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| -rw-r--r-- | doc/altusmetrum.xsl | 111 |
1 files changed, 85 insertions, 26 deletions
diff --git a/doc/altusmetrum.xsl b/doc/altusmetrum.xsl index 66c2b339..5a60da7a 100644 --- a/doc/altusmetrum.xsl +++ b/doc/altusmetrum.xsl @@ -536,7 +536,7 @@ NAR #88757, TRA #12200 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 @@ -583,6 +583,90 @@ NAR #88757, TRA #12200 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 + (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> + 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>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> @@ -1093,31 +1177,6 @@ NAR #88757, TRA #12200 size. A smaller value will allow more flights to be stored, a larger value will record data from longer flights. </para> - <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 1MB systems, or 10 flights in 2MB - systems. - </para> - <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 subsequent flights, or TeleMini will not log any data. - </para> </section> <section> <title>Ignite Mode</title> |