如何在android中接收完整的arduino字符串

Question

我正在为我的 arduino 传感器做一个应用程序，我想知道如何通过蓝牙实际从 arduino 获取数据到 android studio，因为在我的 arduino 中我输入了Serial.println("occupied")，但是当在 android 中接收时它以某种方式与一些数字混合/像“o2cuppied”这样的字节，否则它将在logcat中单独接收。不知道有什么问题。

Arduino 代码：

void setup() {
  serial1.begin(9600); //for the bluetooth module
}
void loop() {
 
  //send data to Bluetooth module//
  if (dist[0] < dist_threshold) {
    serial1.print("Occupied\n");
   
  }
 if (dist[1] < dist_threshold) {
    
    serial1.print("Occupied2\n");
    
  }

安卓

 @Override
    protected void onCreate(Bundle savedInstanceState) {
 h = new Handler() {
            public void handleMessage(android.os.Message msg) {

                switch (msg.what) {
                    case RECEIVE_MESSAGE:                             // if receive massage
                        byte[] readBuf = (byte[]) msg.obj;
                        String strIncom = new String(readBuf, 0, msg.arg1);   // create string from bytes array
                                                     // and clear
                            txtArduino.setText("Data from Arduino: " + strIncom);

                            break;
                }
            }
        };
}

private class ConnectedThread extends Thread {
        private final BluetoothSocket bluetoothSocket;
        private final InputStream mmInStream;
        private final OutputStream mmOutStream;

        public ConnectedThread(BluetoothSocket socket) {
            InputStream tmpIn = null;
            OutputStream tmpOut = null;
            bluetoothSocket = socket;

            // Get the input and output streams, using temp objects because
            // member streams are final
            try {
                tmpIn = socket.getInputStream();
                tmpOut = socket.getOutputStream();
            } catch (IOException e) {
                e.printStackTrace();
            }

            mmInStream = tmpIn;
            mmOutStream = tmpOut;
        }

        public void run() {
            byte[] buffer = new byte[1024];  // buffer store for the stream
            int bytes; // bytes returned from read()

            // Keep listening to the InputStream until an exception occurs
            while (true) {
                try {
                    // Read from the InputStream
                    bytes = mmInStream.read(buffer);        // Get number of bytes and message in "buffer"
                    String incomingMessage = new String(buffer, 0, bytes);
                    Log.d(TAG, "InputStream: " + incomingMessage);
                    h.obtainMessage(RECEIVE_MESSAGE, bytes, -1, buffer).sendToTarget(); // Send to message queue Handler
                   
                } catch (IOException e) {
                    Log.e(TAG, "write: Error reading Input Stream. " + e.getMessage() );
                    break;
                }
            }
        }
    }

Logcat

2019-11-27 12:28:13.505 12733-12893/com.example.fyp D/MainActivity: InputStream: O

2019-11-27 12:28:13.508 12733-12893/com.example.fyp D/MainActivity: InputStream: ccupied

Answer 1

private StringBuilder sb = new StringBuilder();

                byte[] readBuf = (byte[]) msg.obj;
                String strIncom = new String(readBuf, 0, msg.arg1); // create string from bytes array
                sb.append(strIncom);                                      // append string
                int endOfLineIndex = sb.indexOf("\r\n");                  // determine the end-of-line
                if (endOfLineIndex > 0) {                                 // if end-of-line,
                    sbprint = sb.substring(0, endOfLineIndex);            // extract string
                    sb.delete(0, sb.length());
                    final String finalSbprint = sbprint;

Answer 2

TCP：您必须连接传入的字节。

但如果 Arduino 只发送文本，您可以让它发送“Occupied\n”而不是“Occupied”，让您的生活更轻松。

在接收端添加一个 BufferedStreamReader 并使用它的 readLine() 成员读取该行。