Saturday, May 24, 2014

Accelerometer Basic Example - Detect Phone Shake Motion

In this example detecting Accelerometer Motion, when Accelerometer force value cross thersold showing an alert for motion detected.

Use:

  1. You can use this example in games based on Accelerometer Motion (Phone Tilt).
  2. You can use this example for battary consumption when using GPS Calls. Combine Screen Wake Sleep Example with this example to consume less battary when calling GPS calls.Later We will give combined example to consume less battery.


Note:


Check this example in real device.

Project Structure:




File : src/AccelerometerListener.java

Create Interface AccelerometerListener and create method onShake, we will override this function in main activity file and listener will call this method when motion detected.

  1. public interface AccelerometerListener {
  2.   
  3.  public void onAccelerationChanged(float x, float y, float z);
  4.  
  5.  public void onShake(float force);
  6.  
  7. }

File : src/MainAccelerometer.java

This is the maain file aand Start Accelerometer listening on Activity onResume and stop Accelerometer listening on Activity onStop and onDestroy

  1. package com.androidexample.accelerometerexample;
  2.  
  3. import android.os.Bundle;
  4. import android.app.Activity;
  5. import android.util.Log;
  6. import android.widget.Toast;
  7.  
  8. public class MainAccelerometer extends Activity implements AccelerometerListener{
  9.  
  10.  @Override
  11.  protected void onCreate(Bundle savedInstanceState) {
  12.   super.onCreate(savedInstanceState);
  13.   setContentView(R.layout.accelerometer_example_main);
  14.   
  15.   // Check onResume Method to start accelerometer listener
  16.  }
  17.    
  18.  public void onAccelerationChanged(float x, float y, float z) {
  19.   // TODO Auto-generated method stub
  20.   
  21.  }
  22.  
  23.  public void onShake(float force) {
  24.   
  25.         // Do your stuff here
  26.         
  27.   // Called when Motion Detected
  28.   Toast.makeText(getBaseContext(), "Motion detected", 
  29.     Toast.LENGTH_SHORT).show();
  30.   
  31.  }
  32.  
  33.  @Override
  34.     public void onResume() {
  35.             super.onResume();
  36.             Toast.makeText(getBaseContext(), "onResume Accelerometer Started", 
  37.               Toast.LENGTH_SHORT).show();
  38.             
  39.             //Check device supported Accelerometer senssor or not
  40.             if (AccelerometerManager.isSupported(this)) {
  41.              
  42.              //Start Accelerometer Listening
  43.        AccelerometerManager.startListening(this);
  44.             }
  45.     }
  46.  
  47.  @Override
  48.     public void onStop() {
  49.             super.onStop();
  50.             
  51.             //Check device supported Accelerometer senssor or not
  52.             if (AccelerometerManager.isListening()) {
  53.              
  54.              //Start Accelerometer Listening
  55.        AccelerometerManager.stopListening();
  56.        
  57.        Toast.makeText(getBaseContext(), "onStop Accelerometer Stoped", 
  58.                          Toast.LENGTH_SHORT).show();
  59.             }
  60.            
  61.     }
  62.  
  63.  @Override
  64.  public void onDestroy() {
  65.   super.onDestroy();
  66.   Log.i("Sensor", "Service  distroy");
  67.   
  68.   //Check device supported Accelerometer senssor or not
  69.   if (AccelerometerManager.isListening()) {
  70.    
  71.    //Start Accelerometer Listening
  72.    AccelerometerManager.stopListening();
  73.    
  74.    Toast.makeText(getBaseContext(), "onDestroy Accelerometer Stoped", 
  75.                    Toast.LENGTH_SHORT).show();
  76.         }
  77.    
  78.  }
  79.  
  80. }

File : src/AccelerometerManager.java

In this class define functions to start acclerometer sensor related functions like.. Check for acclerometer sensor,start acclerometer sensor,stop acclerometer sensor.

  1. import java.util.List;
  2. import android.content.Context;
  3. import android.hardware.Sensor;
  4. import android.hardware.SensorEvent;
  5. import android.hardware.SensorEventListener;
  6. import android.hardware.SensorManager;
  7. import android.widget.Toast;
  8.  
  9. public class AccelerometerManager {
  10.  
  11.  private static Context aContext=null;
  12.  
  13.  
  14.     /** Accuracy configuration */
  15.     private static float threshold  = 15.0f; 
  16.     private static int interval     = 200;
  17.  
  18.     private static Sensor sensor;
  19.     private static SensorManager sensorManager;
  20.     // you could use an OrientationListener array instead
  21.     // if you plans to use more than one listener
  22.     private static AccelerometerListener listener;
  23.  
  24.     /** indicates whether or not Accelerometer Sensor is supported */
  25.     private static Boolean supported;
  26.     /** indicates whether or not Accelerometer Sensor is running */
  27.     private static boolean running = false;
  28.  
  29.     /**
  30.      * Returns true if the manager is listening to orientation changes
  31.      */
  32.     public static boolean isListening() {
  33.         return running;
  34.     }
  35.  
  36.     /**
  37.      * Unregisters listeners
  38.      */
  39.     public static void stopListening() {
  40.         running = false;
  41.         try {
  42.             if (sensorManager != null && sensorEventListener != null) {
  43.                 sensorManager.unregisterListener(sensorEventListener);
  44.             }
  45.         } catch (Exception e) {}
  46.     }
  47.  
  48.     /**
  49.      * Returns true if at least one Accelerometer sensor is available
  50.      */
  51.     public static boolean isSupported(Context context) {
  52.      aContext = context;
  53.         if (supported == null) {
  54.             if (aContext != null) {
  55.              
  56.              
  57.                 sensorManager = (SensorManager) aContext.
  58.                         getSystemService(Context.SENSOR_SERVICE);
  59.                 
  60.                 // Get all sensors in device
  61.                 List sensors = sensorManager.getSensorList(
  62.                         Sensor.TYPE_ACCELEROMETER);
  63.                 
  64.                 supported = new Boolean(sensors.size() > 0);
  65.                 
  66.                 
  67.                 
  68.             } else {
  69.                 supported = Boolean.FALSE;
  70.             }
  71.         }
  72.         return supported;
  73.     }
  74.  
  75.     /**
  76.      * Configure the listener for shaking
  77.      * @param threshold
  78.      *             minimum acceleration variation for considering shaking
  79.      * @param interval
  80.      *             minimum interval between to shake events
  81.      */
  82.     public static void configure(int threshold, int interval) {
  83.         AccelerometerManager.threshold = threshold;
  84.         AccelerometerManager.interval = interval;
  85.     }
  86.  
  87.     /**
  88.      * Registers a listener and start listening
  89.      * @param accelerometerListener
  90.      *             callback for accelerometer events
  91.      */
  92.     public static void startListening( AccelerometerListener accelerometerListener ) 
  93.     {
  94.      
  95.         sensorManager = (SensorManager) aContext.
  96.                 getSystemService(Context.SENSOR_SERVICE);
  97.         
  98.         // Take all sensors in device
  99.         List sensors = sensorManager.getSensorList(
  100.                 Sensor.TYPE_ACCELEROMETER);
  101.         
  102.         if (sensors.size() > 0) {
  103.          
  104.             sensor = sensors.get(0);
  105.             
  106.             // Register Accelerometer Listener
  107.             running = sensorManager.registerListener(
  108.                     sensorEventListener, sensor, 
  109.                     SensorManager.SENSOR_DELAY_GAME);
  110.             
  111.             listener = accelerometerListener;
  112.         }
  113.         
  114.   
  115.     }
  116.  
  117.     /**
  118.      * Configures threshold and interval
  119.      * And registers a listener and start listening
  120.      * @param accelerometerListener
  121.      *             callback for accelerometer events
  122.      * @param threshold
  123.      *             minimum acceleration variation for considering shaking
  124.      * @param interval
  125.      *             minimum interval between to shake events
  126.      */
  127.     public static void startListening(
  128.             AccelerometerListener accelerometerListener, 
  129.             int threshold, int interval) {
  130.         configure(threshold, interval);
  131.         startListening(accelerometerListener);
  132.     }
  133.  
  134.     /**
  135.      * The listener that listen to events from the accelerometer listener
  136.      */
  137.     private static SensorEventListener sensorEventListener = 
  138.         new SensorEventListener() {
  139.  
  140.         private long now = 0;
  141.         private long timeDiff = 0;
  142.         private long lastUpdate = 0;
  143.         private long lastShake = 0;
  144.  
  145.         private float x = 0;
  146.         private float y = 0;
  147.         private float z = 0;
  148.         private float lastX = 0;
  149.         private float lastY = 0;
  150.         private float lastZ = 0;
  151.         private float force = 0;
  152.  
  153.         public void onAccuracyChanged(Sensor sensor, int accuracy) {}
  154.  
  155.         public void onSensorChanged(SensorEvent event) {
  156.             // use the event timestamp as reference
  157.             // so the manager precision won't depends 
  158.             // on the AccelerometerListener implementation
  159.             // processing time
  160.             now = event.timestamp;
  161.  
  162.             x = event.values[0];
  163.             y = event.values[1];
  164.             z = event.values[2];
  165.  
  166.             // if not interesting in shake events
  167.             // just remove the whole if then else block
  168.             if (lastUpdate == 0) {
  169.                 lastUpdate = now;
  170.                 lastShake = now;
  171.                 lastX = x;
  172.                 lastY = y;
  173.                 lastZ = z;
  174.                 Toast.makeText(aContext,"No Motion detected", 
  175.                    Toast.LENGTH_SHORT).show();
  176.              
  177.             } else {
  178.                 timeDiff = now - lastUpdate;
  179.                
  180.                 if (timeDiff > 0) { 
  181.                  
  182.                     /*force = Math.abs(x + y + z - lastX - lastY - lastZ) 
  183.                                 / timeDiff;*/ 
  184.                     force = Math.abs(x + y + z - lastX - lastY - lastZ);
  185.                  
  186.                  if (Float.compare(force, threshold) >0 ) {
  187.                      //Toast.makeText(Accelerometer.getContext(), 
  188.                         //(now-lastShake)+"  >= "+interval, 1000).show();
  189.                         
  190.                         if (now - lastShake >= interval) { 
  191.                          
  192.                             // trigger shake event
  193.                             listener.onShake(force);
  194.                         }
  195.                         else
  196.                         {
  197.                          Toast.makeText(aContext,"No Motion detected", 
  198.                                 Toast.LENGTH_SHORT).show();
  199.                          
  200.                         }
  201.                         lastShake = now;
  202.                     }
  203.                     lastX = x;
  204.                     lastY = y;
  205.                     lastZ = z;
  206.                     lastUpdate = now; 
  207.                 }
  208.                 else
  209.                 {
  210.                  Toast.makeText(aContext,"No Motion detected", Toast.LENGTH_SHORT).show();
  211.                  
  212.                 }
  213.             }
  214.             // trigger change event
  215.             listener.onAccelerationChanged(x, y, z);
  216.         }
  217.  
  218.     };
  219.  
  220. }

File : AndroidMainifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.androidexample.accelerometerexample"
    android:versionCode="1"
    android:versionName="1.0" >

     <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="10" />

     <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.androidexample.accelerometerexample.MainAccelerometer"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                 <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
<uses-permission android:name="android.permission.READ_PHONE_STATE"></uses-permission>
</manifest>

File : accelerometer_example_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainAccelerometer" >

     <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="Shake / Tilt Your Phone To Get Accelerometer Motion Alerts" />

 </RelativeLayout>

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