Question

我正在编写一个可以与arduino交互的Android应用程序。我的应用程序有2个按钮1.连接2.断开连接，启动和停止蓝牙服务。我在arduino上有一个测试草图，当收到“1”时会发送“404”（只是为了测试！）回到我的手机。

这是我的蓝牙服务类

    public class BluetoothService extends Service {
        private BluetoothManager bluetoothManager;
        private ServiceHandler mSHandler;

        public BluetoothService(){}

        private final class ServiceHandler extends Handler {
            public ServiceHandler(Looper looper) {
                super(looper);
            }

            @Override
            public void handleMessage(Message msg) {
            }
        }

        @Override
        public void onCreate() {
            super.onCreate();
            HandlerThread thread = new HandlerThread("ServiceStartArguments", android.os.Process.THREAD_PRIORITY_BACKGROUND);
            thread.start();
            Looper mSLoop = thread.getLooper();
            mSHandler = new ServiceHandler(mSLoop);
        }

        @Override
        public int onStartCommand(Intent intent, int flags, int startId) {
            Message msg = mSHandler.obtainMessage();
            msg.arg1 = startId;
            mSHandler.sendMessage(msg);
            bluetoothManager=new BluetoothManager();
            bluetoothManager.writeData("1", getApplicationContext());  //sending "1" to arduino
            String str= bluetoothManager.readData(getApplicationContext());  //reading "404" from arduino
            Toast.makeText(getApplicationContext(), str, Toast.LENGTH_LONG).show();
            return START_STICKY;
        }


        @Override
        public void onDestroy(){
            bluetoothManager.turnBluetoothOff();
        }

        @Override
        public IBinder onBind(Intent intent) {
        return null;
        }
    }

现在这是我的BluetoothManager课程：

public class BluetoothManager {
    private BluetoothAdapter bluetoothAdapter;
    private BluetoothDevice bluetoothDevice;
    private BluetoothSocket bluetoothSocket;
    private ConnectedThread connectedThread;
    private byte[] buffer;

    public BluetoothManager(){
        buffer=new byte[256];
        bluetoothSocket=null;
        bluetoothAdapter=null;
        bluetoothDevice=null;
        connectedThread=null;
        getBluetoothAdapter();
        if(!isBluetoothAvailable()){
            turnBluetoothOn();
        }
        scanToConnect();
    }
    public void turnBluetoothOff(){
        try {
            bluetoothSocket.close();
            bluetoothSocket=null;
            bluetoothAdapter.cancelDiscovery();
            bluetoothAdapter.disable();
            bluetoothAdapter=null;
            bluetoothDevice=null;
        }catch(Exception e){
            e.printStackTrace();
        }
    }
    private boolean isBluetoothAvailable(){
        return bluetoothAdapter.isEnabled();
    }
    private void turnBluetoothOn(){
        bluetoothAdapter.enable();
    }
    public String readData(Context context){
        String outputString=null;
        if(isBluetoothAvailable()) {
            outputString = connectedThread.read(buffer);
        }else{
            Toast.makeText(context, "Error: Not Connected", Toast.LENGTH_LONG).show();
        }
        return outputString;
    }
    public void writeData(String string, Context context){
        if(isBluetoothAvailable()) {
            connectedThread.write(string.getBytes());
        }else{
            Toast.makeText(context, "Error: Not Connected", Toast.LENGTH_LONG).show();
        }
    }
    private void getBluetoothAdapter(){
        try{
            bluetoothAdapter=BluetoothAdapter.getDefaultAdapter();
        }catch (Exception e){
            e.printStackTrace();
        }
    }
    private void scanToConnect(){
        Set<BluetoothDevice> pairedDevices=bluetoothAdapter.getBondedDevices();
        if(pairedDevices.size()>0){
            try {
                for (BluetoothDevice device : pairedDevices) {
                    if (device.getName().equals("HC-05")) {
                        bluetoothDevice = device;
                        new connectBt(bluetoothDevice);
                        break;
                    }
                }
            }catch(Exception e){
                e.printStackTrace();
            }
        }
    }
    private class connectBt extends Thread {
        public connectBt(BluetoothDevice device) {
            BluetoothSocket tmp = null;
            bluetoothDevice = device;
            UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");
            try {
                tmp = device.createRfcommSocketToServiceRecord(uuid);
            } catch (IOException e) {
                e.printStackTrace();
            }
            bluetoothSocket = tmp;
            run();
        }
        public void run() {
            bluetoothAdapter.cancelDiscovery();
            try {
                bluetoothSocket.connect();
                connectedThread = new ConnectedThread(bluetoothSocket);
            } catch (IOException connectException) {
                closeSocket();
            }
        }
        private void closeSocket() {
            try {
                bluetoothSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    private class ConnectedThread extends Thread{
        private InputStream mInput=null;
        private OutputStream mOutput=null;
        private String strInput;

        public ConnectedThread(BluetoothSocket socket){
            bluetoothSocket=socket;
            InputStream tmpIn=null;
            OutputStream tmpOut=null;
            try{
                tmpIn=socket.getInputStream();
                tmpOut=socket.getOutputStream();
            }catch(IOException e){
                e.printStackTrace();
                closeSocket();
            }
            mInput=tmpIn;
            mOutput=tmpOut;
        }
        public void write(byte[] bytes){
            try{
                mOutput.write(bytes);
            }catch(IOException e){
                e.printStackTrace();
            }
        }
        public String read(byte[] bytes){
            try {
                mInput.read(bytes);
                strInput = new String(bytes);
            }catch(Exception e){
                e.printStackTrace();
            }
            return strInput;
        }
        public void closeSocket(){
            try{
                bluetoothSocket.close();
            }catch(IOException e){
                e.printStackTrace();
            }
        }
    }
}

我的问题是我必须按两次连接按钮连接到arduino，首先按下将启用蓝牙，第二次按下将连接到arduino，然后发送和接收数据。但这不是我想要的，启用蓝牙和连接应该只需一次按下即可。那么为什么这样呢？

N.B：我是java和android的新手。

Answer 1

启用蓝牙后，需要一段时间才能获得配对设备列表。但在这种情况下，您在打开蓝牙后立即阅读配对设备。可能是你延迟了连接部分。

使用处理程序方法延迟执行。

Answer 2

您可以使用意图过滤器来收听ACTION_ACL_CONNECTED，ACTION_ACL_DISCONNECT_REQUESTED和ACTION_ACL_DISCONNECTED广播：

了解更多请查看此内容;

How to programmatically tell if a Bluetooth device is connected? (Android 2.2)

Android-蓝牙：蓝牙服务意外行为

2 个答案: