我试图在我的Android手机(目标4.3)上显示从传输arduino类型设备接收的传感器数据 . 传输通过蓝牙进行 . 我能够连接到arduino类型的设备,甚至共享数据,但由于某种原因我有同步问题 .
现在设置arduino的方式,在成功连接之后它等待从我的电话接收一个字节(无符号字节值255),当它接收到该字节时,它通过发送包含来自三个信息的数据包(3个字节)来响应不同的传感器即
packet:
byte 1: temperature data
byte 2: cadence data
byte 3: speed data
我所要做的就是重复显示这些数据(现场更新),直到用户终止Android手机上的连接 .
这是我的代码,我觉得我在逻辑中的某处发生了一个小错误 .
MessageHandler
Handler mHandler = new Handler(){
public void handleMessage(Message msg){
super.handleMessage(msg);
switch(msg.what){
case SUCCESS_CONNECT:
// Do Something;
ConnectedThread connectedThread = new ConnectedThread((BluetoothSocket)msg.obj);
Toast.makeText(getActivity(),"CONNECTED",Toast.LENGTH_SHORT).show();
/*
* Could send test string here
*/
/*
* String connect_string = "test";
* connectedThread.write(connect_string.getBytes());
*/
connectedThread.start();
break;
case MESSAGE_READ:
byte[] readBuf = (byte[])msg.obj;
int tempInt = byteToInt(readBuf[0]);
int cadenceInt = byteToInt(readBuf[1]);
int speedInt = byteToInt(readBuf[2]);
EditText temperatureData = (EditText)getActivity().findViewById(R.id.temperatureData);
temperatureData.setText(Integer.toString(tempInt));
EditText cadenceData = (EditText)getActivity().findViewById(R.id.cadence);
cadenceData.setText(Integer.toString(cadenceInt));
EditText speedData = (EditText)getActivity().findViewById(R.id.speed_data);
speedData.setText(Integer.toString(speedInt));
}
}
};
ConnectThread
public class ConnectThread extends Thread {
private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {
/*
* Use a temporary object that is later assigned to mmSocket,
* because mmSocket is final
*/
BluetoothSocket tmp = null;
mmDevice = device;
// Get a BluetoothSocket to connect with the given BluetoothDevice
try {
// MY_UUID is the app's UUID string, also used by the server code
tmp = device.createRfcommSocketToServiceRecord(MY_UUID);
} catch (IOException e) { }
mmSocket = tmp;
}
public void run() {
// Cancel discovery because it will slow down the connection
mBluetoothAdapter.cancelDiscovery();
try {
// Connect the device through the socket. This will block
// until it succeeds or throws an exception
mmSocket.connect();
} catch (IOException connectException) {
// Unable to connect; close the socket and get out
try {
mmSocket.close();
} catch (IOException closeException) {
Toast.makeText(getActivity(), "Connecting to device failed!", Toast.LENGTH_LONG).show();
}
return;
}
// Do work to manage the connection (in a separate thread)
mHandler.obtainMessage(SUCCESS_CONNECT, mmSocket).sendToTarget();
}
/** Will cancel an in-progress connection, and close the socket */
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) { }
}
}
ConnectedThread
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the input and output streams, using temp objects because
// member streams are final
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) { }
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
byte[] buffer; // 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
buffer = new byte[3];
byte maxByte = (byte) 1;
mmOutStream.write(255);
bytes = mmInStream.read(buffer,0,buffer.length);
// Send the obtained bytes to the message handler
mHandler.obtainMessage(MESSAGE_READ,buffer).sendToTarget();
}
catch (IOException e) {
break;
}
}
}
/* Call this from the main activity to send data to the remote device */
public void write(byte[] bytes) {
try {
mmOutStream.write(bytes);
} catch (IOException e) { }
}
}
Byte To Int方法
public static int byteToInt(byte b){
int value;
value = b & 0xFF;
return value;
}
我收到的数据正在显示但通常最终错误,主要是因为字节数组序列关闭导致显示错误的值 . 我一直试图弄清楚这一点,任何输入都会有所帮助 .
1 回答
检查是否可以将消息发送给处理程序克隆数组 . 它应该类似于“buffer.clone”或“buffer.clone()”而不是简单的“缓冲区” . 如果是这样,则意味着将未克隆的缓冲区复制为对处理程序的引用 . 当处理程序正在执行其操作时,连接的线程可以重新定义数组并将其重新分配给它不同的值 . 要对此进行测试,您还可以定义缓冲区广告Byte []而不是byte [] . 这样我修复了我的应用程序中的类似问题 .