Android蓝牙串口通信源码解析与实现 文章

随着物联网技术的不断发展，蓝牙通信技术在嵌入式设备中的应用越来越广泛。在Android开发中，蓝牙串口通信是连接移动设备与外部设备的重要方式之一。本文将深入解析Android蓝牙串口通信的源码，帮助开发者更好地理解和实现蓝牙串口通信功能。

一、蓝牙串口通信概述

蓝牙串口通信是指通过蓝牙技术将移动设备与外部设备进行串口通信。在Android系统中，蓝牙串口通信主要依赖于蓝牙SPP（Serial Port Profile）协议实现。SPP协议是一种串行通信协议，允许两个设备之间进行全双工通信。

二、Android蓝牙串口通信源码解析

1.请求蓝牙设备权限

在Android 6.0及以上版本，需要动态请求蓝牙设备权限。以下是一个示例代码：

java if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { if (ContextCompat.checkSelfPermission(this, Manifest.permission.BLUETOOTH) != PackageManager.PERMISSION_GRANTED) { ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.BLUETOOTH}, 1); } }

2.初始化BluetoothAdapter

java BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); if (bluetoothAdapter == null) { // 没有蓝牙硬件 return; }

3.扫描蓝牙设备

java BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); BluetoothDevice device = bluetoothAdapter.getRemoteDevice(deviceAddress); BluetoothSocket socket = device.createRfcommSocketToServiceRecord(UUID.fromString(SPP_UUID)); socket.connect();

4.发送数据

java OutputStream outputStream = socket.getOutputStream(); byte[] bytes = "Hello, Bluetooth!".getBytes(); outputStream.write(bytes); outputStream.flush();

5.接收数据

java InputStream inputStream = socket.getInputStream(); byte[] buffer = new byte[1024]; int bytesRead = inputStream.read(buffer); String receivedData = new String(buffer, 0, bytesRead);

6.关闭连接

java socket.close();

三、蓝牙串口通信实现

1.创建一个Service

在AndroidManifest.xml中声明一个Service：

xml <service android:name=".BluetoothService" />

在BluetoothService中实现以下方法：

`java public class BluetoothService extends Service { private BluetoothSocket socket; private InputStream inputStream; private OutputStream outputStream;

@Override
public IBinder onBind(Intent intent) {
    return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    // 获取连接的设备
    BluetoothDevice device = intent.getParcelableExtra("device");
    // 创建连接
    try {
        socket = device.createRfcommSocketToServiceRecord(UUID.fromString(SPP_UUID));
        socket.connect();
        inputStream = socket.getInputStream();
        outputStream = socket.getOutputStream();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return START_STICKY;
}
@Override
public void onDestroy() {
    super.onDestroy();
    if (socket != null) {
        try {
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
// 发送数据
public void sendData(String data) {
    try {
        byte[] bytes = data.getBytes();
        outputStream.write(bytes);
        outputStream.flush();
    } catch (IOException e) {
        e.printStackTrace();
    }
}
// 接收数据
public String receiveData() {
    try {
        byte[] buffer = new byte[1024];
        int bytesRead = inputStream.read(buffer);
        return new String(buffer, 0, bytesRead);
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    }
}

} `

2.在Activity中绑定Service

`java public class MainActivity extends AppCompatActivity { private BluetoothService bluetoothService;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Intent intent = new Intent(this, BluetoothService.class);
    bindService(intent, serviceConnection, BIND_AUTO_CREATE);
}
private ServiceConnection serviceConnection = new ServiceConnection() {
    @Override
    public void onServiceConnected(ComponentName name, IBinder binder) {
        BluetoothService.BluetoothBinder binder = (BluetoothService.BluetoothBinder) binder;
        bluetoothService = binder.getService();
    }
    @Override
    public void onServiceDisconnected(ComponentName name) {
        bluetoothService = null;
    }
};
// 发送数据
public void sendData(String data) {
    if (bluetoothService != null) {
        bluetoothService.sendData(data);
    }
}
// 接收数据
public String receiveData() {
    if (bluetoothService != null) {
        return bluetoothService.receiveData();
    }
    return null;
}

} `

四、总结

本文对Android蓝牙串口通信源码进行了详细解析，并给出了一个简单的实现示例。在实际开发过程中，开发者可以根据具体需求进行修改和完善。希望本文能对广大开发者有所帮助。