安卓&蓝牙阿杜诺 [英] Android & Bluetooth & Arduino
问题描述
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，甚至可以共享数据，但是由于某种原因，我遇到了同步问题.
I am trying to display sensor data on my Android phone (target 4.3) received from a transmitting arduino type device. The transmission takes place via Bluetooth. I am able to connect to the arduino type device and even share data, however for some reason I am having synchronization issues.
arduino 现在的设置方式，成功连接后，它等待从我的手机接收一个字节(无符号字节值 255)，当它接收到这个字节时，它通过发送一个包含以下内容的数据包(3 个字节)进行响应来自三个不同传感器的信息，即
The way the arduino is setup right now, after a successful connection it waits for a byte to be received from my phone (unsigned byte value 255), when it receives this byte it responds by sending a packet (3 bytes) containing information from three different sensors i.e.
packet:
byte 1: temperature data
byte 2: cadence data
byte 3: speed data
我所要做的就是反复显示这些数据(实时更新)，直到用户终止 Android 手机上的连接.
All I have to do is display this data(which is updating live) repeatedly until the user terminates the connection on the android phone.
这是我的代码，我觉得我在逻辑中的某个地方犯了一个小错误.
Here is my code I feel I am making a minor error somewhere in my logic.
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));
}
}
};
连接线程
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) { }
}
}
连接线程
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) { }
}
}
字节转整数方法
public static int byteToInt(byte b){
int value;
value = b & 0xFF;
return value;
}
我收到的数据正在显示，但经常以错误告终，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.
The data I receive is being displayed but often ends up wrong mostly because the byte array sequence is off which causes the wrong values to be displayed. I have been trying to figure this out for a while and any input would be helpful.
推荐答案
检查您是否可以在消息中向处理程序发送一个克隆数组.它应该类似于buffer.clone"或buffer.clone()"，而不是简单的buffer".如果是这样，则意味着未克隆的缓冲区被复制为对处理程序的引用.当处理程序在做它的事情时，连接的线程可能会重新定义数组并为其重新分配不同的值.要对此进行测试，您还可以定义缓冲区 ad Byte[] 而不是 byte[].通过这种方式，我在我的应用程序中解决了类似的问题.
Check if you can send in the message to the handler a cloned array. It should be something like "buffer.clone" or "buffer.clone()" instead of simply "buffer". If it is so, it means that the not-cloned buffer is copied as reference to the handler. While the handler is doing its stuff, the connected thread may redefine the array and reassign to it different values. To test this you can also define the buffer ad Byte[] instead of byte[]. In this way I fixed similar problem in my application.
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