Android基于蓝牙串口编程实现HC-05通讯
最近接了个工程自动化的项目，需求是实时接收从单片机传过来的数据，并进行数据分析处理再进行显示，在查阅大量的相关博客和自己踩了不少的坑后，想说把自己的一些经验分享出来给后来人做个参考www
先介绍下蓝牙串口的定义
蓝牙串口是基于SPP协议（Serial Port Profile），能在蓝牙设备之间创建串口进行数据传输的一种设备。蓝牙串口的目的是针对如何在两个不同设备（通信的两端）上的应用之间保证一条完整的通信路径。
目前应用商店可以下载到的蓝牙串口app就是基于SPP协议，而有一些蓝牙搜索app搜索不到HC-05就是由于没有实现蓝牙串口服务。要想要在自己的app内实现SPP协议需要服务对应的UUID，蓝牙串口服务的UUID为：
SerialPortServiceClass_UUID = '{00001101-0000-1000-8000-00805F9B34FB}'
更多的手机蓝牙各类服务对应的UUID，可以通过下面这个网站进行查询：
https://www.douban.com/group/topic/20009323/
顺便讲下蓝牙串口app的使用，首先需要在系统设置里，连接上HC-05的蓝牙，默认配对密码为1234，默认波特率为9600，默认名为HC-05。最好在连接后再看一下对应的MAC地址，因为我做的是单一连接，单片机同一时间只能接入一个蓝牙设备，所以需求对更改连接蓝牙模块需求要求不大，如果用户不在创建项目时更改设备MAC地址，则使用的就是默认的MAC地址，所以也没有做选择蓝牙设备的模块。
博客附本项目截图以及项目源码地址。
需要的权限
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<!-- 6.0以上需要加的额外权限 -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
获取蓝牙适配器
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
不支持蓝牙时
// If the adapter is null, then Bluetooth is not supported
if (mBluetoothAdapter == null) {
Toast.makeText(this, "Bluetooth is not available", Toast.LENGTH_LONG).show();
finish();
}
绑定蓝牙设备
// String MACAddr = "xx:xx:xx:xx:xx:xx";
BluetoothDevice bluetoothDevice = mBluetoothAdapter.getRemoteDevice(MACAddr);
*如果检测到蓝牙没打开，调用系统蓝牙设置（可选）
Intent intent = new Intent(Settings.ACTION_BLUETOOTH_SETTINGS);
startActivity(intent);
连接设备，开启蓝牙连接线程
public void connect(BluetoothDevice device) {
printLog("connect to: " + device);
// Start the thread to connect with the given device
mConnectThread = new ConnectThread(device);
mConnectThread.start();
}
连接线程
/**
* This thread runs while attempting to make an outgoing connection with a
* device. It runs straight through; the connection either succeeds or
* fails.
*/
private class ConnectThread extends Thread {
private final BluetoothSocket mmSocket;
private final BluetoothDevice mmDevice;
public ConnectThread(BluetoothDevice device) {
mmDevice = device;
BluetoothSocket tmp = null;
// Get a BluetoothSocket for a connection with the
// given BluetoothDevice
try {
tmp = device.createRfcommSocketToServiceRecord(UUID.fromString(App.SPP_UUID));
} catch (IOException e) {
printLog("create() failed" + e);
}
mmSocket = tmp;
}
public void run() {
if (Thread.interrupted())
return;
setName("ConnectThread");
// Always cancel discovery because it will slow down a connection
mBluetoothAdapter.cancelDiscovery();
// Make a connection to the BluetoothSocket
try {
// This is a blocking call and will only return on a
// successful connection or an exception
isBlueToothConnected = true;
mmSocket.connect();
} catch (IOException e) {
printLog("unable to connect() socket " + e);
handler.sendEmptyMessage(NOT_CONNECT);
isBlueToothConnected = false;
// Close the socket
try {
mmSocket.close();
} catch (IOException e2) {
printLog("unable to close() socket during connection failure" + e2);
}
return;
}
mConnectThread = null;
isBlueToothConnected = true;
// Start the connected thread
// Start the thread to manage the connection and perform
// transmissions
handler.sendEmptyMessage(CONNECT_SUCCESS);
mConnectedThread = new ConnectedThread(mmSocket);
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
printLog("close() of connect socket failed" + e);
}
}
}
数据传输线程（可读可写，需求只用读取）
**
* This thread runs during a connection with a remote device. It handles all
* incoming and outgoing transmissions.
*/
private class ConnectedThread extends Thread {
private final BluetoothSocket mmSocket;
private final InputStream mmInStream;
private final OutputStream mmOutStream;
public ConnectedThread(BluetoothSocket socket) {
printLog("create ConnectedThread");
mmSocket = socket;
InputStream tmpIn = null;
OutputStream tmpOut = null;
// Get the BluetoothSocket input and output streams
try {
tmpIn = socket.getInputStream();
tmpOut = socket.getOutputStream();
} catch (IOException e) {
printLog("temp sockets not created" + e);
}
mmInStream = tmpIn;
mmOutStream = tmpOut;
}
public void run() {
if (Thread.interrupted()) {
printLog("return");
return;
}
printLog("BEGIN mConnectedThread");
byte[] buffer = new byte[256];
int bytes;
// Keep listening to the InputStream while connected
while (true) {
synchronized (this) {
try {
// Read from the InputStream
bytes = mmInStream.read(buffer);
Message msg = new Message();
msg.what = GET_DATA;
Bundle bundle = new Bundle();
bundle.putInt("data", buffer[0]);
msg.setData(bundle);
handler.sendMessage(msg);
} catch (IOException e) {
printLog("disconnected " + e);
// handler.sendEmptyMessage(OUT_OF_CONNECTED);
break;
}
}
}
}
/**
* Write to the connected OutStream.
*
* @param buffer The bytes to write
*/
public void write(byte[] buffer) {
try {
mmOutStream.write(buffer);
} catch (IOException e) {
Log.e(TAG, "Exception during write", e);
}
}
public void cancel() {
try {
mmSocket.close();
} catch (IOException e) {
Log.e(TAG, "close() of connect socket failed", e);
}
}
}
停止蓝牙连接
private void stopBlutoothThread() {
if (mConnectThread != null) {
mConnectThread.cancel();
mConnectThread = null;
}
if (mConnectedThread != null) {
mConnectedThread.cancel();
mConnectedThread = null;
}
}
项目截图
01
02
03
源码可以在我的Github上看到
项目地址：https://github.com/WithLei/DistanceMeasure
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