I don’t really understand the firmware (yet), but I wonder if the pixhawk runs a calibration routine at each power-up.
I mean the IMU data precision also depends on the acutal position (magnetometer) and temperature. So it might make sense to run a calibration after each time the battery gets connected to the pixhawk.
The calibration code is in the commander module and only runs when requested (doesn’t run each startup).
There was some work done on IMU temperature compensation, but it was never completed. This would be much better than an automatic/forced calibration every startup. https://github.com/PX4/Firmware/tree/tempcal_rebase
