The ClaimCompass() method

ClaimCompass ();

To start receiving compass heading updates from the proxy, the application must call the net.hadess.SensorProxy.ClaimCompass() method. It can do so whether a compass is available or not, updates would then be sent when such a sensor appears.

Applications should call net.hadess.SensorProxy.ReleaseCompass() when readings are not required anymore. This prevents the sensor proxy from polling the device, thus increasing wake-ups and reducing battery life.

Note that Compass information is only available to Geoclue by default, which will proxy the magnetic heading information, and transform it to True North heading.

The ReleaseCompass() method

ReleaseCompass ();

This should be called as soon as readings are not required anymore. Note that resources are freed up if a monitoring application exits without calling net.hadess.SensorProxy.ReleaseCompass(), crashes or the sensor disappears.

The "HasCompass" property

HasCompass  readable   b

Whether a supported compass is present on the system.

The "CompassHeading" property

CompassHeading  readable   d

The compass heading in degrees with respect to magnetic North direction, in clockwise order. That means North becomes 0 degree, East: 90 degrees, South: 180 degrees, West: 270 degrees and so on. When unknown, it's set to -1.0.