Want to contribute to Android port to N9? Help needed with compass

NITDroid maintainer, e-yes, has asked if anyone would be willing to contribute with the implementation of some aspects of the port: I've created basic implementation of Magnetic Field sensor (compass) for Nokia N9. Some applications even able to use it (e.g Smart Compass from Play.Store). However, most applications fail to use compass HAL. Reasons: 1) raw values reported by driver are out-of-range (or smth like that). 2) lack of calibration (I suppose we need to do some sort of matrix transform on data in HAL).

Any one willing to contribute, feel free to start with this relatively easy task.