out the "External Pyro Battery" section in this
+ manual for instructions on how to wire that up. The altimeters are
+ designed to work with an external pyro battery of no more than 15 volts.
</para>
<para>
- TeleMetrum also provides GPS trekking data, which can further simplify
- 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'.)
+ Ejection charges are wired directly to the screw terminal block
+ at the aft end of the altimeter. You'll need a very small straight
+ blade screwdriver for these screws, such as you might find in a
+ jeweler's screwdriver set.
</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.)
+ TeleMetrum also uses the screw terminal block for the power
+ switch leads. On TeleMini, the power switch leads are soldered
+ directly to the board and can be connected directly to a switch.
</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!
+ For most air-frames, the integrated antennas are more than
+ adequate. However, if you are installing in a carbon-fiber or
+ metal electronics bay which is opaque to RF signals, you may need to
+ use off-board external antennas instead. In this case, you can
+ order an altimeter with an SMA connector for the UHF antenna
+ connection, and, on TeleMetrum, 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>FAQ</title>
+ <title>Firmware Modes </title>
<para>
- 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.
+ The AltOS firmware build for the altimeters has two
+ fundamental modes, "idle" and "flight". Which of these modes
+ the firmware operates in is determined at start up time. For
+ TeleMetrum, the mode is controlled 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. Since TeleMini doesn't have an accelerometer we can
+ use to determine orientation, "idle" mode is selected when the
+ board receives a command packet within the first five seconds
+ of operation; if no packet is received, the board enters
+ "flight" mode.
</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.
+ At power on, you will hear three beeps or see three flashes
+ ("S" in Morse code for start up) and then a pause while
+ the altimeter completes initialization and self test, and decides
+ which mode to enter next.
</para>
<para>
- The amber LED (on the TeleMetrum) 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.
+ In flight or "pad" mode, the altimeter engages the flight
+ state machine, goes into transmit-only mode to
+ send telemetry, and waits for launch to be detected.
+ Flight mode is indicated by an "di-dah-dah-dit" ("P" for pad)
+ on the beeper or lights, followed by beeps or flashes
+ indicating the state of the pyrotechnic igniter continuity.
+ One beep/flash indicates apogee continuity, two beeps/flashes
+ indicate main continuity, three beeps/flashes indicate both
+ apogee and main continuity, and one longer "brap" sound or
+ rapidly alternating lights indicates no continuity. For a
+ dual deploy flight, make sure you're getting three beeps or
+ flashes before launching! For apogee-only or motor eject
+ flights, do what makes sense.
</para>
<para>
- There are no "dit-dah-dah-dit" sound or lights like the manual mentions?
- That's the "pad" mode. Weak batteries might be the problem.
- It is also possible that the Telemetrum is horizontal and the output
- is instead a "dit-dit" meaning 'idle'. For TeleMini, it's possible that
- it received a command packet which would have left it in "pad" mode.
+ If idle mode is entered, you will hear an audible "di-dit" or see
+ two short flashes ("I" for idle), and the flight state machine is
+ disengaged, thus no ejection charges will fire. The altimeters also
+ listen for the radio link when in idle mode for requests sent via
+ TeleDongle. Commands can be issued to a TeleMetrum in idle mode
+ over either
+ USB or the radio link equivalently. TeleMini only has the radio link.
+ Idle mode is useful for configuring the altimeter, for extracting data
+ from the on-board storage chip after flight, and for ground testing
+ pyro charges.
</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.
+ One "neat trick" of particular value when TeleMetrum is used with
+ very large air-frames, 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 air-frame to launch position, and issue a 'reset' command
+ via TeleDongle over the radio link to cause the altimeter to reboot and
+ come up in 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>
- 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.
+ TeleMetrum includes a complete GPS receiver. A complete explanation
+ of how GPS works is beyond the scope of this manual, but 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
+ battery is connected. This allows the receiver to "warm start" on
+ the launch rail much faster than if every power-on were a GPS
+ "cold start". In typical operations, powering up TeleMetrum
+ on the flight line in idle mode while performing final air-frame
+ 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>
- </chapter>
- <chapter>
- <title>Specifications</title>
<section>
- <title>TeleMetrum Specifications</title>
+ <title>Controlling An Altimeter Over The Radio Link</title>
+ <para>
+ One of the unique features of the Altus Metrum system is
+ the ability to create a two way command link between TeleDongle
+ and an altimeter using the digital radio transceivers built into
+ each device. This allows you to interact with the altimeter 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 radio
+ link. TeleMini doesn't provide a USB connector and so it is
+ always communicated with over radio. Select the appropriate
+ TeleDongle device when the list of devices is presented and
+ AltosUI will interact with an altimeter over the radio link.
+ </para>
+ <para>
+ One oddity in the current interface is how AltosUI selects the
+ frequency for radio communications. Instead of providing
+ an interface to specifically configure the frequency, it uses
+ whatever frequency 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, and pick the
+ appropriate TeleDongle device. Once the flight monitoring
+ window is open, select the desired frequency and then close it
+ down again. All radio communications will now use that frequency.
+ </para>
<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, can be modiied to support
- 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>
- </section>
- <section>
- <title>TeleMini 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>
- On-board 5 kilobyte non-volatile memory for flight data storage.
- </para>
- </listitem>
- <listitem>
- <para>
- RF interface for battery charging, configuration, and data recovery.
- </para>
- </listitem>
- <listitem>
- <para>
- Support for LiPo rechargeable batteries, using an external charger.
- </para>
- </listitem>
- <listitem>
- <para>
- Uses LiPo to fire e-matches, can be modiied to support
- optional separate pyro battery if needed.
- </para>
- </listitem>
- <listitem>
- <para>
- 1.5 x .5 inch board designed to fit inside 18mm airframe coupler tube.
- </para>
- </listitem>
+ <listitem>
+ <para>
+ Save Flight Data—Recover flight data from the rocket without
+ opening it up.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Configure altimeter apogee delays or main deploy heights
+ to respond to changing launch conditions. You can also
+ 'reboot' the altimeter. Use this to remotely enable the
+ flight computer by turning TeleMetrum on in "idle" mode,
+ then once the air-frame is oriented for launch, you can
+ reboot the altimeter 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 air-frame. Simply assembly the
+ rocket as if for flight with the apogee and main charges
+ loaded, then remotely command the altimeter to fire the
+ igniters.
+ </para>
+ </listitem>
</itemizedlist>
- </section>
- </chapter>
- <chapter>
- <title>Handling Precautions</title>
- <para>
- All Altus Metrum products are sophisticated electronic device. When handled gently and
- properly installed in an airframe, theywill deliver impressive results.
- However, like all electronic devices, there are some precautions you
- must take.
- </para>
- <para>
- The Lithium Polymer rechargeable batteries 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 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 an airframe with a
- see-through plastic payload bay.
- </para>
- <para>
- The 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, Altus Metrum altimeters 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>
- TeleMini is a 0.5 inch by 1.5 inch circuit board. It was designed to
- fit inside an 18mm airframe tube, 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 TeleMini should have at least 9 inches of interior length.
- </para>
- <para>
- A typical TeleMetrum or TeleMini installation using the on-board devices 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, check out the "External Pyro Battery"
- section in this manual for instructions on how to wire that up. The
- altimeters are designed to work with an external pyro battery of up to 15V.
- </para>
- <para>
- Ejection charges are wired directly to the screw terminal block
- at the aft end of the altimeter. 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.
- </para>
- <para>
- TeleMetrum also uses the screw terminal block for the power
- switch leads. On TeleMini, the power switch leads are soldered
- directly to the board and can be connected directly to the switch.
- </para>
- <para>
- For most airframes, the integrated antennas are more than
- adequate 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 an altimeter with an SMA connector for the UHF antenna
- connection, and, on TeleMetrum, 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 the altimeters has two
- fundamental modes, "idle" and "flight". Which of these modes
- the firmware operates in is determined at startup time. For
- TeleMetrum, the mode is controlled 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. For TeleMini, "idle" mode is selected when the
- board receives a command packet within the first five seconds
- of operation; if no packet is received, the board enters
- "flight" mode.
- </para>
- <para>
- At power on, you will hear three beeps or see three flashes
- ("S" in Morse code for startup) and then a pause while
- the altimeter completes initialization and self tests, and decides which
- mode to enter next.
- </para>
- <para>
- In flight or "pad" mode, the altimeter 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 "di-dah-dah-dit" ("P" for pad)
- on the beeper or lights, followed by beeps or flashes
- indicating the state of the pyrotechnic igniter continuity.
- One beep/flash indicates apogee continuity, two beeps/flashes
- indicate main continuity, three beeps/flashes indicate both
- apogee and main continuity, and one longer "brap" sound or
- rapidly alternating lights indicates no continuity. For a
- dual deploy flight, make sure you're getting three beeps or
- flashes 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" or see two short flashes ("I" for idle), and
- the normal flight state machine is disengaged, thus
- no ejection charges will fire. The altimeters also listen 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. TeleMini uses only the RF link.
- Idle mode is useful for configuring the altimeter, for extracting data
- from the on-board storage chip after flight, and for ground testing
- pyro charges.
+ Operation over the radio link for configuring an altimeter, ground
+ testing igniters, and so forth uses the same RF frequencies as flight
+ telemetry. To configure the desired TeleDongle frequency, select
+ the monitor flight tab, then use the frequency selector and
+ close the window before performing other desired radio operations.
</para>
<para>
- One "neat trick" of particular value when the altimeter 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
- the altimeter to reboot and come up in
- 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!
+ TeleMetrum only enables radio commanding 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>
- </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!
+ TeleMini listens for a command packet for five seconds after
+ first being turned on, if it doesn't hear anything, it enters
+ 'pad' mode, ready for flight and will no longer listen for
+ command packets. The easiest way to connect to TeleMini is to
+ initiate the command and select the TeleDongle device. At this
+ point, the TeleDongle will be attempting to communicate with
+ the TeleMini. Now turn TeleMini on, and it should immediately
+ start communicating with the TeleDongle and the desired
+ operation can be performed.
</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.
+ You can monitor the operation of the radio link by watching the
+ lights on the devices. The red LED will flash each time a packet
+ is tramsitted, while the green LED will light up on TeleDongle when
+ it is waiting to receive a packet from the altimeter.
</para>
</section>
<section>
<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- or TeleMini- equipped rocket without as
- much work as you may be accustomed to with other systems. It can
- even be fun!
+ to the bi-directional radio link central to the Altus Metrum system,
+ this can be accomplished in a TeleMetrum or TeleMini equipped rocket
+ with less work than you may be accustomed to with other systems. It
+ can even be fun!
</para>
<para>
Just prep the rocket for flight, then power up the altimeter
- in "idle" mode (placing airframe horizontal for TeleMetrum or
- starting the RF packet connection for TeleMini). This will cause the
- firmware to go into "idle" mode, in which the normal flight
+ in "idle" mode (placing air-frame horizontal for TeleMetrum or
+ selected the Configure Altimeter tab for TeleMini). 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 the altimeter 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'.
+ manual command. You can now command the altimeter to fire the apogee
+ or main charges from a safe distance using your computer and
+ TeleDongle and the Fire Igniter tab to complete ejection testing.
</para>
</section>
<section>
link.
</para>
<para>
- By design, the altimeter firmware listens for an RF connection when
+ By design, the altimeter firmware listens for the radio link when
it's in "idle mode", which
- allows us to use the RF link to configure the rocket, do things like
+ allows us to use the radio 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
+ crack open the air-frame. However, when the board is in "flight
mode", the altimeter 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
+ the rocket through
+ the radio 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
+ We don't use a 'normal packet radio' mode like APRS because they're
+ just too inefficient. The GFSK modulation we use is FSK with the
+ base-band 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!
+ 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 great 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 over time, and would of course appreciate customer feedback
+ on performance in higher altitude flights!
</para>
</section>
<section>
<title>Configurable Parameters</title>
<para>
Configuring an Altus Metrum altimeter for flight is very
- simple. Through the use of a Kalman filter, there is no need
- to set a "mach delay" . The few configurable parameters can
- all be set using a simple terminal program over the USB port
- or RF link via TeleDongle.
+ simple. Even on our baro-only TeleMini board, the use of a Kalman
+ filter means there is no need to set a "mach delay". The few
+ configurable parameters can all be set using AltosUI over USB or
+ or radio link via TeleDongle.
</para>
<section>
- <title>Radio Frequencies</title>
+ <title>Radio Frequency</title>
<para>
- The Altus Metrum boards support frequencies in the 70cm
+ Altus Metrum boards support radio frequencies in the 70cm
band. By default, the configuration interface provides a
- list of 10 common frequencies -- 100kHz channels starting at
- 434.550MHz. However, you can configure the firmware to use
+ list of 10 "standard" frequencies in 100kHz channels starting at
+ 434.550MHz. However, the firmware supports use of
any 50kHz multiple within the 70cm band. At any given
- launch, we highly recommend coordinating who will use each
- frequency and when to avoid interference. And of course, both
+ launch, we highly recommend coordinating when and by whom each
+ frequency will be used to avoid interference. And of course, both
altimeter and TeleDongle must be configured to the same
frequency to successfully communicate with each other.
</para>
- <para>
- To set the radio frequency, use the 'c R' command to specify the
- radio transceiver configuration parameter. This parameter is computed
- using the desired frequency, 'F', the radio calibration parameter, 'C' (showed by the 'c s' command) and
- the standard calibration reference frequency, 'S', (normally 434.550Mhz):
- <programlisting>
- R = F / S * C
- </programlisting>
- Round the result to the nearest integer value.
- As with all 'c' sub-commands, follow this with a 'c w' to write the
- change to the parameter block in the on-board flash on
- your altimeter board if you want the change to stay in place across reboots.
- </para>
</section>
<section>
<title>Apogee Delay</title>
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 Altus Metrum apogee detection algorithm
- fires exactly at 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.
+ The Altus Metrum apogee detection algorithm fires exactly at
+ 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 air-frames this
+ way quite happily, including Keith's successful L3 cert.
</para>
</section>
<section>
<para>
By default, the altimeter 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
+ is a good elevation for most air-frames, 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 and TeleMini.
- </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 434.550MHz, 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>
+ <title>Maximum Flight Log</title>
+ <para>
+ TeleMetrum version 1.1 has 2MB of on-board flash storage,
+ enough to hold over 40 minutes of data at full data rate
+ (100 samples/second). TeleMetrum 1.0 has 1MB of on-board
+ storage. As data are stored at a reduced rate during descent
+ (10 samples/second), there's plenty of space to store many
+ flights worth of data.
+ </para>
+ <para>
+ The on-board flash is partitioned into separate flight logs,
+ each of a fixed maximum size. Increase the maximum size of
+ each log and you reduce the number of flights that can be
+ stored. Decrease the size and TeleMetrum can store more
+ flights.
+ </para>
+ <para>
+ All of the configuration data is also stored in the flash
+ memory, which consumes 64kB on TeleMetrum v1.1 and 256B on
+ TeleMetrum v1.0. This configuration space is not available
+ for storing flight log data.
+ </para>
+ <para>
+ To compute the amount of space needed for a single flight,
+ you can multiply the expected ascent time (in seconds) by
+ 800, multiply the expected descent time (in seconds) by 80
+ and add the two together. That will slightly under-estimate
+ the storage (in bytes) needed for the flight. For instance,
+ a flight spending 20 seconds in ascent and 150 seconds in
+ descent will take about (20 * 800) + (150 * 80) = 28000
+ bytes of storage. You could store dozens of these flights in
+ the on-board flash.
+ </para>
+ <para>
+ The default size, 192kB, allows for 10 flights of storage on
+ TeleMetrum v1.1 and 5 flights on TeleMetrum v1.0. This
+ ensures that you won't need to erase the memory before
+ flying each time while still allowing more than sufficient
+ storage for each flight.
+ </para>
<para>
- when the radio calibration value is changed, the radio
- frequency value is reset to the same value, so you'll need
- to recompute and reset the radio frequency value using the
- new radio calibration value.
+ As TeleMini does not contain an accelerometer, it stores
+ data at 10 samples per second during ascent and one sample
+ per second during descent. Each sample is a two byte reading
+ from the barometer. These are stored in 5kB of
+ on-chip flash memory which can hold 256 seconds at the
+ ascent rate or 2560 seconds at the descent rate. Because of
+ the limited storage, TeleMini cannot hold data for more than
+ one flight, and so must be erased after each flight or it
+ will not capture data for subsequent flights.
</para>
</section>
<section>
- <title>TeleMetrum Accelerometer</title>
- <para>
- The TeleMerum 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>
+ <title>Ignite Mode</title>
+ <para>
+ Instead of firing one charge at apogee and another charge at
+ a fixed height above the ground, you can configure the
+ altimeter to fire both at apogee or both during
+ descent. This was added to support an airframe that has two
+ TeleMetrum computers, one in the fin can and one in the
+ nose.
+ </para>
+ <para>
+ Providing the ability to use both igniters for apogee or
+ main allows some level of redundancy without needing two
+ flight computers. In Redundant Apogee or Redundant Main
+ mode, the two charges will be fired two seconds apart.
+ </para>
+ </section>
+ <section>
+ <title>Pad Orientation</title>
+ <para>
+ TeleMetrum measures acceleration along the axis of the
+ board. Which way the board is oriented affects the sign of
+ the acceleration value. Instead of trying to guess which way
+ the board is mounted in the air frame, TeleMetrum must be
+ explicitly configured for either Antenna Up or Antenna
+ Down. The default, Antenna Up, expects the end of the
+ TeleMetrum board connected to the 70cm antenna to be nearest
+ the nose of the rocket, with the end containing the screw
+ terminals nearest the tail.
+ </para>
</section>
</section>
+ </chapter>
+ <chapter>
-
- <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 or TeleMini,
- and a TeleMetrum or other TeleDongle to program the TeleDongle
- Due to limited memory resources in the cc1111, we don't support
- programming 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>
+ <title>AltosUI</title>
<para>
- We recommend updating the altimeter first, before updating TeleDongle.
+ The AltosUI program provides a graphical user interface for
+ interacting with the Altus Metrum product family, including
+ TeleMetrum, TeleMini and TeleDongle. AltosUI can monitor telemetry data,
+ configure TeleMetrum, TeleMini 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>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-v1.1-1.0.0.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 TeleMini Firmware</title>
- <orderedlist inheritnum='inherit' numeration='arabic'>
- <listitem>
- You'll need a special 'programming cable' to reprogram the
- TeleMini. It's available on the Altus Metrum web store, or
- you can make your own using an 8-pin MicroMaTch connector on
- one end and a set of four pins on the other.
- </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-pins into the holes
- in the TeleMini circuit board. Note that the MicroMaTch
- connector has an alignment pin that goes through a hole in
- the PC board when you have the cable oriented correctly, and
- that pin 1 on the TeleMini board is marked with a square pad
- while the other pins have round pads.
- </listitem>
- <listitem>
- Attach a battery to the TeleMini board.
- </listitem>
- <listitem>
- Plug the TeleDongle into your computer's USB port, and power
- up the TeleMini
- </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>
+ <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 frequency being monitored by the TeleDongle device is
+ displayed at the top of the window. You can configure the
+ frequency by clicking on the frequency box and selecting the desired
+ frequency. AltosUI remembers the last frequency selected for each
+ TeleDongle and selects that automatically the next time you use
+ that device.
+ </para>
+ <para>
+ Below the TeleDongle frequency selector, the window contains a few
+ significant pieces of information about the altimeter providing
+ the telemetry data stream:
+ </para>
+ <itemizedlist>
<listitem>
- Select the image you want put on the TeleMini, which should have a
- name in the form telemini-v1.0-1.0.0.ihx. It should be visible
- in the default directory, if not you may have to poke around
- your system to find it.
+ <para>The configured call-sign</para>
</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.
+ <para>The device serial number</para>
</listitem>
<listitem>
- Hit the 'OK' button and the software should proceed to flash
- the TeleMini with new firmware, showing a progress bar.
+ <para>The flight number. Each altimeter remembers how many
+ times it has flown.
+ </para>
</listitem>
<listitem>
- Confirm that the TeleMini board seems to have updated ok, which you
- can do by configuring it over the RF link through the TeleDongle, or
- letting it come up in "flight" mode and listening for telemetry.
+ <para>
+ The rocket flight state. Each flight passes through several
+ states including Pad, Boost, Fast, Coast, Drogue, Main and
+ Landed.
+ </para>
</listitem>
<listitem>
- If something goes wrong, give it another try.
+ <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 receivable. The packet link uses
+ error detection and correction techniques which prevent
+ incorrect data from being reported.
+ </para>
</listitem>
- </orderedlist>
- </section>
- <section>
- <title>Updating TeleDongle Firmware</title>
- <para>
- Updating TeleDongle's firmware is just like updating TeleMetrum or TeleMini
- firmware, but you use either a TeleMetrum or another TeleDongle as the programmer.
- </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 or TeleDongle.
- </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 programmer, 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 if you're using one.
- </listitem>
- <listitem>
- Plug both the programmer and the TeleDongle into your computer's USB
- ports, and power up the programmer.
- </listitem>
- <listitem>
- Run AltosUI, and select 'Flash Image' from the File menu.
- </listitem>
- <listitem>
- Pick the programmer 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-v0.2-1.0.0.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, TeleMini and TeleDongle. AltosUI can monitor telemetry data,
- configure TeleMetrum, TeleMini 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 An Altimeter Over The Radio Link</subtitle>
- <para>
- One of the unique features of the Altus Metrum environment is
- the ability to create a two way command link between TeleDongle
- and an altimeter using the digital radio transceivers built into
- each device. This allows you to interact with the altimeter 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
- frequency for packet mode communications. Instead of providing
- an interface to specifically configure the frequency, it uses
- whatever frequency 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 frequency and then close it
- down again. All Packet Command Mode operations will now use
- that frequency.
- </para>
- <itemizedlist>
- <listitem>
- <para>
- Save Flight Data—Recover flight data from the rocket without
- opening it up.
- </para>
- </listitem>
- <listitem>
- <para>
- Configure altimeter apogee delays or main deploy heights
- to respond to changing launch conditions. You can also
- 'reboot' the altimeter. Use this to remotely enable the
- flight computer by turning TeleMetrum on in "idle" mode,
- then once the airframe is oriented for launch, you can
- reboot the altimeter 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 the altimeter to fire the
- igniters.
- </para>
- </listitem>
- </itemizedlist>
- <para>
- Packet command mode uses the same RF frequencies as telemetry
- mode. Configure the desired TeleDongle frequency using the
- flight monitor window frequency 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>
- TeleMini listens for a command packet for five seconds after
- first being turned on, if it doesn't hear anything, it enters
- 'pad' mode, ready for flight and will no longer listen for
- command packets.
- </para>
- <para>
- When packet command mode is enabled, you can monitor the link
- by watching the lights on the
- devices. The red LED will flash each time they
- transmit a packet while the green LED will light up
- on TeleDongle while it is waiting to receive a packet from
- the altimeter.
- </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 frequency being monitored by the TeleDongle device is
- displayed at the top of the window. You can configure the
- frequecy by clicking on the frequency box and selecting the desired
- frequency. AltosUI remembers the last frequency selected for each
- TeleDongle and selects that automatically the next time you use
- that device.
- </para>
- <para>
- Below the TeleDongle frequency selector, the window contains a few
- significant pieces of information about the altimeter providing
- the telemetry data stream:
- </para>
- <itemizedlist>
- <listitem>
- <para>The configured callsign</para>
- </listitem>
- <listitem>
- <para>The device serial number</para>
- </listitem>
- <listitem>
- <para>The flight number. Each altimeter 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>
+ </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.
+ other tabs at any time. The final 'table' tab displays all of
+ the raw telemetry values in one place in a spreadsheet-like format.
</para>
<section>
<title>Launch Pad</title>
<itemizedlist>
<listitem>
<para>
- Battery Voltage. This indicates whether the LiPo battery
+ Battery Voltage. This indicates whether the Li-Po 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
+ to the Li-Po battery voltage. A value greater than 3.2V is
required for a 'GO' status.
</para>
</listitem>
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
+ to the Li-Po battery voltage. A value greater than 3.2V is
required for a 'GO' status.
</para>
</listitem>
+ <listitem>
+ <para>
+ On-board Data Logging. This indicates whether there is
+ space remaining on-board to store flight data for the
+ upcoming flight. If you've downloaded data, but failed
+ to erase flights, there may not be any space
+ left. TeleMetrum can store multiple flights, depending
+ on the configured maximum flight log size. TeleMini
+ stores only a single flight, so it will need to be
+ downloaded and erased after each flight to capture
+ data. This only affects on-board flight logging; the
+ altimeter will still transmit telemetry and fire
+ ejection charges at the proper times.
+ </para>
+ </listitem>
<listitem>
<para>
GPS Locked. For a TeleMetrum device, this indicates whether the GPS receiver is
</listitem>
</itemizedlist>
<para>
- The LaunchPad tab also shows the computed launch pad position
+ 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>
<para>
The height, speed and acceleration are shown along with the
- maxium values for each of them. This allows you to quickly
+ maximum values for each of them. This allows you to quickly
answer the most commonly asked questions you'll hear during
flight.
</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.
+ height. Good descent rates vary based on the choice of recovery
+ components, but generally range from 15-30m/s on drogue and should
+ be below 10m/s when under the main parachute in a dual-deploy flight.
</para>
<para>
For TeleMetrum altimeters, you can locate the rocket in the sky
<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.
+ the status of the apogee charge is. Note that some commercial
+ e-matches are designed to retain continuity even after being
+ fired, and will continue to show as green or return from red to
+ green after firing.
</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
+ recovery. While the radio signal is often 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>
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
+ whether to walk or hitch a ride. Take the reported
+ latitude and longitude and enter them into your hand-held GPS
unit and have that compute a track to the landing location.
</para>
<para>
Both TeleMini and TeleMetrum will continue to transmit RDF
tones after landing, allowing you to locate the rocket by
- following the radio signal. You may need to get away from
- the clutter of the flight line, or even get up on a hill (or
- your neighbor's RV) to receive the RDF signal.
+ following the radio signal if necessary. You may need to get
+ away from the clutter of the flight line, or even get up on
+ a hill (or your neighbor's RV roof) to receive the RDF signal.
</para>
<para>
- Finally, the maximum height, speed and acceleration reported
+ The maximum height, speed and acceleration reported
during the flight are displayed for your admiring observers.
+ The accuracy of these immediate values depends on the quality
+ of your radio link and how many packets were received.
+ Recovering the on-board data after flight will likely yield
+ more precise results.
</para>
+ <para>
+ To get more detailed information about the flight, you can
+ click on the 'Graph Flight' button which will bring up a
+ graph window for the current flight.
+ </para>
</section>
<section>
<title>Site Map</title>
<para>
- When the TeleMetrum gets a GPS fix, the Site Map tab will map
+ When the TeleMetrum has 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
+ rocket's state is indicated by color: 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.
+ to keep the rocket roughly centered 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
+ and cached on disk for reuse. If map images cannot be downloaded,
+ the rocket's path will be traced on a dark gray background
instead.
</para>
<para>
<title>Save Flight Data</title>
<para>
The altimeter records flight data to its internal flash memory.
- The TeleMetrum data is recorded at a much higher rate than the telemetry
+ TeleMetrum 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
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 or TeleMini device connected via the
- packet command link to the specified TeleDongle. See the chapter
- on Packet Command Mode for more information about this.
+ will be downloaded from an altimeter over radio link via the
+ specified TeleDongle. See the chapter on Controlling An Altimeter
+ Over The Radio Link for more information.
</para>
<para>
After the device has been selected, a dialog showing the
select which flights to download and which to delete. With
version 0.9 or newer firmware, you must erase flights in order
for the space they consume to be reused by another
- flight. This prevents you from accidentally losing flight data
+ flight. This prevents accidentally losing flight data
if you neglect to download data before flying again. Note that
if there is no more space available in the device, then no
- data will be recorded for a flight.
+ data will be recorded during the next flight.
</para>
<para>
- The filename for each flight log is computed automatically
+ The file name for each flight log is computed automatically
from the recorded flight date, altimeter serial number and
flight number information.
</para>
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.
+ Once a flight record is selected, a window with two tabs is
+ opened. The first tab contains a graph with acceleration
+ (blue), velocity (green) and altitude (red) of the flight,
+ measured in metric units. The
+ apogee(yellow) and main(magenta) igniter voltages are also
+ displayed; high voltages indicate continuity, low voltages
+ indicate open circuits. The second tab contains some basic
+ flight statistics.
</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
+ The right mouse button causes a pop-up 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.
- Use saved flight data for graphing where possible.
+ Use saved flight data in .eeprom files 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
+ 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
configuration information from the altimeter, 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.
+ many tools can be configured to skip over.
</para>
<para>
The remaining lines of the file contain the data, with each
<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.
+ This is the format used by Google Earth to provide an overlay
+ within that application. With this, you can use Google Earth to
+ see the whole flight path in 3D.
</para>
</section>
</section>
<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 a remote
- altimeter. Learn how to use this in the Packet Command
- Mode chapter.
+ device will use the radio link to configure a remote altimeter.
</para>
<para>
The first few lines of the dialog provide information about the
<para>
Reboot. This reboots the device. Use this to
switch from idle to pad mode by rebooting once the rocket is
- oriented for flight.
+ oriented for flight, or to confirm changes you think you saved
+ are really saved.
</para>
</listitem>
<listitem>
<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
+ the same time, as that can over pressurize the apogee deployment
+ bay and cause a structural failure of the air-frame. The Apogee
Delay parameter tells the flight computer to fire the apogee
charge a certain number of seconds after apogee has been
detected.
<para>
The radios in every Altus Metrum device are calibrated at the
factory to ensure that they transmit and receive on the
- specified frequency. You can adjust that
- calibration by changing this value. To change the TeleDongle's
- calibration, you must reprogram the unit completely.
+ specified frequency. If you need to you can adjust the calibration
+ by changing this value. Do not do this without understanding what
+ the value means, read the appendix on calibration and/or the source
+ code for more information. To change a 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
+ This sets the call sign included in each telemetry packet. Set this
as needed to conform to your local radio regulations.
</para>
</section>
size. A smaller value will allow more flights to be stored,
a larger value will record data from longer flights.
</para>
+ </section>
+ <section>
+ <title>Ignite Mode</title>
<para>
- During ascent, TeleMetrum records barometer and
- accelerometer values 100 times per second, other analog
- information (voltages and temperature) 6 times per second
- and GPS data once per second. During descent, the non-GPS
- data is recorded 1/10th as often. Each barometer +
- accelerometer record takes 8 bytes.
- </para>
- <para>
- The default, 192kB, will store over 200 seconds of data at
- the ascent rate, or over 2000 seconds of data at the descent
- rate. That's plenty for most flights. This leaves enough
- storage for five flights in a 1MB system, or 10 flights in a
- 2MB system.
+ TeleMetrum and TeleMini provide two igniter channels as they
+ were originally designed as dual-deploy flight
+ computers. This configuration parameter allows the two
+ channels to be used in different configurations.
</para>
+ <itemizedlist>
+ <listitem>
+ <para>
+ Dual Deploy. This is the usual mode of operation; the
+ 'apogee' channel is fired at apogee and the 'main'
+ channel at the height above ground specified by the
+ 'Main Deploy Altitude' during descent.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Redundant Apogee. This fires both channels at
+ apogee, the 'apogee' channel first followed after a two second
+ delay by the 'main' channel.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Redundant Main. This fires both channels at the
+ height above ground specified by the Main Deploy
+ Altitude setting during descent. The 'apogee'
+ channel is fired first, followed after a two second
+ delay by the 'main' channel.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </section>
+ <section>
+ <title>Pad Orientation</title>
<para>
- The configuration block takes the last available block of
- memory, on v1.0 boards that's just 256 bytes. However, the
- flash part on the v1.1 boards uses 64kB for each block.
- </para>
- <para>
- TeleMini has 5kB of on-board storage, which is plenty for a
- single flight. Make sure you download and delete the data
- before a subsequent flight or it will not log any data.
+ Because it includes an accelerometer, TeleMetrum is
+ sensitive to the orientation of the board. By default, it
+ expects the antenna end to point forward. This parameter
+ allows that default to be changed, permitting the board to
+ be mounted with the antenna pointing aft instead.
</para>
+ <itemizedlist>
+ <listitem>
+ <para>
+ Antenna Up. In this mode, the antenna end of the
+ TeleMetrum board must point forward, in line with the
+ expected flight path.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Antenna Down. In this mode, the antenna end of the
+ TeleMetrum board must point aft, in line with the
+ expected flight path.
+ </para>
+ </listitem>
+ </itemizedlist>
</section>
</section>
<section>
<section>
<title>Voice Settings</title>
<para>
- AltosUI provides voice annoucements during flight so that you
+ AltosUI provides voice announcements 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.
<listitem>
<para>
Test Voice—Plays a short message allowing you to verify
- that the audio systme is working and the volume settings
+ that the audio system is working and the volume settings
are reasonable
</para>
</listitem>
<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
+ This value is transmitted in each command packet sent from
+ TeleDongle and received from an altimeter. It is not used in
+ telemetry mode, as the callsign configured in the altimeter board
+ is included in all telemetry packets. Configure this
+ with the AltosUI operators call sign as needed to comply with
your local radio regulations.
</para>
</section>
+ <section>
+ <title>Font Size</title>
+ <para>
+ Selects the set of fonts used in the flight monitor
+ window. Choose between the small, medium and large sets.
+ </para>
+ </section>
<section>
<title>Serial Debug</title>
<para>
<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.
+ This reprograms any Altus Metrum device by using a TeleMetrum
+ or TeleDongle as a programming dongle. Please read the
+ directions for flashing devices in the Updating Device
+ Firmware chapter below.
</para>
<para>
Once you have the programmer and target devices connected,
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.
+ to snake wires inside the air-frame.
</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.
+ continuity test status for both apogee and main charges.
</para>
<para>
Next, select the desired igniter to fire. This will enable the
<para>
In the rocket itself, you just need a <ulink url="http://www.altusmetrum.org/TeleMetrum/">TeleMetrum</ulink> or
<ulink url="http://www.altusmetrum.org/TeleMini/">TeleMini</ulink> board and
- a LiPo rechargeable battery. An 860mAh battery weighs less than a 9V
+ a Li-Po rechargeable battery. An 860mAh battery weighs less than a 9V
alkaline battery, and will run a TeleMetrum for hours.
A 110mAh battery weighs less than a triple A battery and will run a TeleMetrum for
a few hours, or a TeleMini for much (much) longer.
</para>
<para>
By default, we ship the altimeters with a simple wire antenna. If your
- electronics bay or the airframe it resides within is made of carbon fiber,
+ electronics bay or the air-frame 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.
<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
+ feed
-line 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.
+ 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 radio link to extract the more detailed data
+ logged in either TeleMetrum or TeleMini devices, 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 Li-Po
+ 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 TeleMetrum-equipped rocket lands out of sight, you may enjoy having a hand-held GPS
+ receiver, so that you can put in a way-point for the last reported rocket
+ position before touch-down. This makes looking for your rocket a lot like
+ Geo-Caching... just go to the way-point 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 feed-line
+ </listitem>
+ <listitem>
+ a TeleDongle
+ </listitem>
+ <listitem>
+ a notebook computer
+ </listitem>
+ <listitem>
+ optionally, a hand-held 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- or TeleMini- 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 during the flight itself, and the more
+ complete data log recorded in the flash memory on the altimeter
+ board. Once this data is on your computer, our post-flight 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 TeleMetrum data file
+ usable 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.
+ </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>
+ </chapter>
+ <chapter>
+ <title>Altimeter Installation Recommendations</title>
+ <para>
+ Building high-power rockets that fly safely is hard enough. Mix
+ in some sophisticated electronics and a bunch of radio energy
+ and oftentimes you find few perfect solutions. This chapter
+ contains some suggestions about how to install Altus Metrum
+ products into the rocket air-frame, including how to safely and
+ reliably mix a variety of electronics into the same air-frame.
+ </para>
+ <section>
+ <title>Mounting the Altimeter</title>
+ <para>
+ The first consideration is to ensure that the altimeter is
+ securely fastened to the air-frame. For TeleMetrum, we use
+ nylon standoffs and nylon screws; they're good to at least 50G
+ and cannot cause any electrical issues on the board. For
+ TeleMini, we usually cut small pieces of 1/16" balsa to fit
+ under the screw holes, and then take 2x56 nylon screws and
+ screw them through the TeleMini mounting holes, through the
+ balsa and into the underlying material.
+ </para>
+ <orderedlist inheritnum='inherit' numeration='arabic'>
+ <listitem>
+ Make sure TeleMetrum is aligned precisely along the axis of
+ acceleration so that the accelerometer can accurately
+ capture data during the flight.
+ </listitem>
+ <listitem>
+ Watch for any metal touching components on the
+ board. Shorting out connections on the bottom of the board
+ can cause the altimeter to fail during flight.
+ </listitem>
+ </orderedlist>
+ </section>
+ <section>
+ <title>Dealing with the Antenna</title>
+ <para>
+ The antenna supplied is just a piece of solid, insulated,
+ wire. If it gets damaged or broken, it can be easily
+ replaced. It should be kept straight and not cut; bending or
+ cutting it will change the resonant frequency and/or
+ impedance, making it a less efficient radiator and thus
+ reducing the range of the telemetry signal.
+ </para>
+ <para>
+ Keeping metal away from the antenna will provide better range
+ and a more even radiation pattern. In most rockets, it's not
+ entirely possible to isolate the antenna from metal
+ components; there are often bolts, all-thread and wires from other
+ electronics to contend with. Just be aware that the more stuff
+ like this around the antenna, the lower the range.
+ </para>
+ <para>
+ Make sure the antenna is not inside a tube made or covered
+ with conducting material. Carbon fiber is the most common
+ culprit here -- CF is a good conductor and will effectively
+ shield the antenna, dramatically reducing signal strength and
+ range. Metallic flake paint is another effective shielding
+ material which is to be avoided around any antennas.
+ </para>
+ <para>
+ If the ebay is large enough, it can be convenient to simply
+ mount the altimeter at one end and stretch the antenna out
+ inside. Taping the antenna to the sled can keep it straight
+ under acceleration. If there are metal rods, keep the
+ antenna as far away as possible.
+ </para>
+ <para>
+ For a shorter ebay, it's quite practical to have the antenna
+ run through a bulkhead and into an adjacent bay. Drill a small
+ hole in the bulkhead, pass the antenna wire through it and
+ then seal it up with glue or clay. We've also used acrylic
+ tubing to create a cavity for the antenna wire. This works a
+ bit better in that the antenna is known to stay straight and
+ not get folded by recovery components in the bay. Angle the
+ tubing towards the side wall of the rocket and it ends up
+ consuming very little space.
+ </para>
+ <para>
+ If you need to place the antenna at a distance from the
+ altimeter, you can replace the antenna with an edge-mounted
+ SMA connector, and then run 50Ω coax from the board to the
+ antenna. Building a remote antenna is beyond the scope of this
+ manual.
+ </para>
+ </section>
+ <section>
+ <title>Preserving GPS Reception</title>
+ <para>
+ The GPS antenna and receiver in TeleMetrum are highly
+ sensitive and normally have no trouble tracking enough
+ satellites to provide accurate position information for
+ recovering the rocket. However, there are many ways to
+ attenuate the GPS signal.
+ <orderedlist inheritnum='inherit' numeration='arabic'>
+ <listitem>
+ Conductive tubing or coatings. Carbon fiber and metal
+ tubing, or metallic paint will all dramatically attenuate the
+ GPS signal. We've never heard of anyone successfully
+ receiving GPS from inside these materials.
+ </listitem>
+ <listitem>
+ Metal components near the GPS patch antenna. These will
+ de-tune the patch antenna, changing the resonant frequency
+ away from the L1 carrier and reduce the effectiveness of the
+ antenna. You can place as much stuff as you like beneath the
+ antenna as that's covered with a ground plane. But, keep
+ wires and metal out from above the patch antenna.
+ </listitem>
+ </orderedlist>
+ </para>
+ </section>
+ <section>
+ <title>Radio Frequency Interference</title>
+ <para>
+ Any altimeter will generate RFI; the digital circuits use
+ high-frequency clocks that spray radio interference across a
+ wide band. Altus Metrum altimeters generate intentional radio
+ signals as well, increasing the amount of RF energy around the board.
+ </para>
+ <para>
+ Rocketry altimeters also use precise sensors measuring air
+ pressure and acceleration. Tiny changes in voltage can cause
+ these sensor readings to vary by a huge amount. When the
+ sensors start mis-reporting data, the altimeter can either
+ fire the igniters at the wrong time, or not fire them at all.
+ </para>
+ <para>
+ Voltages are induced when radio frequency energy is
+ transmitted from one circuit to another. Here are things that
+ influence the induced voltage and current:
+ </para>
+ <itemizedlist>
+ <listitem>
+ Keep wires from different circuits apart. Moving circuits
+ further apart will reduce RFI.
+ </listitem>
+ <listitem>
+ Avoid parallel wires from different circuits. The longer two
+ wires run parallel to one another, the larger the amount of
+ transferred energy. Cross wires at right angles to reduce
+ RFI.
+ </listitem>
+ <listitem>
+ Twist wires from the same circuits. Two wires the same
+ distance from the transmitter will get the same amount of
+ induced energy which will then cancel out. Any time you have
+ a wire pair running together, twist the pair together to
+ even out distances and reduce RFI. For altimeters, this
+ includes battery leads, switch hookups and igniter
+ circuits.
+ </listitem>
+ <listitem>
+ Avoid resonant lengths. Know what frequencies are present
+ in the environment and avoid having wire lengths near a
+ natural resonant length. Altusmetrum products transmit on the
+ 70cm amateur band, so you should avoid lengths that are a
+ simple ratio of that length; essentially any multiple of 1/4
+ of the wavelength (17.5cm).
+ </listitem>
+ </itemizedlist>
+ </section>
+ <section>
+ <title>The Barometric Sensor</title>
+ <para>
+ Altusmetrum altimeters measure altitude with a barometric
+ sensor, essentially measuring the amount of air above the
+ rocket to figure out how high it is. A large number of
+ measurements are taken as the altimeter initializes itself to
+ figure out the pad altitude. Subsequent measurements are then
+ used to compute the height above the pad.
+ </para>
+ <para>
+ To accurately measure atmospheric pressure, the ebay
+ containing the altimeter must be vented outside the
+ air-frame. The vent must be placed in a region of linear
+ airflow, have smooth edges, and away from areas of increasing or
+ decreasing pressure.
+ </para>
+ <para>
+ The barometric sensor in the altimeter is quite sensitive to
+ chemical damage from the products of APCP or BP combustion, so
+ make sure the ebay is carefully sealed from any compartment
+ which contains ejection charges or motors.
+ </para>
+ </section>
+ <section>
+ <title>Ground Testing</title>
+ <para>
+ The most important aspect of any installation is careful
+ ground testing. Bringing an air-frame up to the LCO table which
+ hasn't been ground tested can lead to delays or ejection
+ charges firing on the pad, or, even worse, a recovery system
+ failure.
+ </para>
+ <para>
+ Do a 'full systems' test that includes wiring up all igniters
+ without any BP and turning on all of the electronics in flight
+ mode. This will catch any mistakes in wiring and any residual
+ RFI issues that might accidentally fire igniters at the wrong
+ time. Let the air-frame sit for several minutes, checking for
+ adequate telemetry signal strength and GPS lock. If any igniters
+ fire unexpectedly, find and resolve the issue before loading any
+ BP charges!
+ </para>
+ <para>
+ Ground test the ejection charges. Prepare the rocket for
+ flight, loading ejection charges and igniters. Completely
+ assemble the air-frame and then use the 'Fire Igniters'
+ interface through a TeleDongle to command each charge to
+ fire. Make sure the charge is sufficient to robustly separate
+ the air-frame and deploy the recovery system.
+ </para>
+ </section>
+ </chapter>
+ <chapter>
+ <title>Updating Device Firmware</title>
+ <para>
+ The big concept to understand is that you have to use a
+ TeleDongle as a programmer to update a TeleMetrum or TeleMini,
+ and a TeleMetrum or other TeleDongle to program the TeleDongle
+ Due to limited memory resources in the cc1111, we don't support
+ programming 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 the altimeter 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-v1.1-1.0.0.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 TeleMini Firmware</title>
+ <orderedlist inheritnum='inherit' numeration='arabic'>
+ <listitem>
+ You'll need a special 'programming cable' to reprogram the
+ TeleMini. It's available on the Altus Metrum web store, or
+ you can make your own using an 8-pin MicroMaTch connector on
+ one end and a set of four pins on the other.
+ </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-pins into the holes
+ in the TeleMini circuit board. Note that the MicroMaTch
+ connector has an alignment pin that goes through a hole in
+ the PC board when you have the cable oriented correctly, and
+ that pin 1 on the TeleMini board is marked with a square pad
+ while the other pins have round pads.
+ </listitem>
+ <listitem>
+ Attach a battery to the TeleMini board.
+ </listitem>
+ <listitem>
+ Plug the TeleDongle into your computer's USB port, and power
+ up the TeleMini
+ </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 TeleMini, which should have a
+ name in the form telemini-v1.0-1.0.0.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 TeleMini with new firmware, showing a progress bar.
+ </listitem>
+ <listitem>
+ Confirm that the TeleMini board seems to have updated OK, which you
+ can do by configuring it over the radio link through the TeleDongle, or
+ letting it come up in "flight" mode and listening for telemetry.
+ </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 or TeleMini
+ firmware, but you use either a TeleMetrum or another TeleDongle as the programmer.
+ </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 or TeleDongle.
+ </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 programmer, 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 if you're using one.
+ </listitem>
+ <listitem>
+ Plug both the programmer and the TeleDongle into your computer's USB
+ ports, and power up the programmer.
+ </listitem>
+ <listitem>
+ Run AltosUI, and select 'Flash Image' from the File menu.
+ </listitem>
+ <listitem>
+ Pick the programmer 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-v0.2-1.0.0.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>
+ </chapter>
+ <chapter>
+ <title>Hardware Specifications</title>
+ <section>
+ <title>TeleMetrum 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 down-link.
+ </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 Li-Po rechargeable batteries.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Uses Li-Po to fire e-matches, can be modified to support
+ optional separate pyro battery if needed.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ 2.75 x 1 inch board designed to fit inside 29mm air-frame coupler tube.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </section>
+ <section>
+ <title>TeleMini 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 down-link.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Barometric pressure sensor good to 45k feet MSL.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ On-board 5 kilobyte non-volatile memory for flight data storage.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ RF interface for battery charging, configuration, and data recovery.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Support for Li-Po rechargeable batteries, using an external charger.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Uses Li-Po to fire e-matches, can be modified to support
+ optional separate pyro battery if needed.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ 1.5 x .5 inch board designed to fit inside 18mm air-frame coupler tube.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </section>
+ </chapter>
+ <chapter>
+ <title>FAQ</title>
+ <para>
+ 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) 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 or lights like the manual mentions?
+ That's the "pad" mode. Weak batteries might be the problem.
+ It is also possible that the TeleMetrum is horizontal and the output
+ is instead a "dit-dit" meaning 'idle'. For TeleMini, it's possible that
+ it received a command packet which would have left it in "pad" mode.
+ </para>
+ <para>
+ How do I save flight data?
+ Live telemetry is written to file(s) whenever AltosUI is connected
+ to the TeleDongle. The file area defaults to ~/TeleMetrum
+ but is easily changed using the menus in AltosUI. The files that
+ are written end in '.telem'. The after-flight
+ data-dumped files will end in .eeprom and represent continuous data
+ unlike the .telem files that are subject to losses
+ along the RF data path.
+ See the above instructions on what and how to save the eeprom stored
+ data after physically retrieving your altimeter. Make sure to save
+ the on-board data after each flight; while the TeleMetrum can store
+ multiple flights, you never know when you'll lose the altimeter...
+ </para>
+ </chapter>
+ <appendix>
+ <title>Notes for Older Software</title>
+ <para>
+ <emphasis>
+ Before AltosUI was written, using Altus Metrum devices required
+ some finesse with the Linux command line. There was a limited
+ GUI tool, ao-view, which provided functionality similar to the
+ Monitor Flight window in AltosUI, but everything else was a
+ fairly 80's experience. This appendix includes documentation for
+ using that software.
+ </emphasis>
+ </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>
+ TeleMini can be communicated with through a TeleDongle device
+ over the radio link. When first booted, TeleMini listens for a
+ TeleDongle device and if it receives a packet, it goes into
+ 'idle' mode. Otherwise, it goes into 'pad' mode and waits to be
+ launched. The easiest way to get it talking is to start the
+ communication link on the TeleDongle and the power up the
+ TeleMini board.
+ </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>
+ All of the Altus Metrum devices 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 Flash memory; TeleDongle doesn't provide any storage
+ for these options and so they'll all be lost when you unplug it.
+ </para>
+ <para>
+ Try setting these configuration ('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>
+ To set the radio frequency, use the 'c R' command to specify the
+ radio transceiver configuration parameter. This parameter is computed
+ using the desired frequency, 'F', the radio calibration parameter, 'C' (showed by the 'c s' command) and
+ the standard calibration reference frequency, 'S', (normally 434.550MHz):
+ <programlisting>
+ R = F / S * C
+ </programlisting>
+ Round the result to the nearest integer value.
+ As with all 'c' sub-commands, follow this with a 'c w' to write the
+ change to the parameter block in the on-board flash on
+ your altimeter board if you want the change to stay in place across reboots.
</para>
<para>
- After the flight, you can use the RF link to extract the more detailed data
- logged in either TeleMetrum or TeleMini devices, 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.
+ 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>
- If your TeleMetrum-equiped 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.
+ 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>
<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.
+ To calibrate the radio frequency, connect the UHF antenna port to a
+ frequency counter, set the board to 434.550MHz, 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>
+ <para>
+ Note that the 'reboot' command, which is very useful on the altimeters,
+ 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 radio link access
+ between an altimeter and 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 altimeters
+ can be placed in. TeleMetrum uses the position of the device when booting
+ up will determine whether the unit is in "pad" or "idle" mode. TeleMini
+ enters "idle" mode when it receives a command packet within the first 5 seconds
+ of being powered up, otherwise it enters "pad" mode.
+ </para>
+ <para>
+ You can access an altimeter in idle mode from the TeleDongle's USB
+ connection using the radio link
+ by issuing a 'p' command to the TeleDongle. Practice connecting and
+ disconnecting ('~~' while using 'cu') from the altimeter. 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 radio link allows you to configure the altimeter, 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 altimeter 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>
+ 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>
+ <para>
+ On TeleMetrum, the GPS will eventually find enough satellites, lock in on them,
+ and 'ao-view' will both auditorily 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>
+ The altimeters provide RDF (radio direction finding) tones on
+ the pad, during descent and after landing. These can be used to
+ locate the rocket using a directional antenna; the signal
+ strength providing an indication of the direction from receiver to rocket.
+ </para>
+ <para>
+ TeleMetrum also provides GPS tracking data, which can further simplify
+ 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>
+ </appendix>
+ <appendix>
+ <title>Calibration</title>
+ <para>
+ There are only two calibrations required for a TeleMetrum board, and
+ only one for TeleDongle and TeleMini. All boards are shipped from
+ the factory pre-calibrated, but the procedures are documented here
+ in case they are ever needed. Re-calibration is not supported by
+ AltosUI, you must connect to the board with a serial terminal program
+ and interact directly with the on-board command interpreter to effect
+ calibration.
+ </para>
+ <section>
+ <title>Radio Frequency</title>
<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>
+ 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>
- 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- or TeleMini- equipped rocket when used with a suitable 70cm HT.
+ To calibrate the radio frequency, connect the UHF antenna port to a
+ frequency counter, set the board to 434.550MHz, and use the 'C'
+ command in the on-board command interpreter to generate a CW
+ carrier. For TeleMetrum, this is best done over USB. For TeleMini,
+ note that the only way to escape the 'C' command is via power cycle
+ since the board will no longer be listening for commands once it
+ starts generating a CW carrier.
+ </para>
+ <para>
+ 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>
+ <para>
+ Note that any time you re-do the radio frequency calibration, the
+ radio frequency is reset to the default 434.550 Mhz. If you want
+ to use another frequency, you will have to set that again after
+ calibration is completed.
+ </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 flash memory on the altimeter
- 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 TeleMetrum data file
- useable with Google Maps and Google Earth for visualizing the flight path
- in two or three dimensions!
- </para>
+ <title>TeleMetrum Accelerometer</title>
<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.
+ The TeleMetrum 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 ratio-metric to
+ the ADC converter, and calibration is required. Explicitly
+ calibrating the accelerometers also allows us to load any device
+ 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>
- </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.
+ 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. Note that the accuracy of this
+ calibration depends primarily on how perfectly vertical and still
+ the board is held during the cal process. 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>
- 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.
+ The +1g and -1g calibration points are included in each telemetry
+ frame and are part of the header stored in onboard flash to be
+ downloaded after flight. We always store and return raw ADC
+ samples for each sensor... so nothing is permanently "lost" or
+ "damaged" if the calibration is poor.
</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...
+ In the unlikely event an accel cal 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 link. 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),
+ allowing a re-cal.
</para>
- </section>
- </chapter>
+ </section>
+ </appendix>
+ <appendix
+ xmlns:xi="http://www.w3.org/2001/XInclude">
+ <title>Release Notes</title>
+ <xi:include href="release-notes-1.0.xsl" xpointer="xpointer(/article/*)"/>
+ <xi:include href="release-notes-0.9.2.xsl" xpointer="xpointer(/article/*)"/>
+ <xi:include href="release-notes-0.9.xsl" xpointer="xpointer(/article/*)"/>
+ <xi:include href="release-notes-0.8.xsl" xpointer="xpointer(/article/*)"/>
+ <xi:include href="release-notes-0.7.1.xsl" xpointer="xpointer(/article/*)"/>
+ </appendix>
</book>
+
+<!-- LocalWords: Altusmetrum
+-->
projects / fw / altos / blobdiff