How to detect shake event with android?

Question

From the code point of view, you need to implement the SensorListener:

public class ShakeActivity extends Activity implements SensorListener

You will need to acquire a SensorManager:

sensorMgr = (SensorManager) getSystemService(SENSOR_SERVICE);

And register this sensor with desired flags:

sensorMgr.registerListener(this,
SensorManager.SENSOR_ACCELEROMETER,
SensorManager.SENSOR_DELAY_GAME);

In your onSensorChange() method, you determine whether it’s a shake or not:

public void onSensorChanged(int sensor, float[] values) {
  if (sensor == SensorManager.SENSOR_ACCELEROMETER) {
    long curTime = System.currentTimeMillis();
    // only allow one update every 100ms.
    if ((curTime - lastUpdate) > 100) {
      long diffTime = (curTime - lastUpdate);
      lastUpdate = curTime;

      x = values[SensorManager.DATA_X];
      y = values[SensorManager.DATA_Y];
      z = values[SensorManager.DATA_Z];

      float speed = Math.abs(x+y+z - last_x - last_y - last_z) / diffTime * 10000;

      if (speed > SHAKE_THRESHOLD) {
        Log.d("sensor", "shake detected w/ speed: " + speed);
        Toast.makeText(this, "shake detected w/ speed: " + speed, Toast.LENGTH_SHORT).show();
      }
      last_x = x;
      last_y = y;
      last_z = z;
    }
  }
}

The shake threshold is defined as:

private static final int SHAKE_THRESHOLD = 800;

There are some other methods too, to detect shake motion. look at this link.(If that link does not work or link is dead, look at this web archive.).

Have a look at this example for android shake detect listener.

Note: SensorListener is deprecated. we can use SensorEventListener instead. Here is a quick example using SensorEventListener.

Thanks.

Google helps a lot.

/* The following code was written by Matthew Wiggins
 * and is released under the APACHE 2.0 license
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 */
package com.hlidskialf.android.hardware;

import android.hardware.SensorListener;
import android.hardware.SensorManager;
import android.content.Context;
import java.lang.UnsupportedOperationException;

public class ShakeListener implements SensorListener 
{
  private static final int FORCE_THRESHOLD = 350;
  private static final int TIME_THRESHOLD = 100;
  private static final int SHAKE_TIMEOUT = 500;
  private static final int SHAKE_DURATION = 1000;
  private static final int SHAKE_COUNT = 3;

  private SensorManager mSensorMgr;
  private float mLastX=-1.0f, mLastY=-1.0f, mLastZ=-1.0f;
  private long mLastTime;
  private OnShakeListener mShakeListener;
  private Context mContext;
  private int mShakeCount = 0;
  private long mLastShake;
  private long mLastForce;

  public interface OnShakeListener
  {
    public void onShake();
  }

  public ShakeListener(Context context) 
  { 
    mContext = context;
    resume();
  }

  public void setOnShakeListener(OnShakeListener listener)
  {
    mShakeListener = listener;
  }

  public void resume() {
    mSensorMgr = (SensorManager)mContext.getSystemService(Context.SENSOR_SERVICE);
    if (mSensorMgr == null) {
      throw new UnsupportedOperationException("Sensors not supported");
    }
    boolean supported = mSensorMgr.registerListener(this, SensorManager.SENSOR_ACCELEROMETER, SensorManager.SENSOR_DELAY_GAME);
    if (!supported) {
      mSensorMgr.unregisterListener(this, SensorManager.SENSOR_ACCELEROMETER);
      throw new UnsupportedOperationException("Accelerometer not supported");
    }
  }

  public void pause() {
    if (mSensorMgr != null) {
      mSensorMgr.unregisterListener(this, SensorManager.SENSOR_ACCELEROMETER);
      mSensorMgr = null;
    }
  }

  public void onAccuracyChanged(int sensor, int accuracy) { }

  public void onSensorChanged(int sensor, float[] values) 
  {
    if (sensor != SensorManager.SENSOR_ACCELEROMETER) return;
    long now = System.currentTimeMillis();

    if ((now - mLastForce) > SHAKE_TIMEOUT) {
      mShakeCount = 0;
    }

    if ((now - mLastTime) > TIME_THRESHOLD) {
      long diff = now - mLastTime;
      float speed = Math.abs(values[SensorManager.DATA_X] + values[SensorManager.DATA_Y] + values[SensorManager.DATA_Z] - mLastX - mLastY - mLastZ) / diff * 10000;
      if (speed > FORCE_THRESHOLD) {
        if ((++mShakeCount >= SHAKE_COUNT) && (now - mLastShake > SHAKE_DURATION)) {
          mLastShake = now;
          mShakeCount = 0;
          if (mShakeListener != null) { 
            mShakeListener.onShake(); 
          }
        }
        mLastForce = now;
      }
      mLastTime = now;
      mLastX = values[SensorManager.DATA_X];
      mLastY = values[SensorManager.DATA_Y];
      mLastZ = values[SensorManager.DATA_Z];
    }
  }

}

You can also take a look on library Seismic

public class Demo extends Activity implements ShakeDetector.Listener {
  @Override protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    SensorManager sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    ShakeDetector sd = new ShakeDetector(this);
    sd.start(sensorManager);

    TextView tv = new TextView(this);
    tv.setGravity(CENTER);
    tv.setText("Shake me, bro!");
    setContentView(tv, new LayoutParams(MATCH_PARENT, MATCH_PARENT));
  }

  @Override public void hearShake() {
    Toast.makeText(this, "Don't shake me, bro!", Toast.LENGTH_SHORT).show();
  }
}

There are a lot of solutions to this question already, but I wanted to post one that:

• Doesn't use a library depricated in API 3
• Calculates the magnitude of the acceleration correctly
• Correctly applies a timeout between shake events

Here is such a solution:

// variables for shake detection
private static final float SHAKE_THRESHOLD = 3.25f; // m/S**2
private static final int MIN_TIME_BETWEEN_SHAKES_MILLISECS = 1000;
private long mLastShakeTime;
private SensorManager mSensorMgr;

To initialize the timer:

// Get a sensor manager to listen for shakes
mSensorMgr = (SensorManager) getSystemService(SENSOR_SERVICE);

// Listen for shakes
Sensor accelerometer = mSensorMgr.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
if (accelerometer != null) {
    mSensorMgr.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_NORMAL);
}

SensorEventListener methods to override:

@Override
public void onSensorChanged(SensorEvent event) {
    if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
        long curTime = System.currentTimeMillis();
        if ((curTime - mLastShakeTime) > MIN_TIME_BETWEEN_SHAKES_MILLISECS) {

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

            double acceleration = Math.sqrt(Math.pow(x, 2) +
                    Math.pow(y, 2) +
                    Math.pow(z, 2)) - SensorManager.GRAVITY_EARTH;
            Log.d(APP_NAME, "Acceleration is " + acceleration + "m/s^2");

            if (acceleration > SHAKE_THRESHOLD) {
                mLastShakeTime = curTime;
                Log.d(APP_NAME, "Shake, Rattle, and Roll");
            }
        }
    }
}

@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
    // Ignore
}

When you are all done

// Stop listening for shakes
mSensorMgr.unregisterListener(this);