What does Core Motion error 102 mean?

Question

I use Core Motion\'s sensor fusing to get north oriented motion updates:

[motionManager startDeviceMotionUpdatesUsingReferenceFrame:CMAttitudeReferenceFrameX         


        

Answer 1

From documentation

typedef enum {
   CMErrorNULL = 100,
   CMErrorDeviceRequiresMovement,
   CMErrorTrueNorthNotAvailable
} CMError;

It seems error 102 is CMErrorTrueNorthNotAvailable, and its description is

CMErrorTrueNorthNotAvailable

It seems not much information is available regarding what causes this error. It can be any hardware issue with the device.