EKF3 IMU2 switching compass 0/1


We made a quadcopter and have been flying for a while. I use two here3 GPS units. I only enable compasses from these GPS units for flights. Both compasses have been calibrated and gave green status indicating the calibration is successfull.

  1. However I see “EKF3 IMU2 switching to compass 1” and “EKF3 IMU2 switching to compass 0” in the logs. Do I need to be worried about this message? You can see this message in the image below. In one of the flights, this message was notified for every 10 seconds switching between compass 0 and compass 1.

  1. I also see, events saying EV : GPS Primary changed. Do I need to be worried about this message? You can see this event in the above screenshot.

  2. When I run Auto Analysis from mission planner, I get “Compass : Fail”. Even after calibration showing green status, this confused us.

Link to the log file is here : Link

Please suggest if there is a need to improve compass health. I know that the drone is currently flown with stock parameters. I usually tune the drone with HNTCH enabled. Any guidance is very much appreciated.

This will tell you nothing. Auto Analysis is far from up to date.
Use Magft to calibrate both compass’s and continue with Tuning.

Hello @dkemxr

Thank you for responding

I take it that you are suggesting that “I need to be worried about the messages and events” for my questions 1 and 2

Besides, I was inspecting my old logs and found this weird. This specific drone model did not have any issues in the beginning. In one of the flights, it should a message saying "internal error 1000000. And after landing I got a message saying “internal error 1000000 : 169 IMU_RESET”.

Post this flight, when we flew the drone again, switching compasses error started to appear

Link to log with internal errors : Link1
Link to log with switching compasses errors : Link2

Are these possibly related? Is it any way related to hardware issue? Should I consider replacing my cube orange?