How to use the Light sensor on Android

If your android device has a Light Sensor you can use it in your applications. It provide the value in lux units as described here. More about lux find here.

main.xml

main.java

package com.blog.lightsensor;

import java.util.Date;

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

public class main extends Activity implements SensorEventListener {
 private  SensorManager sensorManager = null;
 private  Sensor currentSensor = null; 
 
 @Override
 public void onResume(){
  super.onResume();
  if(currentSensor != null)sensorManager.registerListener(this, currentSensor, SensorManager.SENSOR_DELAY_FASTEST);
 }
 
 @Override
 public void onPause(){
  super.onPause();
  sensorManager.unregisterListener(this);
 } 
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
     sensorManager = (SensorManager) this.getSystemService(SENSOR_SERVICE);
  currentSensor = sensorManager.getDefaultSensor(Sensor.TYPE_LIGHT );
  if(currentSensor != null){
   sensorManager.registerListener(this, currentSensor, SensorManager.SENSOR_DELAY_FASTEST);
  }else{
   ((TextView) findViewById(R.id.textView1)).setText("Can't initialize the LIGHT sensor.");   
  } 
    }

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

 @Override
 public void onSensorChanged(SensorEvent event) {
  // TODO Auto-generated method stub
  
  if (event.sensor.getType() == Sensor.TYPE_LIGHT){   
   TextView tv = (TextView) findViewById(R.id.textView1);
   tv.setText( tv.getText()+ "value: " +event.values[0] + " lux , time: " + new Date() + "\n");   
  }
 }
}