Introduction

Android is one of the most popular operating systems for mobile. In this article, I will show you how to create Bluetooth Android applications using Android Studio.

Requirements

Steps to be followed

Follow these steps to create a Bluetooth Android application. I have included the source code in the attachment.

Step 1. Open Android Studio and start a new Android Studio Project.

Android

Step 2. You can choose your application name and choose where your project is to be stored. If you wish to use C++ for coding the project, mark the "Include C++ support", and click the "Next" button.

Next

Now, select the version of Android and select the target Android devices.

Android devices

Step 3. Now, add the activity and click the "Next" button.

Activity

Add the activity name and click "Finish".

Finish

Step 4. Go to activity_main.xml. This XML file contains the design code for your Android app.

XML file

The XML code is given below.

<?xml version="1.0" encoding="utf-8"?>  
<android.support.constraint.ConstraintLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"  
    xmlns:app="http://schemas.android.com/apk/res-auto"  
    xmlns:tools="http://schemas.android.com/tools"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    tools:context="abu.bluetooth.MainActivity" >  
    <RelativeLayout  
        android:layout_width="match_parent"  
        android:layout_height="wrap_content"  
        android:orientation="vertical">   
        <TextView  
            android:text=""  
            android:id="@+id/out"  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content" />
        <Button  
            android:id="@+id/button1"  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"  
            android:layout_alignParentLeft="true"  
            android:layout_alignParentTop="true"  
            android:layout_marginLeft="30dp"  
            android:layout_marginTop="49dp"  
            android:text="ON" />
        <Button  
            android:id="@+id/button2"  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"  
            android:layout_alignLeft="@+id/button1"  
            android:layout_below="@+id/button1"  
            android:layout_marginTop="27dp"  
            android:text="COVERAGE" />
        <Button  
            android:id="@+id/button3"  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"  
            android:layout_alignLeft="@+id/button2"  
            android:layout_below="@+id/button2"  
            android:layout_marginTop="28dp"  
            android:text="OFF" />  
    </RelativeLayout>  
</android.support.constraint.ConstraintLayout>

Step 5. Go to Main Activity.java. This Java program is the backend language for your app.

Java program

The Java code is given below.

package abu.bluetooth;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.bluetooth.BluetoothAdapter;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
    private static final int REQUEST_ENABLE_BT = 0;
    private static final int REQUEST_DISCOVERABLE_BT = 0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final TextView out = findViewById(R.id.out);
        final Button button1 = findViewById(R.id.button1);
        final Button button2 = findViewById(R.id.button2);
        final Button button3 = findViewById(R.id.button3);
        final BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        if (mBluetoothAdapter == null) {
            out.append("device not supported");
        }
        button1.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                if (!mBluetoothAdapter.isEnabled()) {
                    Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                    startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
                }
            }
        });
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                if (!mBluetoothAdapter.isDiscovering()) {
                    Context context = getApplicationContext();
                    CharSequence text = "MAKING YOUR DEVICE DISCOVERABLE";
                    int duration = Toast.LENGTH_SHORT;
                    Toast toast = Toast.makeText(context, text, duration);
                    toast.show();
                    Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
                    startActivityForResult(enableBtIntent, REQUEST_DISCOVERABLE_BT);
                }
            }
        });
        button3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                mBluetoothAdapter.disable();
                Context context = getApplicationContext();
                CharSequence text = "TURNING_OFF BLUETOOTH";
                int duration = Toast.LENGTH_LONG;
                Toast toast = Toast.makeText(context, text, duration);
                toast.show();
            }
        });
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}

Step 6. We need to make a Bluetooth request. So, add the Bluetooth permission in AndroidManifest.xml.

Bluetooth Permission

The AndroidManifest.xml code is given below.

<?xml version="1.0" encoding="utf-8"?>  
<manifest xmlns:android="http://schemas.android.com/apk/res/android"  
    package="abu.bluetooth">  
    <uses-permission android:name="android.permission.BLUETOOTH" />  
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />  
    <application  
        android:allowBackup="true"  
        android:icon="@mipmap/ic_launcher"  
        android:label="@string/app_name"  
        android:roundIcon="@mipmap/ic_launcher_round"  
        android:supportsRtl="true"  
        android:theme="@style/AppTheme">  
        <activity android:name=".MainActivity">  
            <intent-filter>  
                <action android:name="android.intent.action.MAIN" />  
                <category android:name="android.intent.category.LAUNCHER" />  
            </intent-filter>  
        </activity> 
    </application>  
</manifest>

Step 7. Now, go to the menu bar and click "Make Project" or press ctrl+f9 to debug the app from errors.

Make Project

Step 8. Then, click the "Run" button or press shift+f10 to finally run the project. And, choose the "virtual machine" option and click OK.

virtual Machine

Conclusion

We have successfully created a Bluetooth Android application using Android Studio.

Android application

Allow

Coverage