<section>
<title>Maximum Flight Log</title>
<para>
- Each flight computer logs data at 100 samples per second
- during ascent and 10 samples per second during descent. Data
- are logged to an on-board flash memory part, which can be
- partitioned into several equal-sized blocks, one for each
- flight.
- </para>
- <table frame='all'>
- <title>Data Storage on Altus Metrum altimeters</title>
- <tgroup cols='4' align='center' colsep='1' rowsep='1'>
- <colspec align='center' colwidth='*' colname='Device'/>
- <colspec align='center' colwidth='*' colname='Bytes per sample'/>
- <colspec align='center' colwidth='*' colname='Total storage'/>
- <colspec align='center' colwidth='*' colname='Minutes of
- full-rate'/>
- <thead>
- <row>
- <entry align='center'>Device</entry>
- <entry align='center'>Bytes per Sample</entry>
- <entry align='center'>Total Storage</entry>
- <entry align='center'>Minutes at Full Rate</entry>
- </row>
- </thead>
- <tbody>
- <row>
- <entry>TeleMetrum v1.x</entry>
- <entry>8</entry>
- <entry>2MB</entry>
- <entry>40</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- <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>
- Configuration data is also stored in the flash memory on
- TeleMetrum v1.x, TeleMini and EasyMini. This consumes 64kB
- of flash space. This configuration space is not available
- for storing flight log data. TeleMetrum v2.0 and TeleMega
- store configuration data in a bit of eeprom available within
- the processor chip.
- </para>
- <para>
- To compute the amount of space needed for a single flight,
- you can multiply the expected ascent time (in seconds) by
- 100 times bytes-per-sample (8 for TeleMetrum v1.x, 16 for
- TeleMetrum v2.0 and 32 for TeleMega), 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/v1.2 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>
- 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.
+ Changing this value will set the maximum amount of flight
+ log storage that an individual flight will use. The
+ available storage is divided into as many flights of the
+ specified size as can fit in the available space. You can
+ download and erase individual flight logs. If you fill up
+ the available storage, future flights will not get logged
+ until you erase some of the stored ones.
</para>
</section>
<section>
<section>
<title>Pyro Channels</title>
<para>
- TeleMega
+ In addition to the usual Apogee and Main pyro channels,
+ TeleMega has four additional channels that can be configured
+ to activate when various flight conditions are
+ satisfied. You can select as many conditions as necessary;
+ all of them must be met in order to activate the
+ channel. The conditions available are:
</para>
+ <itemizedlist>
+ <listitem>
+ <para>
+ Acceleration away from the ground. Select a value, and
+ then choose whether acceleration should be above or
+ below that value. Acceleration is positive upwards, so
+ accelerating towards the ground would produce negative
+ numbers. Acceleration during descent is noisy and
+ inaccurate, so be careful when using it during these
+ phases of the flight.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Vertical speed. Select a value, and then choose whether
+ vertical speed should be above or below that
+ value. Speed is positive upwards, so moving towards the
+ ground would produce negative numbers. Speed during
+ descent is a bit noisy and so be careful when using it
+ during these phases of the flight.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Height. Select a value, and then choose whether the
+ height above the launch pad should be above or below
+ that value.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Orientation. TeleMega contains a 3-axis gyroscope and
+ accelerometer which is used to measure the current
+ angle. Note that this angle is not the change in angle
+ from the launch pad, but rather absolute relative to
+ gravity; the 3-axis accelerometer is used to compute the
+ angle of the rocket on the launch pad and initialize the
+ system. Because this value is computed by integrating
+ rate gyros, it gets progressively less accurate as the
+ flight goes on. It should have an accumulated error of
+ less than .2°/second (after 10 seconds of flight, the
+ error should be less than 2°).
+ </para>
+ <para>
+ The usual use of the orientation configuration is to
+ ensure that the rocket is traveling mostly upwards when
+ deciding whether to ignite air starts or additional
+ stages. For that, choose a reasonable maximum angle
+ (like 20°) and set the motor igniter to require an angle
+ of less than that value.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Flight Time. Time since boost was detected. Select a
+ value and choose whether to activate the pyro channel
+ before or after that amount of time.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Ascending. A simple test saying whether the rocket is
+ going up or not. This is exactly equivalent to testing
+ whether the speed is > 0.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Descending. A simple test saying whether the rocket is
+ going down or not. This is exactly equivalent to testing
+ whether the speed is < 0.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ After Motor. The flight software counts each time the
+ rocket starts accelerating (presumably due to a motor or
+ motors igniting). Use this value to count ignitions for
+ multi-staged or multi-airstart launches.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Delay. This value doesn't perform any checks, instead it
+ inserts a delay between the time when the other
+ parameters become true and when the pyro channel is
+ activated.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Flight State. The flight software tracks the flight
+ through a sequence of states:
+ <orderedlist>
+ <listitem>
+ <para>
+ Boost. The motor has lit and the rocket is
+ accelerating upwards.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Fast. The motor has burned out and the rocket is
+ descellerating, but it is going faster than 200m/s.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Coast. The rocket is still moving upwards and
+ decelerating, but the speed is less than 200m/s.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Drogue. The rocket has reached apogee and is heading
+ back down, but is above the configured Main
+ altitude.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Main. The rocket is still descending, and is blow
+ the Main altitude
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Landed. The rocket is no longer moving.
+ </para>
+ </listitem>
+ </orderedlist>
+ </para>
+ <para>
+ You can select a state to limit when the pyro channel
+ may activate; note that the check is based on when the
+ rocket transitions *into* the state, and so checking for
+ 'greater than Boost' means that the rocket is currently
+ in boost state.
+ </para>
+ <para>
+ When a motor burns out, the rocket enters either Fast or
+ Coast state (depending on how fast it is moving). If the
+ computer detects upwards acceleration again, it will
+ move back to Boost state.
+ </para>
+ </listitem>
+ </itemizedlist>
</section>
</section>
<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
+ interacting with the Altus Metrum product family. AltosUI can
+ monitor telemetry data, configure 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
<section>
<title>Pad Orientation</title>
<para>
- 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.
+ Because it includes an accelerometer, TeleMetrum and
+ TeleMega are 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>
projects / fw / altos / blobdiff