If you want to create Sensor function you can use my below example code. The android platform supports three categories of sensors. 1st Motion Sensors, 2nd Environmental sensors and 3rd is Position sensors. In the below code I have used SensorEventListener method. See the below example it will clearly desdcribed you how to make sensor function.

Step(1)-activity_main.xml

<RelativeLayout xmlns:androclass="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=".MainActivity" >  

    <TextView  
        android:id="@+id/textView1"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_alignParentLeft="true"  
        android:layout_alignParentTop="true"  
        android:layout_marginLeft="85dp"  
        android:layout_marginTop="104dp"  
        android:text="Sensor Device" />  

</RelativeLayout>  

Step(2)-MainActivity-

public class MainActivity extends Activity {  
    SensorManager sm = null;  
    TextView textView1 = null;  
    List list;  

    SensorEventListener sel = new SensorEventListener(){  
        public void onAccuracyChanged(Sensor sensor, int accuracy) {}  
        public void onSensorChanged(SensorEvent event) {  
            float[] values = event.values;  
            textView1.setText("x: "+values[0]+"\ny: "+values[1]+"\nz: "+values[2]);  
        }  
    };  

    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  

        /* Get a SensorManager instance */  
        sm = (SensorManager)getSystemService(SENSOR_SERVICE);  

        textView1 = (TextView)findViewById(R.id.textView1);  

        list = sm.getSensorList(Sensor.TYPE_ACCELEROMETER);  
        if(list.size()>0){  
            sm.registerListener(sel, (Sensor) list.get(0), SensorManager.SENSOR_DELAY_NORMAL);  
        }else{  
            Toast.makeText(getBaseContext(), "Error: No Accelerometer.", Toast.LENGTH_LONG).show();  
        }  
    }  

    @Override  
    protected void onStop() {  
        if(list.size()>0){  
          sm.unregisterListener(sel);  
        }  
        super.onStop();  
    }  
}