Android项目实战（二十六）（蓝牙连接硬件设备开发规范流程）

古人已用三冬足，年少今开万卷余。这篇文章主要讲述Android项目实战（二十六）：蓝牙连接硬件设备开发规范流程相关的知识，希望能为你提供帮助。
原文:Android项目实战（二十六）：蓝牙连接硬件设备开发规范流程前言：
最近接触蓝牙开发，主要是通过蓝牙连接获取传感器硬件设备的数据，并进行处理。
网上学习一番，现整理出一套比较标准的操作流程代码。
如果大家看得懂，将来只需要改下硬件设备的MAC码和改下对接收数据的处理即可。一切都是套路~~~

现在以一个小型项目需求来学习android蓝牙编程
需求：通过蓝牙获取硬件数据，并显示在一个随数据即时变化的动态折线图中。
实现思路：
（1）配对蓝牙设备
（2）连接蓝牙设备，根据MAC地址，代码中修改
（3）接收数据
（4）处理数据，根据硬件厂商提供给你的数据转换公式，在BluetoothService类中修改
（5）传数据给折线图，展现实时变化
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蓝牙知识了解：
（1）、MAC地址：每个设备都有全球唯一的，根据此MAC地址判断蓝牙设备
（2）、蓝牙传输数据，通常一秒钟会传输很多个包，每个包的数据情况如下：
此时，这个包有11个字节，0x55 是首码，通常通过他来判断一个包的开始
SUM是验证码，会有一套公式来计算，判断当前包是不是一个有效的完整的包
中间的即是数据，然后硬件方面会给我们一套计算公式，可以以此获取我们要的数据。
当然每个硬件的包的数据大小都是不同的，有的可能有21个字节，每个硬件的数据的计算方式也不想同

文章图片

代码实现：
一共就三部分，因为代码篇幅可能较大，不适合一段段代码讲解，直接贴出整个代码。所有的解释都在注释当中。
其中：
（1）、红色部分是需要大家根据个人硬件情况进行修改的
（2）、紫色部分是根据个人数据情况添加删除修改的。
一：MainActivity

public class MainActivity extends Activity {private BluetoothService mBluetoothService; //自定义蓝牙服务类 private BluetoothAdapter mBluetoothAdapter; private String mConnectedDeviceName = null; //连接设备的名称//默认是1,因为程序启动时首先会连接一个蓝牙 private int current_pos = 1; //hanlder消息标识 message.what public static final int MESSAGE_STATE_CHANGE = 1; // 状态改变 public static final int MESSAGE_READ = 2; // 读取数据 public static final int MESSAGE_WRITE = 3; // 给硬件传数据，暂不需要，看具体需求 public static final int MESSAGE_DEVICE_NAME = 4; // 设备名字 public static final int MESSAGE_TOAST = 5; // Toast//传感器 ,这里默认同时需要和三个硬件连接，分别设置id 1,2,3进行区分，demo中实际只用到 MAGIKARE_SENSOR_DOWN = 1 //可以根据情况自行添加删除 public static final int MAGIKARE_SENSOR_UP = 2; public static final int MAGIKARE_SENSOR_DOWN = 1; public static final int MAGIKARE_SENSOR_CENTER = 3; public static float[] m_receive_data_up; //传感器的数据 public static float[] m_receive_data_down; //传感器的数据 ,demo中我们只需要这一个，因为只有一个硬件设备， public static float[] m_receive_data_center; //传感器的数据@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //获取蓝牙适配器 mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter(); // 1、判断设备是否支持蓝牙功能 if (mBluetoothAdapter == null) { //设备不支持蓝牙功能 Toast.makeText(this, "当前设备不支持蓝牙功能！", Toast.LENGTH_SHORT).show(); return; }// 2、打开设备的蓝牙功能 if (!mBluetoothAdapter.isEnabled()) { boolean enable = mBluetoothAdapter.enable(); //返回值表示是否成功打开了蓝牙设备 if (enable) { Toast.makeText(this, "打开蓝牙功能成功！", Toast.LENGTH_SHORT).show(); } else { Toast.makeText(this, "打开蓝牙功能失败，请到‘系统设置‘中手动开启蓝牙功能！", Toast.LENGTH_SHORT).show(); return; } }// 3、创建自定义蓝牙服务对象 if (mBluetoothService == null) { mBluetoothService = new BluetoothService(MainActivity.this, mHandler); } if (mBluetoothService != null) { //根据MAC地址远程获取一个蓝牙设备，这里固定了，实际开发中，需要动态设置参数（MAC地址） BluetoothDevice sensor_down = mBluetoothAdapter.getRemoteDevice("20:16:06:15:78:76"); if (sensor_down != null) { //成功获取到远程蓝牙设备（传感器），这里默认只连接MAGIKARE_SENSOR_DOWN = 1这个设备 mBluetoothService.connect(sensor_down, MAGIKARE_SENSOR_DOWN); } }} private Handler mHandler = new Handler(new Handler.Callback() { @Override public boolean handleMessage(Message msg) { switch (msg.what){ case MESSAGE_READ: try { String str=msg.getData().getString("index"); int index=Integer.valueOf(str); switch (index) { //获取到蓝牙传输过来的数据 case MAGIKARE_SENSOR_UP: m_receive_data_up=msg.getData().getFloatArray("Data"); break; //实际只用到这个case ，因为demo只连接了一个硬件设备 case MAGIKARE_SENSOR_DOWN: m_receive_data_down=msg.getData().getFloatArray("Data"); break; case MAGIKARE_SENSOR_CENTER: m_receive_data_center=msg.getData().getFloatArray("Data"); break; } } catch (Exception e) { // TODO: handle exception } break; case MESSAGE_STATE_CHANGE: //连接状态 switch (msg.arg1) { case BluetoothService.STATE_CONNECTED: break; case BluetoothService.STATE_CONNECTING: break; case BluetoothService.STATE_LISTEN: break; case BluetoothService.STATE_NONE: break; } break; case MESSAGE_DEVICE_NAME: mConnectedDeviceName = msg.getData().getString("device_name"); Log.i("bluetooth","成功连接到:"+mConnectedDeviceName); Toast.makeText(getApplicationContext(),"成功连接到设备" + mConnectedDeviceName,Toast.LENGTH_SHORT).show(); break; case MESSAGE_TOAST: int index=msg.getData().getInt("device_id"); Toast.makeText(getApplicationContext(),msg.getData().getString("toast"), Toast.LENGTH_SHORT).show(); //当失去设备或者不能连接设备时，重新连接 Log.d("Magikare","当失去设备或者不能连接设备时，重新连接");
//重新连接硬件设备 if(mBluetoothService!=null) { switch (index) { case MAGIKARE_SENSOR_DOWN:
//根据你的硬件的MAC地址写参数，每一个硬件设备都有一个MAC地址，此方法是根据MAC地址得到蓝牙设备 BluetoothDevice sensor_down = mBluetoothAdapter.getRemoteDevice("20:16:06:15:78:76"); if (sensor_down != null) mBluetoothService.connect(sensor_down, MAGIKARE_SENSOR_DOWN); break; case MAGIKARE_SENSOR_UP: BluetoothDevice sensor_up = mBluetoothAdapter.getRemoteDevice(""); //参数写你这个设备的MAC码 if (sensor_up != null) mBluetoothService.connect(sensor_up, MAGIKARE_SENSOR_UP); break; case MAGIKARE_SENSOR_CENTER: BluetoothDevice center = mBluetoothAdapter.getRemoteDevice(""); //参数写你这个设备的MAC码 if (center != null) mBluetoothService.connect(center, MAGIKARE_SENSOR_CENTER); break; } }break; } return false; } }); public synchronized void onResume() { super.onResume(); if (mBluetoothService != null) { if (mBluetoothService.getState() == BluetoothService.STATE_NONE) { mBluetoothService.start(); } } }@Override public void onDestroy() { super.onDestroy(); if (mBluetoothService != null) mBluetoothService.stop(); }

// 硬件通过蓝牙传输的byte类型已经转换为float类型，并且通过handler传输到 m_receive_data_down[]数组中，一下操作是获取这个数据，根据个人情况使用 //获取角度 public float[] GetAngle(int index) { float[] angles=new float[3]; if(m_receive_data_up==null ||m_receive_data_down==null ) { return angles; } switch (index) { caseMAGIKARE_SENSOR_DOWN: angles[0]=m_receive_data_down[6]; angles[1]=m_receive_data_down[7]; angles[2]=m_receive_data_down[8]; break; case MAGIKARE_SENSOR_UP: angles[0]=m_receive_data_up[6]; angles[1]=m_receive_data_up[7]; angles[2]=m_receive_data_up[8]; Log.d("安卓 Up 角度",angles[0]+","+angles[1]+","+angles[2]); break; } return angles; } //获取角速度 public static float[] GetAngleSpeed(int index) {float [] anglespeed=new float[3]; if(m_receive_data_down==null) {return anglespeed; } switch (index) { case MAGIKARE_SENSOR_DOWN:anglespeed[0]=m_receive_data_down[3]; anglespeed[1]=m_receive_data_down[4]; anglespeed[2]=m_receive_data_down[5]; break; case MAGIKARE_SENSOR_UP: anglespeed[0]=m_receive_data_up[3]; anglespeed[1]=m_receive_data_up[4]; anglespeed[2]=m_receive_data_up[5]; break; } returnanglespeed; }public float[] GetQuaternion(int index) { float[] quaternion=new float[4]; if(m_receive_data_down==null) { return quaternion; } switch (index) { caseMAGIKARE_SENSOR_DOWN: quaternion[0]=m_receive_data_down[23]; quaternion[1]=m_receive_data_down[24]; quaternion[2]=m_receive_data_down[25]; quaternion[3]=m_receive_data_down[26]; Log.i("saveinfo","m_receive_data_down23"+m_receive_data_down[23]); Log.i("saveinfo","m_receive_data_down24"+m_receive_data_down[24]); Log.i("saveinfo","m_receive_data_down25"+m_receive_data_down[25]); Log.i("saveinfo","m_receive_data_down26"+m_receive_data_down[26]); break; case MAGIKARE_SENSOR_UP: quaternion[0]=m_receive_data_up[23]; quaternion[1]=m_receive_data_up[24]; quaternion[2]=m_receive_data_up[25]; quaternion[3]=m_receive_data_up[26]; break; case MAGIKARE_SENSOR_CENTER: quaternion[0]=m_receive_data_center[23]; quaternion[1]=m_receive_data_center[24]; quaternion[2]=m_receive_data_center[25]; quaternion[3]=m_receive_data_center[26]; } returnquaternion; }}

二、BluetoothService

public class BluetoothService {
private static final UUID MY_UUID = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); private Context context; //蓝牙适配器 private BluetoothAdapter mAdapter; private Handler mHandler; //当前传感器设备的个数，即要开启的线程个数，用于设置线程数组的大小 //这里默认为1，因为我们目前只需要和一个传感器连接，比如：你要连接两个硬件设备，那就设置值为2，这样就会开启两个线程，分别去执行想要操作 public static final intSENSEOR_NUM=1; private AcceptThread mAcceptThread; // 请求连接的监听进程 private ConnectThread mConnectThread; // 连接一个设备的进程 public ConnectedThread[] mConnectedThread=new ConnectedThread[SENSEOR_NUM]; // 已经连接之后的管理进程private int mState; // 当前状态// 指明连接状态的常量 public static final int STATE_NONE = 0; //没有连接 public static final int STATE_LISTEN = 1; //等待连接 public static final int STATE_CONNECTING = 2; //正在连接 public static final int STATE_CONNECTED = 3; //已经连接public BluetoothService(Context context, Handler mHandler) { this.context = context; this.mHandler = mHandler; mAdapter = BluetoothAdapter.getDefaultAdapter(); //获取蓝牙适配器 mState = STATE_NONE ; //当前连接状态：未连接 }// 参数 index 是硬件设备的id ，随便设的，目的在于当同时连接多个硬件设备的时候，根据此id进行区分 public synchronized void connect(BluetoothDevice device, int index) {//连接一个蓝牙时，将该设备的蓝牙连接线程关闭，如果有的话 //demo就只有一个硬件设备，默认该设备id 取值index=1; if (mConnectedThread[index-1] != null) { mConnectedThread[index-1].cancel(); mConnectedThread[index-1]=null; } mConnectThread=new ConnectThread(device,index); mConnectThread.start(); setState(STATE_CONNECTING); }private class ConnectThread extends Thread{ private final BluetoothSocket mmSocket; private final BluetoothDevice mmDevice; private int index; public ConnectThread(BluetoothDevice device,int index) { mmDevice = device; this.index=index; BluetoothSocket tmp = null; try { tmp = device.createRfcommSocketToServiceRecord(MY_UUID); // Get a BluetoothSocket for a connection with the given BluetoothDevice } catch (IOException e) {} mmSocket = tmp; }public void run() {setName("ConnectThread"); //当连接成功，取消蓝牙适配器搜索蓝牙设备的操作，因为搜索操作非常耗时 mAdapter.cancelDiscovery(); // Always cancel discovery because it will slow down a connectiontry { mmSocket.connect(); // This is a blocking call and will only return on a successful connection or an exception } catch (IOException e) { connectionFailed(this.index); try { mmSocket.close(); } catch (IOException e2) {}BluetoothService.this.start(); // 引用来说明要调用的是外部类的方法 run return; }synchronized (BluetoothService.this) {// Reset the ConnectThread because we‘re done mConnectThread = null; } connected(mmSocket, mmDevice,index); // Start the connected thread }public void cancel() { try { mmSocket.close(); } catch (IOException e) { } } }class ConnectedThread extends Thread{ private BluetoothSocket mmSocket; private InputStream mmInStream; private OutputStream mmOutStream; private int index; private Queue< Byte> queueBuffer = new LinkedList< Byte> (); private byte[] packBuffer = new byte[11]; //构造方法 public ConnectedThread(BluetoothSocket socket,int index) { mmSocket = socket; InputStream tmpIn = null; OutputStream tmpOut = null; this.index=index; // Get the BluetoothSocket input and output streams try { tmpIn = socket.getInputStream(); tmpOut = socket.getOutputStream(); } catch (IOException e) {}mmInStream = tmpIn; mmOutStream = tmpOut; }// 数组大小看你的数据需求，这里存的是你处理蓝牙传输来的字节数据之后实际要用到的数据 private float [] fData=https://www.songbingjia.com/android/new float[31]; @Override public void run() { byte[] tempInputBuffer = new byte[1024]; int acceptedLen = 0; //记录每次读取数据的数据长度 byte sHead; long lLastTime = System.currentTimeMillis(); //获取开始时间 while(true){ try { acceptedLen = mmInStream.read(tempInputBuffer); //返回接收的长度 //从缓冲区中读取数据 for (int i = 0; i < acceptedLen; i++) { queueBuffer.add(tempInputBuffer[i]); } // 这里需要按个人硬件数据的情况自行修改了 // 如果你的硬件蓝牙传输一个包有11个字节，那queueBuffer.size()> =11 // 如果你的硬件蓝牙传输一个包有21个字节，那queueBuffer.size()> =21 while (queueBuffer.size()> =11){ //返回队首并删除，判断队首是不是0x55，如果不是，说明不是一个包的数据，跳过， //注意这里的0x55是你的包的首字节 if (queueBuffer.poll()!=0x55) continue; // 进入到这里，说明得到一个包的数据了，然后就要根据个人硬件的数据情况，将byte类型的数据转换为float类型的数据
sHead = queueBuffer.poll(); //返回队首并删除

// 现在得到的就是你数据部分了，如果有9位字节代表数据，j< 9 ，如果有19位字节代表数据，j< 19

//将字节数组存到packBuffer[]数据中，用于byte--> float数据的转换 for (int j = 0; j < 9; j++) { packBuffer[j] = queueBuffer.poll(); } switch (sHead) {// case 0x52://角速度 fData[3] = ((((short) packBuffer[1]) < < 8) | ((short) packBuffer[0] & 0xff)) / 32768.0f * 2000; fData[4] = ((((short) packBuffer[3]) < < 8) | ((short) packBuffer[2] & 0xff)) / 32768.0f * 2000; fData[5] = ((((short) packBuffer[5]) < < 8) | ((short) packBuffer[4] & 0xff)) / 32768.0f * 2000; fData[17] = ((((short) packBuffer[7]) < < 8) | ((short) packBuffer[6] & 0xff)) / 100.0f; break; case 0x53://角度 fData[6] = ((((short) packBuffer[1]) < < 8) | ((short) packBuffer[0] & 0xff)) / 32768.0f * 180; fData[7] = ((((short) packBuffer[3]) < < 8) | ((short) packBuffer[2] & 0xff)) / 32768.0f * 180; fData[8] = ((((short) packBuffer[5]) < < 8) | ((short) packBuffer[4] & 0xff)) / 32768.0f * 180; fData[17] = ((((short) packBuffer[7]) < < 8) | ((short) packBuffer[6] & 0xff)) / 100.0f; break; case 0x59://四元数 fData[23] = ((((short) packBuffer[1]) < < 8) | ((short) packBuffer[0] & 0xff)) / 32768.0f; fData[24] = ((((short) packBuffer[3]) < < 8) | ((short) packBuffer[2] & 0xff))/32768.0f; fData[25] = ((((short) packBuffer[5]) < < 8) | ((short) packBuffer[4] & 0xff))/32768.0f; fData[26] = ((((short) packBuffer[7]) < < 8) | ((short) packBuffer[6] & 0xff))/32768.0f; break; } } long lTimeNow = System.currentTimeMillis(); // 获取收据转换之后的时间 // 如果数据处理后的时间与接收到数据的时间的时间差> 80 则发送消息传输数据， // 这个时间需要看你硬件一秒钟发送的包的个数 if (lTimeNow - lLastTime > 80) { lLastTime = lTimeNow; Message msg = mHandler.obtainMessage(MainActivity.MESSAGE_READ); Bundle bundle = new Bundle(); bundle.putString("index",String.valueOf(this.index)); bundle.putFloatArray("Data", fData); msg.setData(bundle); mHandler.sendMessage(msg); } } catch (IOException e) { connectionLost(this.index); e.printStackTrace(); } } } public void cancel() { try { mmSocket.close(); } catch (IOException e) {} } } //连接失败 private void connectionFailed(int index) { setState(STATE_LISTEN); // Send a failure message back to the Activity Message msg = mHandler.obtainMessage(MainActivity.MESSAGE_TOAST); Bundle bundle = new Bundle(); bundle.putString("toast", "未能连接设备"+index); bundle.putInt("device_id",index); msg.setData(bundle); mHandler.sendMessage(msg); } // 连接丢失 private void connectionLost(int index) { setState(STATE_LISTEN); Message msg = mHandler.obtainMessage(MainActivity.MESSAGE_TOAST); Bundle bundle = new Bundle(); bundle.putString("toast", "设备丢失"+index); bundle.putInt("device_id",index); msg.setData(bundle); mHandler.sendMessage(msg); }//用于蓝牙连接的Activity onResume()方法 public synchronized void start() { // Cancel any thread attempting to make a connection if (mConnectThread != null) { mConnectThread.cancel(); mConnectThread = null; }if (mAcceptThread == null) { mAcceptThread = new AcceptThread(); mAcceptThread.start(); } setState(STATE_LISTEN); }public synchronized void connected(BluetoothSocket socket,BluetoothDevice device,int index) { Log.d("MAGIKARE","连接到线程"+index); // Cancel the thread that completed the connection if (mConnectThread != null) { mConnectThread.cancel(); mConnectThread = null; } // Cancel the accept thread because we only want to connect to one device if (mAcceptThread != null) { mAcceptThread.cancel(); mAcceptThread = null; }// Start the thread to manage the connection and perform transmissions mConnectedThread[index-1] = new ConnectedThread(socket,index); mConnectedThread[index-1].start(); // Send the name of the connected device back to the UI Activity Message msg = mHandler.obtainMessage(MainActivity.MESSAGE_DEVICE_NAME); Bundle bundle = new Bundle(); bundle.putString("device_name", device.getName()+" "+index); msg.setData(bundle); mHandler.sendMessage(msg); setState(STATE_CONNECTED); }private synchronized void setState(int state) { mState = state; // Give the new state to the Handler so the UI Activity can update mHandler.obtainMessage(MainActivity.MESSAGE_STATE_CHANGE, state, -1).sendToTarget(); }private class AcceptThread extends Thread { // The local server socket private final BluetoothServerSocket mmServerSocket; //private int index; public AcceptThread() { BluetoothServerSocket tmp = null; // this.index=index; // Create a new listening server socket try { tmp = mAdapter.listenUsingRfcommWithServiceRecord("BluetoothData", MY_UUID); } catch (IOException e) {} mmServerSocket = tmp; }public void run() { new Thread(new Runnable() { @Override public void run() {} }).start(); }public void cancel() {try { if(mmServerSocket!=null) { mmServerSocket.close(); } } catch (IOException e) {} } } public synchronized int getState() { return mState; }public synchronized void stop() { if (mConnectedThread != null) { for(int i=0; i< mConnectedThread.length; i++) { mConnectedThread[i].cancel(); } mConnectedThread = null; } if (mAcceptThread != null) { mAcceptThread.cancel(); mAcceptThread = null; } setState(STATE_NONE); } }

三、自定义即时变化的折线图：

public class MyView extends View { /*http://www.cnblogs.com/aibuli/p/950c34f2bc0d02cbd290dd6a8339d42a.html*/ //坐标轴原点的位置 private int xPoint=60; private int yPoint=260; //刻度长度 private int xScale=8; //8个单位构成一个刻度 private int yScale=40; //x与y坐标轴的长度 private int xLength=580; private int yLength=480; private int MaxDataSize=xLength/xScale; //横坐标最多可绘制的点private List< Float> data=https://www.songbingjia.com/android/new ArrayList< Float> (); //存放纵坐标所描绘的点private String[] yLabel=new String[yLength/yScale]; //Y轴的刻度上显示字的集合private Handler mh=new Handler(){ public void handleMessage(android.os.Message msg) { if(msg.what==0){//判断接受消息类型 MyView.this.invalidate(); //刷新View } }; }; public MyView(Context context, AttributeSet attrs) { super(context, attrs); for (int i = 0; i < yLabel.length; i++) { yLabel[i]=(i+1)+"M/s"; } new Thread(new Runnable() { @Override public void run() { while(true){//在线程中不断往集合中增加数据 try { Thread.sleep(300); } catch (InterruptedException e) { e.printStackTrace(); } if(data.size()> MaxDataSize){//判断集合的长度是否大于最大绘制长度 data.remove(0); //删除头数据 } // 这里得到蓝牙设备得到的数据 float[] floats = MainActivity.GetAngleSpeed(1); data.add(floats[0]); mh.sendEmptyMessage(0); //发送空消息通知刷新 } } }).start(); }@Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); Paint paint=new Paint(); paint.setStyle(Paint.Style.STROKE); paint.setAntiAlias(true); paint.setColor(Color.RED); //绘制Y轴 canvas.drawLine(xPoint, yPoint-yLength, xPoint, yPoint, paint); //绘制Y轴左右两边的箭头 canvas.drawLine(xPoint, yPoint-yLength, xPoint-3,yPoint-yLength+6, paint); canvas.drawLine(xPoint, yPoint-yLength, xPoint+3,yPoint-yLength+6, paint); //Y轴上的刻度与文字 for (int i = 0; i * yScale< yLength; i++) { canvas.drawLine(xPoint, yPoint-i*yScale, xPoint+5, yPoint-i*yScale, paint); //刻度 canvas.drawText(yLabel[i], xPoint-50, yPoint-i*yScale, paint); //文字 } //X轴 canvas.drawLine(xPoint, yPoint, xPoint+xLength, yPoint, paint); //如果集合中有数据 if(data.size()> 1){ for (int i = 1; i < data.size(); i++) {//依次取出数据进行绘制 canvas.drawLine(xPoint+(i-1)*xScale, yPoint-data.get(i-1)*yScale, xPoint+i*xScale, yPoint-data.get(i)*yScale, paint); } }} }

相关知识：浅谈Bluetooth蓝牙开发
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【Android项目实战（二十六）（蓝牙连接硬件设备开发规范流程）】