How to detect movement of an android device?

Question

I need suggestion about how to detect the amount of movement of an android device. Suppose I have put the phone on a table or bed and then if somebody taps the table or sits

Answer 1

I used the following class:

public class MovementDetector implements SensorEventListener {

protected final String TAG = getClass().getSimpleName();

private SensorManager sensorMan;
private Sensor accelerometer;

private MovementDetector() {
}

private static MovementDetector mInstance;

public static MovementDetector getInstance() {
    if (mInstance == null) {
        mInstance = new MovementDetector();
        mInstance.init();
    }
    return mInstance;
}

//////////////////////
private HashSet mListeners = new HashSet();

private void init() {
    sensorMan = (SensorManager) GlobalData.getInstance().getContext().getSystemService(Context.SENSOR_SERVICE);
    accelerometer = sensorMan.getDefaultSensor(Sensor.TYPE_LINEAR_ACCELERATION);
}

public void start() {
    sensorMan.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_NORMAL);
}

public void stop() {
    sensorMan.unregisterListener(this);
}

public void addListener(Listener listener) {
    mListeners.add(listener);
}

/* (non-Javadoc)
 * @see android.hardware.SensorEventListener#onSensorChanged(android.hardware.SensorEvent)
 */
@Override
public void onSensorChanged(SensorEvent event) {
    if (event.sensor.getType() == Sensor.TYPE_LINEAR_ACCELERATION) {

        float x = event.values[0];
        float y = event.values[1];
        float z = event.values[2];

        float diff = (float) Math.sqrt(x * x + y * y + z * z);
        if (diff > 0.5) // 0.5 is a threshold, you can test it and change it
            Log.d(TAG,"Device motion detected!!!!");
        for (Listener listener : mListeners) {
            listener.onMotionDetected(event, diff);
        }
    }

}

/* (non-Javadoc)
 * @see android.hardware.SensorEventListener#onAccuracyChanged(android.hardware.Sensor, int)
 */
@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
    // TODO Auto-generated method stub

}

public interface Listener {
    void onMotionDetected(SensorEvent event, float acceleration);
    }
}

Usage:

On my activity onCrate():

        MovementDetector.getInstance().addListener(new MovementDetector.Listener() {

        @Override
        public void onMotionDetected(SensorEvent event, float acceleration) {

            mMotionDetectionTextView.setText("Acceleration: ["+String.format("%.3f",event.values[0])+","+String.format("%.3f",event.values[1])+","+String.format("%.3f",event.values[2])+"] "+String.format("%.3f", acceleration));
            if (acceleration > SettingsHelper.getInstance().getMotionDetectionThreshold()){
                mMotionDetectionTextView.setTextColor(Color.RED);
            } else {
                mMotionDetectionTextView.setTextColor(Color.WHITE);
            }

        }
    });

On my activity onResume():

MovementDetector.getInstance().start();

On my activity onPause():

MovementDetector.getInstance().stop();