From 458f816ad23fd6784757b13b244057d4be64260e Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Wed, 24 Aug 2011 23:06:01 -0700 Subject: [PATCH] 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 --- doc/altusmetrum.xsl | 75 ++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 74 insertions(+), 1 deletion(-) diff --git a/doc/altusmetrum.xsl b/doc/altusmetrum.xsl index 1b1f76a4..c778b1e1 100644 --- a/doc/altusmetrum.xsl +++ b/doc/altusmetrum.xsl @@ -536,7 +536,7 @@ NAR #88757, TRA #12200 or radio link via TeleDongle.
- Radio Frequencies + Radio Frequency 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.
+
+ Maximum Flight Log + + 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. + + + 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. + + + 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. + + + 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. + + + 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. + +
+
+ Ignite Mode + + 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. + + + 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. + +
+
+ Pad Orientation + + 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. + +
Calibration -- 2.30.2