Compasses not being detected correctly


I recently updated my Pixhawk firmware to the one in the videos (apparently I used the wrong one) and it appears my compasses are no longer being detected properly (both were before). I re-setup and calibrated everything else; but I get the message the compasses are not calibrated and when I go into HW ID I see only 1 compass on I2C. I try to calibrate the one compass and it gives me the beep that it completed it successfully and the message that its successful and to reboot the autopilot. When I reboot I still get the same message that the compass isn’t calibrated and the data screen says no GPS. Any suggestions on how I get both compasses to register? I thought my external compass before had a red light that I can see on the top; however, I no longer see it come on.


I too, was having issues with compasses, Pixhawk was very flaky, not holding calibration, not always seeing all compasses. Sometimes the internal, other times the external. Could not get it to calibrate properly or keep calibration once successful. This controller had been in a minor mishap, the machine tipped up on it’s side in the desert dirt of Arizona. Suspecting silver, gold and other trace metals in the soil got into the case and may have been causing some electrical pathway alterations inconsistent with proper operation. So, we dismantled it, scoped the entire board and indeed, under magnification we could see desert dust on the board. After a thorough cleaning it seems now to have recognized both compasses and was able to calibrate. It doesn’t beep anymore though.
Just a tidbit to keep in the back of your minds when / if you have very odd behavior from Pixhawk.


Thanks for this tidbit. Turns out my external compass wasn’t working at all and just needed replaced.