doc: Describe max flight log, ignite mode and pad orientation

These describe what these configuration parmaeters do, not how to set them.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/doc/altusmetrum.xsl b/doc/altusmetrum.xsl
index 1b1f76a4002073a8e2e88e5d49bf4744ef26a754..c778b1e1a43872843cd2eecdb2a5cabe16693e12 100644 (file)
--- a/doc/altusmetrum.xsl
+++ b/doc/altusmetrum.xsl
@@ -536,7 +536,7 @@ NAR #88757, TRA #12200
         or radio link via TeleDongle.
       </para>
       <section>
         or radio link via TeleDongle.
       </para>
       <section>

-        <title>Radio Frequencies</title>
+        <title>Radio Frequency</title>

         <para>
          Altus Metrum boards support radio frequencies in the 70cm
          band. By default, the configuration interface provides a
         <para>
          Altus Metrum boards support radio frequencies in the 70cm
          band. By default, the configuration interface provides a


@@ -583,6 +583,79 @@ NAR #88757, TRA #12200
           simultaneously.
         </para>
       </section>
           simultaneously.
         </para>
       </section>

+      <section>
+       <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, 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>
+      </section>
+      <section>
+       <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>
     <section>
       <title>Calibration</title>
     </section>
     <section>
       <title>Calibration</title>