Calibration issue with accel and compass on V3.3 and V3.3.1

ArduCopter Copter 3.3
1

Hi,
I have a big problem, hope someone can help.
When I updated my Pixhawk from V3.2.1 to V3.3+ I’m not able to calibrate Accel and Compass correctly.
Here is what’s happening:
On the first connection after updating to V3.3 or V3.3.1 the voice is reading seemingly random numbers for about 10 seconds.
When I do the Accel Calibration, the voice is saying, besides the normal “place vehicle nose down/up…”, it also says “Initialising APM” after every position change. ???
After finishing the Accel Calibration I get this error messages:

  • error pos vert variance
  • error compas variance
  • bad AHRS

Also the HUD is not level and is slowly drifting back and forth in all directions. The Calibrating Level option has no effect.
The Compass is also drifting after compass calibration.

I think its a firmware problem since I only have this problem on V3.3 and V3.3.1.
When I get back to V3.2.1 everything is fine and works perfectly.
I tried this on 2 different Pixhawks with the same results.

Please help !!

2

3.3.1 works different than 3.2.1 did as it’s using EKF to balance things out. Also they now output the serial number of the Pixhawk when the unit is powered up.

I have two Pixhawks and they both work just fine.

Calibration is required for both Accel’s and Compasses otherwise the EKF will try to fix the issue on it’s own which is what your seeing in the HUD.

Mike

3

So is there a way to fix this?
Could it be that the calibration parameters are not beeing saved to the pixhawk for some reason?
That would explain why Accel and Compass are drifting after calibration.