Detect Orientation using Accelerometer and Magnetic Field sensors

The post Detect Android device rotation, using Accelerometer sensor base on accelerometer only. It is another method to obtain it using both Accelerometer and Magnetic Field sensors together.

Example:

package com.AndroidDetOrientation;

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 AndroidDetOrientationActivity extends Activity 
 implements SensorEventListener{
 
 SensorManager sensorManager;
 private Sensor sensorAccelerometer;
 private Sensor sensorMagneticField;
 
 private float[] valuesAccelerometer;
 private float[] valuesMagneticField;
 
 private float[] matrixR;
 private float[] matrixI;
 private float[] matrixValues;
 
 TextView readingAzimuth, readingPitch, readingRoll;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        readingAzimuth = (TextView)findViewById(R.id.azimuth);
        readingPitch = (TextView)findViewById(R.id.pitch);
        readingRoll = (TextView)findViewById(R.id.roll);
        
        sensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);
        sensorAccelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
     sensorMagneticField = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
        
     valuesAccelerometer = new float[3];
     valuesMagneticField = new float[3];
     
     matrixR = new float[9];
     matrixI = new float[9];
     matrixValues = new float[3];
    }
    
 @Override
 protected void onResume() {

  sensorManager.registerListener(this, 
    sensorAccelerometer, 
    SensorManager.SENSOR_DELAY_NORMAL);
  sensorManager.registerListener(this, 
    sensorMagneticField, 
    SensorManager.SENSOR_DELAY_NORMAL);
  super.onResume();
 }

 @Override
 protected void onPause() {

  sensorManager.unregisterListener(this, 
    sensorAccelerometer);
  sensorManager.unregisterListener(this, 
    sensorMagneticField);
  super.onPause();
 }

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

 @Override
 public void onSensorChanged(SensorEvent event) {
  // TODO Auto-generated method stub
  
  switch(event.sensor.getType()){
  case Sensor.TYPE_ACCELEROMETER:
   for(int i =0; i < 3; i++){
    valuesAccelerometer[i] = event.values[i];
   }
   break;
  case Sensor.TYPE_MAGNETIC_FIELD:
   for(int i =0; i < 3; i++){
    valuesMagneticField[i] = event.values[i];
   }
   break;
  }
  
  boolean success = SensorManager.getRotationMatrix(
       matrixR, 
       matrixI, 
       valuesAccelerometer, 
       valuesMagneticField);
  
  if(success){
   SensorManager.getOrientation(matrixR, matrixValues);
   
   double azimuth = Math.toDegrees(matrixValues[0]);
   double pitch = Math.toDegrees(matrixValues[1]);
   double roll = Math.toDegrees(matrixValues[2]);
   
   readingAzimuth.setText("Azimuth: " + String.valueOf(azimuth));
   readingPitch.setText("Pitch: " + String.valueOf(pitch));
   readingRoll.setText("Roll: " + String.valueOf(roll));
  }
  
 }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <TextView
        android:id="@+id/azimuth" 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>
    <TextView
        android:id="@+id/pitch" 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>
    <TextView
        android:id="@+id/roll" 
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

</LinearLayout>

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