Android蓝牙`InputStream`不接收数据

Question

我有一个Raspberry Pi，我用它来读取一些传感器数据，然后尝试通过蓝牙RFCOMM插槽将数据发送到Android手机。我可以毫无问题地将数据从Android手机发送到Raspberry Pi但由于某些原因我无法通过Raspberry Pi发送的Android手机读取传感器数据。

Raspberry Pi上的write函数总是返回已发送的正确字节数，在Android端我有一个线程读取InputStream并且有一个available函数来检查是否有任何字节要读，但它几乎每次都不返回任何内容。但是，它有时读取（可能是20次）传感器数据，并且在消息处理程序将数据传递回另一个活动并在文本视图上打印数据之后，程序崩溃。

即使Raspberry Pi发送数据，也许有人可以解释为什么InputStream没有收到任何数据。非常感谢提前！

这是我的BluetoothTransferThread类：

public class BluetoothTransferThread extends Thread {

private final BluetoothSocket connectedSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
private Context context;
private final Handler threadHandler;

public BluetoothTransferThread(BluetoothSocket socket, Context context, Handler mHandler) {
    this.context = context;
    connectedSocket = socket;
    threadHandler = mHandler;
    InputStream tmpIn = null;
    OutputStream tmpOut = null;

    // Get the BluetoothSocket input and output streams
    try {
        tmpIn = socket.getInputStream();
        tmpOut = socket.getOutputStream();
    } catch (IOException e) {

    }

    mmInStream = tmpIn;
    mmOutStream = tmpOut;
}

public void run() {

    //Send a transfer thread created message to activity
    threadHandler.obtainMessage(BluetoothClientActivity.TRANSFER_THREAD_CREATED).sendToTarget();

    int[] buffer;
    int readByte;
    int i = 0, bytesAvailable;

    /**
     * Keep listening to the InputStream while connected
     */
    while (true) {

        try {

            //Check if there is bytes available to read in the InputStream
            bytesAvailable = mmInStream.available();
            if(bytesAvailable > 0) {
                buffer = new int[bytesAvailable];
                Log.d(getClass().getName(), String.format("value = %d", bytesAvailable));

                /*
                 * Read the stream byte at a time and store it to a buffer until we have received the end of the frame char
                 */
                do {
                    //readByte = dInputStream.readUnsignedByte();
                    readByte = mmInStream.read();
                    buffer[i] = readByte;
                    i++;
                } while (readByte != 0xEE);

                //Send the received data through handler back to activity
                threadHandler.obtainMessage(BluetoothClientActivity.MESSAGE_READ, buffer).sendToTarget();
            }
            try {
                currentThread().sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

/**
 * Write to the connected OutStream.
 */
public void write(byte[] buffer) {
    try {
        mmOutStream.write(buffer);
        Toast.makeText(this.context, "Wrote to the socket", Toast.LENGTH_SHORT).show();

    } catch (IOException e) {
        Toast.makeText(this.context, "Couldn't write to the socket", Toast.LENGTH_SHORT).show();
    }
}

/**
 * Close the transfer thread
 */
public void cancel() {
    try {
        connectedSocket.close();
        Toast.makeText(this.context, "Transfer thread socket closed", Toast.LENGTH_SHORT).show();
    } catch (IOException e) {
        Toast.makeText(this.context, "Couldn't close the transfer thread socket", Toast.LENGTH_SHORT).show();
    }
}

这是Raspberry Pi的侧面代码片段：

case READ_SENSOR_DATA:

            /* Serialize the data and send it through the socket */
            pthread_mutex_lock(&sensorData->mutex1);
            pthread_mutex_lock(&sensorData->mutex5);
            serializationLengthPtr = serializeStruct(sendBuffer, sensorData);
            pthread_mutex_unlock(&sensorData->mutex1);
            pthread_mutex_unlock(&sensorData->mutex5);
            sendBuffer[8] = FRAME_END_CHAR;

            bytes_sent = write(client, sendBuffer, serializationLengthPtr - sendBuffer + 1);
            if(bytes_sent <= 0) {
                perror("Write failed!\n");
                socketCloseFlag = true;
                break;
            }
            else {
                printf("Bytes sent: %d\n", bytes_sent);
            }
            break;