We tried using an APM 2.5 as a flight data recorder in a Cessna 208B. It was built into a 3D printed box with own power supply and recording done on a mobile phone.
There is one problem though: When the aircraft is in a steady bank the APM HUD indicates horizontal attitude as the resultant g-load is downwards relative to the APM. The difference between APM indicated attitude and aircraft artificial horizon is shown below. (Aircraft AH indicates about 30deg LH bank in top right corner)
UPDATE: THE PROBLEM SEEMS TO BE THAT ARDUCOPTER CODE WAS LOADED AND IT WAS FLOWN AS DISARMED, INSTEAD OF USING ARDUPLANE - THANKS DEVELOPERS!
@ AndrewTridgell or other PX4FMU user
did anyone of you used the Pixhawk as a stand alone datalogger?
Pixhawk sounds like the easiest plan.
Another good reason to upgrade to Pixhawk. Thanks.
The simplest is to use a PX4 or Pixhawk, which logs to a microSD card. You should have enough space for weeks of logs.
Thanks Stephen, I'll look into that option. Sounds like quite a lot of hardware though that could start interfering with the compass in the box.
Can't I just write code to redirect the onboard logging to one of the spare serial ports where I connect up a serial data logger and then put a switch in at the telemetry serial port to able/disable telemetry when I want to?
What I don't like about this is that I don't necessarily want to change the code of each new version of arduplane coming out.
Why not put a BeagleBone Black in the box with the APM and connect it up using the USB cable. The BBB will power the APM via the USB connection so you would only have to power the BBB. BBBs are about $50 and work really well. Then on the BBB run MavProxy and set logging on.
If the BBB has a 16GB SDCard or bigger it should be able to record a pretty large amount of data.
It is pretty easy to setup. If you connect an ethernet to wireless card into the BBB Rj45 port you should be able to connect your tablet running DroidPlanner and get the HUD etc and make sure it is working.
The --out option sends the mavlink packets out to a device that is connected.
I have an working BBB image with MAVProxy working if you would like it.
You might want to give a test on DroidPlanner as it has a HUD with more information than AndroPilot.
Droneshare - http://www.droneshare.com/view/dr2e3y5
Interesting to see these other applications for the APM. I'll be sure that there is a reliable manual overide before I let the APM control the plane I'm in though!
We are still working on a good solution to record data of flights longer than 20min without the need for a mobile phone or laptop. The idea is to just use the phone or laptop initially to verify correct setup.
@Malek, I can't visualise csv or text logs. Did you fly with laptop in aircraft and have a .tlog file to put on droneshare?
APM was powered on during flight, so "home" is not on the ground.