Template:PTX COMPASSCAL

Magnetometer Calibration

Magnetometer Calibration Guide

In order for your magnetometer to provide accurate heading information, it must be calibrated.

Follow this guide to complete the calibration process.

1. Open the Magnetometer example for your device, and click the Calibrate button. This will open the Compass Calibration tool.

2. If your device supports heating, we recommend checking the HeatingEnabled checkbox. Wait for the temperature reading to turn green:

If your Spatial does not support heating (neither of the above controls will be available), you can skip this step.

3. Next, decide if you're using 2-axis or 3-axis calibration:

● If the spatial is free to move in all directions, use 3-axis

● If the spatial is being kept mostly level (e.g. in a car), use 2-axis

4. You can leave the Local Field Strength at 1.0 for general use since magnitude doesn't affect heading. If you need more quantitative results, look up your local value.

5. Make sure your Phidget Spatial is firmly in the position you intend to calibrate it for, and begin by clicking the Start button.

Begin rotating the structure your Phidget is mounted to. Notice the red dots appearing on the graph.

6. Try to rotate it so that it fills out as much of the sphere (or circle in 2-axis mode) as possible. When you're finished, click Stop.

You should now see red and green spheres (or circles) in the graph. The red one is the raw measurements, and the green one is the calibrated measurements.

Newly calibrated data from the magnetometer will be indicated by a green line that matches the sphere. The green sphere should be more centered than the red one. If not, try repeating the calibration.

You're now done the calibration process! On most Phidget Spatials, the calibration will be stored in flash, so it stays calibrated to this environment even across power cycles.

8. If you need to repeat this exact calibration, you can save the values listed in the text box.

You can use these values in the setMagnetometerCorrectionParameters method. See our API Documentation for more details.

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