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How to Build an Application to Test Motion Sensors in Android?

  • Last Updated : 28 Jan, 2021

In this article, we will be building a Motion Sensor Testing App Project using Java and XML in Android. The application will be using the hardware of the device to detect the movements. The components required to detect the motion are Accelerometer and Gyroscope. The Accelerometer is an electronic sensor used to detect the device’s position in space by measuring its acceleration and movement. Whereas Gyroscope senses the angular movement of the device. In this app, we will observe a change in the screen’s color as we move the device. There will be a single activity in this application. 

Step by Step Implementation

Step 1: Create a New Project

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.

Step 2: Before going to the coding section first you have to do some pre-task

Add features in AndroidMainfest.xml: We need to add the requirement of hardware needed by this application. The two components that we require are Gyroscope and Accelerometer. Add these following into your AndroidMainfest.xml file. 



<uses-feature android:name=”android.hardware.sensor.accelerometer” android:required=”true”/>

<uses-feature android:name=”android.hardware.sensor.gyroscope” android:required=”true”/>

Create two Java classes for Accelerometer and Gyroscope and name the class as Accelerometer and Gyroscope.

Change the style to NoActionBar in the themes.xml file: 

<style name=”AppTheme” parent=”Theme.AppCompat.NoActionBar”>

Step 3: Working with the activity_main.xml file

Navigate to the app > res > layout > activity_main.xml and add the below code to that file. Below is the code for the activity_main.xml file. 



XML




<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
  
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="GeeksforGeeks"
        android:textColor="#0F9D58"
        android:textSize="42dp"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
  
</androidx.constraintlayout.widget.ConstraintLayout>

Step 4: Working with the Accelerometer.java file

In the Accelerometer.java file, we will create functions to get the device’s coordinates in the X, Y, and Z-axis. The function will send the required parameters to the Sensor and will get the coordinates in the return value. We will first create SensorManager, Sensor, and SensorEventListener objects. SensorManager and Sensor variables allow us to access the device’s sensors whereas SensorEventListener is called every time the device’s position changes and sensors are engaged. Below is the code for the Accelerometer.java file. Comments are added inside the code to understand the code in more detail.

Java




import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
  
public class Accelerometer {
  
    // create an interface with one method
    public interface Listener {
        // create method with all 3
        // axis translation as argument
        void onTranslation(float tx, float ty, float ts);
    }
  
    // create an instance
    private Listener listener;
  
    // method to set the instance
    public void setListener(Listener l) {
        listener = l;
    }
  
    private SensorManager sensorManager;
    private Sensor sensor;
    private SensorEventListener sensorEventListener;
  
    // create constructor with 
    // context as argument
    Accelerometer(Context context) {
        // create instance of sensor manager
        sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
          
        // create instance of sensor 
        // with type linear acceleration
        sensor = sensorManager.getDefaultSensor(Sensor.TYPE_LINEAR_ACCELERATION);
          
        // create the sensor listener
        sensorEventListener = new SensorEventListener() {
            // this method is called when the
            // device's position changes
            @Override
            public void onSensorChanged(SensorEvent sensorEvent) {
                // check if listener is 
                // different from null
                if (listener != null) {
                    // pass the three floats in listener on translation of axis
                    listener.onTranslation(sensorEvent.values[0], sensorEvent.values[1], sensorEvent.values[2]);
                }
            }
  
            @Override
            public void onAccuracyChanged(Sensor sensor, int i) {
  
            }
        };
    }
  
    // create register method 
    // for sensor notifications
    public void register() {
        // call sensor manger's register listener 
        // and pass the required arguments
        sensorManager.registerListener(sensorEventListener, sensor, SensorManager.SENSOR_DELAY_NORMAL);
    }
  
    // create method to unregister
    // from sensor notifications
    public void unregister() {
        // call sensor manger's unregister listener
        // and pass the required arguments
        sensorManager.unregisterListener(sensorEventListener);
    }
}

Step 4: Working with the Gyroscope.java file

In the Gyroscope.java file, everything will be the same except the sensor will be of type gyroscope and not accelerometer. Also, the listener will be on rotation instead of translation. Below is the code for the Gyroscope.java file. Comments are added inside the code to understand the code in more detail.

Java




import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
  
public class Gyroscope {
  
    // create an interface with one method
    public interface Listener {
        // create method with all 3
        // axis translation as argument
        void onRotation(float tx, float ty, float ts);
    }
  
    // create an instance
    private Listener listener;
  
    // method to set the instance
    public void setListener(Listener l) {
        listener = l;
    }
  
    private SensorManager sensorManager;
    private Sensor sensor;
    private SensorEventListener sensorEventListener;
  
    // create constructor with context as argument
    Gyroscope(Context context) {
          
        // create instance of sensor manager
        sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
  
        // create instance of sensor with type gyroscope
        sensor = sensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE);
  
        // create the sensor listener
        sensorEventListener = new SensorEventListener() {
  
            // this method is called when
            // the device's position changes
            @Override
            public void onSensorChanged(SensorEvent sensorEvent) {
                // check if listener is different from null
                if (listener != null) {
                    // pass the three floats in listener on rotation of axis
                    listener.onRotation(sensorEvent.values[0], sensorEvent.values[1], sensorEvent.values[2]);
                }
            }
  
            @Override
            public void onAccuracyChanged(Sensor sensor, int i) {
  
            }
        };
    }
  
    // create register method
    // for sensor notifications
    public void register() {
        // call sensor manger's register listener and pass the required arguments
        sensorManager.registerListener(sensorEventListener, sensor, SensorManager.SENSOR_DELAY_NORMAL);
    }
  
    // create method to unregister
    // from sensor notifications
    public void unregister() {
        // call sensor manger's unregister listener
        // and pass the required arguments
        sensorManager.unregisterListener(sensorEventListener);
    }
}

Step 5: Working with the MainActivity.java file

In the MainActivity.java file, we will create listener functions of both classes. We will set the background color of the screen on the device’s rotation or movement. Below is the code for the MainActivity.java file. Comments are added inside the code to understand the code in more detail.

Java




import android.graphics.Color;
import android.os.Bundle;
  
import androidx.appcompat.app.AppCompatActivity;
  
public class MainActivity extends AppCompatActivity {
  
    // create variables of the two class
    private Accelerometer accelerometer;
    private Gyroscope gyroscope;
  
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
         
        // instantiate them with this as context
        accelerometer = new Accelerometer(this);
        gyroscope = new Gyroscope(this);
          
        // create a listener for accelerometer
        accelerometer.setListener(new Accelerometer.Listener() {
            //on translation method of accelerometer
            @Override
            public void onTranslation(float tx, float ty, float ts) {
                // set the color red if the device moves in positive x axis
                if (tx > 1.0f) {
                    getWindow().getDecorView().setBackgroundColor(Color.RED);
                }
                // set the color blue if the device moves in negative x axis
                else if (tx < -1.0f) {
                    getWindow().getDecorView().setBackgroundColor(Color.BLUE);
                }
            }
        });
  
        // create a listener for gyroscope
        gyroscope.setListener(new Gyroscope.Listener() {
            // on rotation method of gyroscope
            @Override
            public void onRotation(float rx, float ry, float rz) {
                // set the color green if the device rotates on positive z axis
                if (rz > 1.0f) {
                    getWindow().getDecorView().setBackgroundColor(Color.GREEN);
                }
                // set the color yellow if the device rotates on positive z axis
                else if (rz < -1.0f) {
                    getWindow().getDecorView().setBackgroundColor(Color.YELLOW);
                }
            }
        });
    }
  
    // create on resume method
    @Override
    protected void onResume() {
        super.onResume();
  
        // this will send notification to 
        // both the sensors to register
        accelerometer.register();
        gyroscope.register();
    }
  
    // create on pause method
    @Override
    protected void onPause() {
        super.onPause();
  
        // this will send notification in 
        // both the sensors to unregister
        accelerometer.unregister();
        gyroscope.unregister();
    }
}

Output:

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