Question

我正在尝试在Arduino Uno上处理模拟压力传感器信号，并通过蓝牙将输出字符串发送到我的Android应用程序UI。

我已经在应用程序和HC-05模块之间建立了BT连接，并且可以通过将字符串写入到Arduino来获取UI上的inputStream，并作为响应返回一个字符串。

一旦从Arduino收到信号，我就试图触发对话框警报，将按钮b1配置为setOnclickListner以写入Arduino，并作为响应，Arduino发送inputStream。

问题是应用程序在活动打开后立即读取输入流，但此后停止接收，这对我来说是个问题，因为我的UI的设计假定基于来自实时输入数据的信号发送信号传感器，而不是何时由setOnClickListener触发。

我试图找到一种无需单击按钮即可写入Arduino的方法，然后一旦应用程序读取了输入流，我就需要它继续监听传入的数据并每次都调用对话框函数，在我可以开始？

public class Bluetooth_Activity extends AppCompatActivity   {

    //widgets
    Button b1;  Button b2; Button b3;
    TextView t1; TextView t2;

//    Bluetooth:
    String address = null, name = null;
    BluetoothAdapter myBluetooth = null;
    BluetoothServerSocket serverSocket;
    BluetoothSocket btSocket = null;
    Set<BluetoothDevice> pairedDevices;
    static final UUID myUUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
    Handler bluetoothIn;
    BluetoothDevice dispositivo;
    private StringBuilder recDataString = new StringBuilder();
    InputStream tmpIn = null;
    OutputStream tmpOut = null;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_bluetooth_);
        b1 = (Button) findViewById(R.id.button1);
        b3 = (Button) findViewById(R.id.str_dialog);

        try {
            bluetooth_connect_device();

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

private void alertSystem () throws IOException {
    AlertDialog.Builder mBuilder = new AlertDialog.Builder(Bluetooth_Activity.this);
    View mView = getLayoutInflater().inflate(R.layout.alert_dialog, null);
    Button mClose = (Button) mView.findViewById(R.id.btn_close);

    mBuilder.setView(mView);
    final AlertDialog dialog = mBuilder.create();
    dialog.show();

    mClose.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            dialog.dismiss();
        }
    });
}


//  BLUETOOTH FUNCTIONS:
    private class someThread extends Thread{
        public void run() {
            abc();
        }
    }


    private void bluetooth_connect_device() throws IOException {

        try {
            myBluetooth = BluetoothAdapter.getDefaultAdapter();
            address = myBluetooth.getAddress();
            pairedDevices = myBluetooth.getBondedDevices();
            if (pairedDevices.size() > 0) {
                for (BluetoothDevice bt : pairedDevices) {
                    address = bt.getAddress().toString();
                    name = bt.getName().toString();
                    Toast.makeText(getApplicationContext(), "Connected", Toast.LENGTH_SHORT).show();
                }
            }

        } catch (Exception we) {
        }
        myBluetooth = BluetoothAdapter.getDefaultAdapter();//get the mobile bluetooth device
        BluetoothDevice dispositivo = myBluetooth.getRemoteDevice(address);//connects to the device's address and checks if it's available
        btSocket = dispositivo.createInsecureRfcommSocketToServiceRecord(myUUID);//create a RFCOMM (SPP) connection
        btSocket.connect();

        try
        {
            Toast.makeText(getApplicationContext(), ("BT Name: " + name + "\nBT Address: " + address), Toast.LENGTH_SHORT).show();
        } catch (Exception e) {}

    }

    public void abc() {

            try {

                byte[] buffer = new byte[256];  // buffer store for the stream
                int bytes; // bytes returned from read()

                tmpIn = btSocket.getInputStream();
                DataInputStream mmInStream = new DataInputStream(tmpIn);
                bytes = mmInStream.read(buffer);
                String readMessage = new String(buffer, 0, bytes);
                Toast.makeText(getApplicationContext(),
                        "OutPut Recived From Bluetooth : \n" + readMessage,
                        Toast.LENGTH_SHORT).show();
                alertSystem();
            } catch (Exception e) {
            }
       }

      @Override
      public void onClick(View v) {
        if (v.getId() == R.id.button1)
        {
            try
            {
                String i="f";         //here i'm sending a single char f and when arduino recived it it will
                // send a response 
                btSocket.getOutputStream().write(i.getBytes());
                Thread.sleep(1500);
                abc();
            } catch (Exception e) {}


        }   
        }

Answer 1

很清楚为什么会这样，因为您是用这种方式编码的！您将执行Bluetooth io的代码片段放在onclick侦听器中，因此只有在单击该按钮时才能运行该代码；

如果您希望在收到某个蓝牙信号后限制android应用执行一段代码，则需要在另一个thread中无限期地监听该信号（并且不要阻塞ui）。（不仅是单击按钮时），如果要更新用户界面，请调用handler；因此您的代码应如下所示：

new Thread(new Runnable() {
        @Override
        public void run() {
            while (true){//an infinite loop
                //read signals
                //process them
                //call some handler to deal with the ui
            }
        }
    })

Android-Arduino蓝牙通信：应用程序停止读取输入流

1 个答案: