ios accelerometer values at any orientation

Question

Accelerometer values are provided with respect to the device orientation..

My goal is to get these values irrespective of the device position.

In a considered s

Answer 1

Its quite simple actually, just start generating device motion updates using a reference frame:

- (void)startDeviceMotionUpdatesUsingReferenceFrame:(CMAttitudeReferenceFrame)referenceFrame

Depending on what you want to achieve you can select one of the different options

typedef enum {
   CMAttitudeReferenceFrameXArbitraryZVertical = 1 << 0,
   CMAttitudeReferenceFrameXArbitraryCorrectedZVertical = 1 << 1,
   CMAttitudeReferenceFrameXMagneticNorthZVertical = 1 << 2,
   CMAttitudeReferenceFrameXTrueNorthZVertical = 1 << 3
} CMAttitudeReferenceFrame;

For example, by using "CMAttitudeReferenceFrameXMagneticNorthZVertical" the readings you get from the acceleration would be constant regardless of the device position (they get aligned with "gravity" bellow" and "north" in front). I don't remember the exact reference position but i believe the "top of the phone" points north while the "screen of the phone" points up.