Today I’m going to share a working code to make a very simple compass application for your android device.
 
Some android device (like Huawei Y300 and Lenovo P700i) does not have full support of motions sensors so this code will not work for them.

Video Demo

Our code for today will run just like this:
 
 
 
 

Files Needed

You need to create your own compass image. For this example, I’m using a stock photo. Your image must be a PNG with transparent background, do not use this jpg file I used.

👁 img_compass

Let’s Code

Here’s our MainActivity.java

package com.example.compassapp;

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.view.animation.Animation;
import android.view.animation.RotateAnimation;
import android.widget.ImageView;
import android.widget.TextView;

public class MainActivity extends Activity implements SensorEventListener {

 // define the display assembly compass picture
 private ImageView image;

 // record the compass picture angle turned
 private float currentDegree = 0f;

 // device sensor manager
 private SensorManager mSensorManager;

 TextView tvHeading;

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

 // 
 image = (ImageView) findViewById(R.id.main_iv);

 // TextView that will tell the user what degree is he heading
 tvHeading = (TextView) findViewById(R.id.tvHeading);

 // initialize your android device sensor capabilities
 mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
 }

 @Override
 protected void onResume() {
 super.onResume();

 // for the system's orientation sensor registered listeners
 mSensorManager.registerListener(this, mSensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION),
 SensorManager.SENSOR_DELAY_GAME);
 }

 @Override
 protected void onPause() {
 super.onPause();

 // to stop the listener and save battery
 mSensorManager.unregisterListener(this);
 }

 @Override
 public void onSensorChanged(SensorEvent event) {

 // get the angle around the z-axis rotated
 float degree = Math.round(event.values[0]);

 tvHeading.setText("Heading: " + Float.toString(degree) + " degrees");

 // create a rotation animation (reverse turn degree degrees)
 RotateAnimation ra = new RotateAnimation(
 currentDegree, 
 -degree,
 Animation.RELATIVE_TO_SELF, 0.5f, 
 Animation.RELATIVE_TO_SELF,
 0.5f);

 // how long the animation will take place
 ra.setDuration(210);

 // set the animation after the end of the reservation status
 ra.setFillAfter(true);

 // Start the animation
 image.startAnimation(ra);
 currentDegree = -degree;

 }

 @Override
 public void onAccuracyChanged(Sensor sensor, int accuracy) {
 // not in use
 }
}

Our layout file activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:background="#fff" >

 <TextView
 android:id="@+id/tvHeading"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_centerHorizontal="true"
 android:layout_marginBottom="40dp"
 android:layout_marginTop="20dp"
 android:text="Heading: 0.0" />

 <ImageView
 android:id="@+id/imageViewCompass"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_below="@+id/tvHeading"
 android:layout_centerHorizontal="true"
 android:src="@drawable/img_compass" />

</RelativeLayout>

Source Code Download

You can download this sample project here: CompassApp.zip

Some notes

My app orientation is locked to portrait mode. There are no special permissions in the Manifest file.

Further Readings

• Android SensorManager
• Android RotateAnimation
• Android Motion Sensors