Angle of phone rotated along X axis

Question

I am working on an Android app wherein I want to scroll a large image horizontally. I used the accelerometer (Sensor.TYPE_ACCELEROMETER) and magnetic field (Sensor.TYPE_MAGNETIC_FIELD) data to get the angle of rotation. This data being to frequent infested with noise I am not able to implement a smooth motion effect.

@Override
public void onSensorChanged(SensorEvent event) {
    switch (event.sensor.getType()) {
        case Sensor.TYPE_MAGNETIC_FIELD:
            mags = event.values.clone();
            break;
        case Sensor.TYPE_ACCELEROMETER:
            accels = event.values.clone();
            break;
    }

    if (mags != null && accels != null) {
        gravity = new float[16];
        boolean success = SensorManager.getRotationMatrix(gravity, null, accels, mags);
        if (success) {
            float[] outGravity = new float[16];
            SensorManager.remapCoordinateSystem(gravity, SensorManager.AXIS_X, SensorManager.AXIS_Z, outGravity);
            SensorManager.getOrientation(outGravity, values);

            rollingAverage[0] = roll(rollingAverage[0], values[0]);
            rollingAverage[1] = roll(rollingAverage[1], values[1]);
            rollingAverage[2] = roll(rollingAverage[2], values[2]);

            azimuth = Math.toDegrees(values[0]);
            pitch = Math.toDegrees(values[1]);
            roll = Math.toDegrees(values[2]);
            mags = null;
            accels = null;

            double diffRoll = lastRoll - roll;
            double diffPitch = lastPitch - pitch;
            long curTime = System.currentTimeMillis();
            if (Math.abs(diffRoll) >= 2) {
                if (diffRoll > 0)
                    imageView.panLeft();
                else
                    imageView.panRight();
                lastRoll = roll;
            }
        }
    }
}

Any ideas on achieving this using other methods?

Answer 1

You have to implement sensor fusion techniques based on Kalman filter or other filters. You can use open source libraries if needed. Refer this bitbucket repository . If you want to do yourself, read the tutorial.