Compass calibration for Revo running ChiBios

I am calibrating in MP the internal compass built-in in the Revolution FC (arduplane V4.0.5) running ChiBios.

Calibration page attached.

Have several questions :–

  1. What should I select in the Select Device section ?
  2. From the Ardupilot forum, I realize that :-- compass 1 is EXTERNAL, compass 2 is INTERNAL.

So I should choose compass 2 in the Primary Compass option, since I don’t have external compass, and check the “Use this compass” box under Compass#2.

After pressing “Start” in the Onboard Mag calibration section, the green status bar only progress half way and stop, and never finish the calibration.

I also tried different combination of Select Device, Primary compass option, it either results in calibration not initiated, or stop half way.

What has gone worng? Please help.