Orientation from Android Accelerometer

just wanted to add something to Hartok's answer as I couldn't understand it at first...

I've rewritten the method to be:

public static float[] adjustAccelOrientation(int displayRotation, float[] eventValues) 
{ 
    float[] adjustedValues = new float[3];

    final int axisSwap[][] = {
    {  1,  -1,  0,  1  },     // ROTATION_0 
    {-1,  -1,  1,  0  },     // ROTATION_90 
    {-1,    1,  0,  1  },     // ROTATION_180 
    {  1,    1,  1,  0  }  }; // ROTATION_270 

    final int[] as = axisSwap[displayRotation]; 
    adjustedValues[0]  =  (float)as[0] * eventValues[ as[2] ]; 
    adjustedValues[1]  =  (float)as[1] * eventValues[ as[3] ]; 
    adjustedValues[2]  =  eventValues[2];

    return adjustedValues;
}

Exactly the same thing, just with more user friendly variable names and I recreate the float internally because I needed it like that... Simply call this function, put in the getRotation and the event.values float array, check the values of its return float array and pick whatever number you prefer...

Hope this helps someone!

As far as I know this is because of default orientation of device. F.e. new android tablets with Honeycomb have portrait orientation when held like in landscape on phones.

http://developer.android.com/reference/android/hardware/SensorEvent.html

In android documentation there is information that:

The coordinate-system is defined relative to the screen of the phone in its default orientation. The axes are not swapped when the device's screen orientation changes.

The X axis is horizontal and points to the right, the Y axis is vertical and points up and the Z axis points towards the outside of the front face of the screen. In this system, coordinates behind the screen have negative Z values.

Maybe one of this devices has also landscape as a portrait (default) orientation?

Hope it helps you somehow.