Problem with internal magnetic sensors PIXHAWK 3 PRO

[CediBosshard]

Firmware v1.7.3 & QGC v3.3.0
During test flights I noticed that the drone does not fly the route I specified, but always flies in any other direction. Several times I recalibrated all sensor systems with QGroundControl and still got the following warining: preflight failed mag sensors inconsistent

I have read the following forum posts:

• preflight failed mag sensors inconsistent preflight failed mag sensors inconsistent #8475
• Solo PREFLIGHT FAIL: MAG SENSORS INCONSISTENT Solo PREFLIGHT FAIL: MAG SENSORS INCONSISTENT #8305
• preflight failed : mag sensors inconsistent EEPROM erase fails permanently on one board #24
• Pixracer magnetometer preflight error Pixracer magnetometer preflight error #8098

After a few searches, I found the cause:
One internal magnetic sensor provided data that differed greatly from the other internal magnetic sensor and the magnetic sensor of the external GPS compass module. I created plots in all three axes using FlightPlot.

Internal magnetic sensor (sensor_mag_0 & sensor_mag_1):

• MPU-9250
• LIS3MDL

External magnetic sensor (sensor_mag_2):

• LIS3MDL

I can’t tell which sensor is exactly mag_0 and which is mag_1.

In the X-axis the magnetic sensor 1 has an offset, in the Y- & Z-axis it looks as if the signal is mirrored.

First tried to change the orientation of the sensor (CAL_MAG1_ROT), but after the QGC after the fifth time, set the value back to Internal mag, we left this.
As a result, I have deactivated the magnetic sensor in QGroundControl, which has a systematic deviation (CAL_MAG1_EN set to Disabled).

Since that moment, the drone has been flying exactly as planned!

My questions are this now:

• Where could the error come from with the wrong signal?
• How can you fix it yourself?

Thanks for your help!
Regards Cédi

[xdwgood]

Just personal advice：　you can set CAL_MAG2_ROT = Internal mag

[CediBosshard]

What is the point if I set CAL_MAG2_ROT = Internal?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

Closing as stale.