Extended Mag Cal

Cyclops positioning may benefit from an extended magnetometer calibration if there are issues with the heading. Please use this guide to run the extended mag calibration.

Procedure

Step 1: Standard Compass Calibration

First, please calibrate the compass using the Mission Planner or QGC Compass Calibration tool. This will create a baseline compass calibration that our software will use for the extended calibration.

Ensure that the external compass you are using is configured as Compass 1.

Step 2: Compass Extrinsics

After standard calibration, reboot the flight controller as prompted. Then connect to the Cyclops device over Ethernet. Run the following 2 commands to get the compass extrinsics helper tool running, and then follow the prompts on the device.

source /opt/vns-sdk/venv/bin/activate
python3 /lib/vns-sdk/scripts/calibrate_compass_extrinsics.py

Follow the prompts to do 2 full rotations while connected, one with wings level, and one with nose down. This will produce 5 parameters to change on your UAV.

ArduPilot Parameter	Description
CUST_ROT_ENABLE	Enables custom rotations
COMPASS_ORIENT	Applies custom rotation values to Compass 1
CUST_ROT1_PITCH	Custom pitch value
CUST_ROT1_ROLL	Custom roll value
CUST_ROT1_YAW	Custom yaw value

Step 3: Final Compass Calibration

After setting these parameters, you can now do a final compass calibration using the Mission Planner or QGC Compass Calibration tool. This will use the compass extrinsics parameters we set to do a refined calibration based on the compass extrinsics.

Once the calibration is complete, please reboot the flight controller as prompted. The compass is now calibrated.