[Paparazzi-devel] SD log with Apogee board

[Gautier Hattenberger]

Dear Paparazzi users,

Since last week, a new feature is available in the latest master for 
Apogee boards' users (https://wiki.paparazziuav.org/wiki/Apogee/v1.00). 
It allows to log data on the embedded SD card at high rate and without 
any additional boards.

In order to do this safely for the autopilot, we have used the real-time 
scheduler of ChibiOS with a thread for the current autopilot code and an 
other one for data logging. This is NOT a RTOS paparazzi version (which 
is under development in the paparazzi_rt branch, also using ChibiOS), 
but just the possibility to have a safe data logging.

The API is still pretty basic, and is likely to be improved in future 
paparazzi versions. It allows to manually write ascii data (same way as 
printf) or binary data (buffer+size or single byte). See 
sw/airborne/subsystems/chibios-libopencm3/sdLog.h file.

An example can be found in gps_ubx.c file where the raw GPS data are 
logged. The application for this was to perform trajectory 
post-processing using a LEA6-T module and RTKLIB (which actually works, 
but required a very good quality antenna in order to achieve best results).

Cheers,

Gautier for Paparazzi/Enac team