more text created during SFO->DEN flight

diff --git a/doc/telemetrum.xsl b/doc/telemetrum.xsl
index 70a7869318be95bf1b6726f6cb6b9e4aea5471b9..793347f9dc1e0dc0c8704b9fa17f751cbab7906a 100644 (file)
--- a/doc/telemetrum.xsl
+++ b/doc/telemetrum.xsl
@@ -222,6 +222,97 @@
   </chapter>
   <chapter>
     <title>Operation</title>
+    <section>
+      <title>Firmware Modes </title>
+<para>
+       The AltOS firmware build for TeleMetrum has two fundamental modes,
+       "idle" and "flight".  Which of these modes the firmware operates in
+       is determined by the orientation of the rocket (well, actually the
+       board, of course...) at the time power is switched on.  If the rocket
+       is "nose up", then TeleMetrum assumes it's on a rail or rod being
+       prepared for launch, so the firmware chooses flight mode.  However,
+       if the rocket is more or less horizontal, the firmware instead enters
+       idle mode.
+</para>
+<para>
+       In flight mode, TeleMetrum turns on the GPS system, engages the flight
+       state machine, goes into transmit-only mode on the RF link sending 
+       telemetry, and waits for launch to be detected.  Flight mode is
+       indicated by an audible "di-dah-dah-dit" on the beeper, followed by
+       beeps indicating the state of the pyrotechnic igniter continuity.
+       One beep indicates [FIXME] apogee continuity, two beeps indicate
+       main continuity, three beeps indicate both apogee and main continuity,
+       and one longer "brap" sound indicates no continuity.  For a dual
+       deploy flight, make sure you're getting three beeps before launching!
+       For apogee-only or motor eject flights, do what makes sense.
+</para>
+<para>
+       In idle mode, the normal flight state machine is disengaged, and thus
+       no ejection charges will fire.  TeleMetrum also listens on the RF
+       link when in idle mode for packet mode requests sent from TeleDongle.
+       Commands can thus be issues to a TeleMetrum in idle mode over either
+       USB or the RF link equivalently.
+       Idle mode is useful for configuring TeleMetrum, for extracting data 
+       from the on-board storage chip after flight, and for ground testing
+       pyro charges.
+</para>
+<para>
+       One "neat trick" of particular value when TeleMetrum is used with very
+       large airframes, is that you can power the board up while the rocket
+       is horizontal, such that it comes up in idle mode.  Then you can 
+       raise the airframe to launch position, use a TeleDongle to open
+       a packet connection, and issue a 'reset' command which will cause
+       TeleMetrum to reboot, realize it's now nose-up, and thus choose
+       flight mode.  This is much safer than standing on the top step of a
+       rickety step-ladder or hanging off the side of a launch tower with
+       a screw-driver trying to turn on your avionics before installing
+       igniters!
+</para>
+    </section>
+    <section>
+      <title>GPS </title>
+<para>
+       TeleMetrum includes a complete GPS receiver.  See a later section for
+       a brief explanation of how GPS works that will help you understand
+       the information in the telemetry stream.  The bottom line is that
+       the TeleMetrum GPS receiver needs to lock onto at least four 
+       satellites to obtain a solid 3 dimensional position fix and know 
+       what time it is!
+</para>
+<para>
+       TeleMetrum provides backup power to the GPS chip any time a LiPo
+       battery is connected.  This allows the receiver to "warm start" on
+       the launch rail much faster than if every power-on were a "cold start"
+       for the GPS receiver.  In typical operations, powering up TeleMetrum
+       on the flight line in idle mode while performing final airframe
+       preparation will be sufficient to allow the GPS receiver to cold
+       start and acquire lock.  Then the board can be powered down during
+       RSO review and installation on a launch rod or rail.  When the board
+       is turned back on, the GPS system should lock very quickly, typically
+       long before igniter installation and return to the flight line are
+       complete.
+</para>
+    </section>
+    <section>
+      <title>Ground Testing </title>
+       <para>
+       An important aspect of preparing a rocket using electronic deployment
+       for flight is ground testing the recovery system.  Thanks
+       to the bi-directional RF link central to the Altus Metrum system, 
+       this can be accomplished in a TeleMetrum-equipped rocket without as
+       much work as you may be accustomed to with other systems.  It can
+       even be fun!
+       </para>
+       <para>
+       Just prep the rocket for flight, then power up TeleMetrum while the
+       airframe is horizontal.  This will cause the firmware to go into 
+       "idle" mode, in which the normal flight state machine is disabled and
+       charges will not fire without manual command.  Then, establish an
+       RF packet connection from a TeleDongle-equipped computer using the 
+       P command from a safe distance.  You can now command TeleMetrum to
+       fire the apogee or main charges to complete your testing.
+       </para>
+    </section>
     <section>
       <title>Radio Link </title>
       <para>
@@ -397,6 +488,14 @@
         </para>
       </section>
     </section>
+    <section>
+       <title>
+       How GPS Works
+       </title>
+       <para>
+       Placeholder.
+       </para>
+    </section>
   </chapter>
 </book>