Android 5 Rotation Vector Sensor is not accurate

Question

I ran into a problem with a rotation sensor, with a type TYPE_ROTATION_VECTOR. Reading from the sensor seems inaccurate, or is it something bothering, it's hard for me to say. This is the code I use to ensure the actual rotation of the device:

public void onSensorChanged(SensorEvent event) {
    if (event.sensor.getType() == Sensor.TYPE_ROTATION_VECTOR) {
        if (prevRotMatrix == null) {
            prevRotMatrix = new float[16];
            SensorManager.getRotationMatrixFromVector(prevRotMatrix, event.values);
        } else {
            float[] deltas = new float[3];
            SensorManager.getRotationMatrixFromVector(rotMatrix, event.values);
            SensorManager.getAngleChange(deltas, rotMatrix, prevRotMatrix);

            rotXVal += (float) Math.toDegrees(deltas[1]);
            rotYVal += (float) Math.toDegrees(deltas[2]);
            rotZVal += (float) Math.toDegrees(deltas[0]);

            client.rotX(rotXVal);
            client.rotY(rotYVal);
            client.rotZ(rotZVal);

            System.arraycopy(rotMatrix, 0, prevRotMatrix, 0, rotMatrix.length);
        }
    }
}

rotXVal, rotYVal rotZVal .
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, Android Lollipop (Samsung Galaxy S6). KitKat (Samsung Galaxy Note 4), .
RotationVectorDemo. Lollipop, KitKat.

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