Android SensorManager strange how to remapCoordinateSystem

Question

API Demos -> Graphics -> Compass

It works properly only, until you don\'t change the device natural orientation. In most phones is the portrait and most 10 inch tabl

Answer 1

If the phone UI locked to the rotation 0, I am getting the following values without remapCoordinateSystem()

Pitch (phone) = -Pitch   (API)
Roll  (phone) =  Roll     (API)
Yaw   (phone) =  Azimuth  (API)

• at least near 0,0,0 values.

If the phone UI forced to rotation 90:

Yaw value has -90 degree ( - PI/2 ) at old orientation!!! => I will go to East in reality instead of North.

If I take phone to 0,0,0 position:

Pitch (phone) = -Roll    (API)
Roll  (phone) = -Pitch   (API)
Yaw   (phone) =  Azimuth (API)

If the phone UI forced to rotation 180:

Yaw value has +/-180 degree ( +/- PI ) at old orientation!!! => I will go to South in reality instead of North.

If I take phone to 0,0,0 position:

Pitch (phone) =  Pitch   (API)
Roll  (phone) = -Roll    (API)
Yaw   (phone) =  Azimuth (API)

If the phone UI forced to rotation 270:

Yaw value has +90 degree ( + PI/2 ) at old orientation!!! => I will go to West in reality instead of North.

If I take phone to 0,0,0 position:

Pitch (phone) =  Roll    (API)
Roll  (phone) =  Pitch   (API)
Yaw   (phone) =  Azimuth (API)

I wrote a little fix, and tested with: android:screenOrientation="fullSensor"

public static final void fixRotation0(float[] orientation) { //azimuth, pitch, roll
    orientation[1] = -orientation[1]; // pitch = -pitch
}

public static final void fixRotation90(float[] orientation) { //azimuth, pitch, roll
    orientation[0] += Math.PI / 2f; // offset
    float tmpOldPitch = orientation[1];
    orientation[1] = -orientation[2]; //pitch = -roll
    orientation[2] = -tmpOldPitch; // roll  = -pitch    
}

public static final void fixRotation180(float[] orientation) { //azimuth, pitch, roll
    orientation[0] = (float)(orientation[0] > 0f ? (orientation[0] - Math.PI) : (orientation[0] + Math.PI)); // offset
    orientation[2] = -orientation[2]; // roll = -roll
}

public static final void fixRotation270(float[] orientation) { //azimuth, pitch, roll
    orientation[0] -= Math.PI / 2; // offset
    float tmpOldPitch = orientation[1];
    orientation[1] = orientation[2]; //pitch = roll
    orientation[2] = tmpOldPitch; // roll  = pitch  
}

In most cases is working. When you rotate quickly 180 degree around 1 axis, than the system will be screwed!

The full code available at Github