I'm playing with the motion functions right now because I want to create some kind of compass and spirit level app. Does anyone have any good links to documents which explain the values I get from magnetometer etc.? Thanks a lot!
Though not specific to pythonista, http://inst.eecs.berkeley.edu/~msdosx/fa11/lectures/Lecture24.pdf gives a good overview of the coordinate systems and conventions for most of what comes from the motion lib.
These are just thin wrappers around the iOS CoreMotion lib. generally you get a 3 vector in device coordinates that represent the gravity vector (in g), magnetic field vector, (in uT i think). The fourth tuple in magnetic field is calibration indicator. get attitude gives you the euler angles, in radian.
Thanks a lot. Especially "CMMotionManager" mentioned in the document was a very good keyword for further searches. :-)