Android Accelerometer Example


In this sample application we will put the android accelerometer sensor into use . Nowadays accelerometer is used more in motion games where the user tilts the phone for a specific action to take place or used for shake detection. It has become common to shake the device to reset the application or erase a canvas in paint apps.

In this example we will change the image in the ImageView with respect to the users actions (like tilting the phone up,down right and left).Like we used for the proximity sensor example we use the SensorManager class and get the accelerometer sensor service. On the overridden method onSensorChanged we monitor the sensor values of all 3 axises (x ,y & z). Keep a threshold valued of 2.0 for center and change the image according the the axis values. Hope you got the idea.


Now lets start:

1.Create a new project File ->New -> Project ->Android ->Android Application Project. While creating the new project, name the activity as AccelerometerActivity(AccelerometerActivity.java) and layout as activity_accelerometer.xml.

2.Now let us design the UI for the AccelerometerActivity i.e activity_accelerometer.xml with an ImageView and a TextView.Have images in drawable folder to differentiate each tilting motion(Here I have images for center,top,right,bottom and left).

activity_accelerometer.xml

 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/relative"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >
<TextView
android:id="@+id/txt"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="20dp"
android:text="Tilt the phone to see the difference" />

<ImageView
android:id="@+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="@+id/txt"
android:layout_centerHorizontal="true"
android:scaleType="fitXY"
android:src="@drawable/center" />
</RelativeLayout>

3.Now in the AccelerometerActivity use a logic to identify the tilting action and replace the images accordingly. Do not forget to unregister the sensor to save battery.

AccelerometerActivity.java 

import android.app.Activity;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.TextView;

public class AccelerometerActivity extends Activity implements
  SensorEventListener {

 private SensorManager mSensorManager;
 private Sensor mAccelerometer;
 TextView title;
 ImageView iv;

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_accelerometer);
  mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
  mAccelerometer = mSensorManager
    .getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
  title = (TextView) findViewById(R.id.txt);
  iv = (ImageView) findViewById(R.id.imageView1);
 }

 @Override
 public void onAccuracyChanged(Sensor arg0, int arg1) {
  // TODO Auto-generated method stub
 }

 @Override
 public void onSensorChanged(SensorEvent event) {
  float x = event.values[0];
  float y = event.values[1];
  float z = event.values[2];
  if (Math.abs(x) > Math.abs(y)) {
   if (x < 0) {
    iv.setImageResource(R.drawable.right);
   }
   if (x > 0) {
    iv.setImageResource(R.drawable.left);
   }
  } else {
   if (y < 0) {
    iv.setImageResource(R.drawable.top);
   }
   if (y > 0) {
    iv.setImageResource(R.drawable.bottom);
   }
  }
  if (x > (-2) && x < (2) && y > (-2) && y < (2)) {
   iv.setImageResource(R.drawable.center);
  }
 }

 @Override
 protected void onResume() {
  super.onResume();
  mSensorManager.registerListener(this, mAccelerometer,
    SensorManager.SENSOR_DELAY_NORMAL);
 }

 @Override
 protected void onPause() {
  super.onPause();
  mSensorManager.unregisterListener(this);
 }
}


4.Run the project by rightclicking project Run as → android project in an android device.

Output:

The output of this example would be similar to the one as follows:

 


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