We have developed an iPad application using the ARCL (AR + CoreLocation) library to render Point of Interest (POI) annotations in both an AR view and a standard MapView. The application performs as expected on standard devices.
However, we have some iPad covered with strong magnet. This creates significant magnetic interference, resulting in a 90° to 180° heading offset, rendering the AR POI placement and MapView orientation unusable.
Technical Challenges & Constraints:
Hardware Lock: The magnetic cover is a mandatory business requirement and cannot be removed during field use.
Sensor Failure: The internal magnetometer cannot provide an accurate North reference due to the proximity of the cover’s magnets. While CoreLocation and CoreMotion use sensor fusion, the magnetometer remains the primary source for absolute heading.
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Alternative Orientation Tracking: Is there a documented method to bypass the magnetometer and derive device orientation using only the Gyroscope and Accelerometer (e.g., relative tracking) while still maintaining alignment with geographic coordinates in CoreLocation?
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Programmatic Offsets: Are there known APIs or mathematical workarounds to programmatically "nullify" or offset a constant magnetic bias once the device is inside the cover? so we can use that offset for ARView and in Mapview as well.
