项目中有一个新的需求，要求可以连接一个USB体温枪，APP可以从体温枪中读取到体温数据，一番搜寻之后发现一个封装很棒的USB通信库。

github地址：

准备工作

1. 从 github 上 clone 这个库的源文件

2. 在Android Studio中引入模块

   

3. 在build.gradle中添加依赖compile project(path: ':usbSerialForAndroid')

4. 复制 到项目的 res/xml/ 文件夹下

   

5. 配置 AndroidManifest.xml 文件

使用

示例代码解析：

// 获取系统服务得到UsbManager实例UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);//查找所有插入的设备List
     
       availableDrivers = UsbSerialProber.getDefaultProber().findAllDrivers(manager);if (availableDrivers.isEmpty()) {  return;}// 打开设备，建立通信连接 UsbSerialDriver driver = availableDrivers.get(0); UsbDeviceConnection connection = manager.openDevice(driver.getDevice()); if (connection == null) { // You probably need to call UsbManager.requestPermission(driver.getDevice(), ..) return; } //打开端口，设置端口参数，读取数据 UsbSerialPort port = driver.getPorts().get(0); try { port.open(connection); //四个参数分别是：波特率，数据位，停止位，校验位 port.setParameters(115200, 8, UsbSerialPort.STOPBITS_1, UsbSerialPort.PARITY_NONE); byte buffer[] = new byte[16]; int numBytesRead = port.read(buffer, 1000); Log.d(TAG, "Read " + numBytesRead + " bytes."); } catch (IOException e) { // Deal with error. } finally { port.close(); }
     

上述代码是库作者写的一段示例代码，可以看出使用上非常简单，下面的代码演示了如何将USB操作都封装到一个类里。

public class TemperatureUsbControl {    private static final String TAG = TemperatureUsbControl.class.getSimpleName(); private static final String TEMPERATURE_USB_VENDOR_ID = "067B"; //供应商id private static final String TEMPERATURE_USB_PRODUCT_ID = "2303"; //产品id private Context mContext; private UsbManager mUsbManager; //USB管理器 private UsbSerialPort sTemperatureUsbPort = null; //接体温枪的usb端口 private SerialInputOutputManager mSerialIoManager; //输入输出管理器（本质是一个Runnable） private final ExecutorService mExecutor = Executors.newSingleThreadExecutor(); //用于不断从端口读取数据 //数据输入输出监听器 private final SerialInputOutputManager.Listener mListener = new SerialInputOutputManager.Listener() { @Override public void onRunError(Exception e) { Log.d(TAG, "Runner stopped."); } @Override public void onNewData(final byte[] data) { Log.d(TAG, "new data."); } }; public TemperatureUsbControl(Context context) { mContext = context; } public void initUsbControl() { mUsbManager = (UsbManager) mContext.getSystemService(Context.USB_SERVICE); //全部设备 List
     
       usbSerialDrivers = UsbSerialProber.getDefaultProber().findAllDrivers(mUsbManager); //全部端口 List
      
        usbSerialPorts = new ArrayList
       
        (); for (UsbSerialDriver driver : usbSerialDrivers) { List
        
          ports = driver.getPorts(); Log.d(TAG, String.format("+ %s: %s port%s", driver, Integer.valueOf(ports.size()), ports.size() == 1 ? "" : "s")); usbSerialPorts.addAll(ports); } String vendorId; String productId; //校验设备，设备是 2303设备 for (UsbSerialPort port : usbSerialPorts) { UsbSerialDriver driver = port.getDriver(); UsbDevice device = driver.getDevice(); vendorId = HexDump.toHexString((short) device.getVendorId()); productId = HexDump.toHexString((short) device.getProductId()); if (vendorId.equals(TEMPERATURE_USB_VENDOR_ID) && productId.equals(TEMPERATURE_USB_PRODUCT_ID)) { sTemperatureUsbPort = port; } } if (sTemperatureUsbPort != null) { //成功获取端口，打开连接 UsbDeviceConnection connection = mUsbManager.openDevice(sTemperatureUsbPort.getDriver().getDevice()); if (connection == null) { Log.e(TAG, "Opening device failed"); return; } try { sTemperatureUsbPort.open(connection); //设置波特率 sTemperatureUsbPort.setParameters(4800, 8, UsbSerialPort.STOPBITS_1, UsbSerialPort.PARITY_NONE); } catch (IOException e) { //打开端口失败，关闭！ Log.e(TAG, "Error setting up device: " + e.getMessage(), e); try { sTemperatureUsbPort.close(); } catch (IOException e2) { // Ignore. } sTemperatureUsbPort = null; return; } } else { //提示未检测到设备 } } public void onDeviceStateChange() { //重新开启USB管理器 stopIoManager(); startIoManager(); } private void startIoManager() { if (sTemperatureUsbPort != null) { Log.i(TAG, "Starting io manager .."); mSerialIoManager = new SerialInputOutputManager(sTemperatureUsbPort, mListener); mExecutor.submit(mSerialIoManager); //实质是用一个线程不断读取USB端口 } } private void stopIoManager() { if (mSerialIoManager != null) { Log.i(TAG, "Stopping io manager .."); mSerialIoManager.stop(); mSerialIoManager = null; } } public void onPause() { stopIoManager(); if (sTemperatureUsbPort != null) { try { sTemperatureUsbPort.close(); } catch (IOException e) { // Ignore. } sTemperatureUsbPort = null; } } }
        
       
      
     

在Activity中使用：

@Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState); setContentView(R.layout.activity_punch); initUsbControl(); //初始化USB控制器 } /** * 初始化USB */ private void initUsbControl() { mTemperatureUsbControl = new TemperatureUsbControl(mContext); mTemperatureUsbControl.initUsbControl(); } @Override protected void onResume() { super.onResume(); IntentFilter usbFilter = new IntentFilter(); usbFilter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED); usbFilter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED); registerReceiver(mUsbReceiver, usbFilter); mTemperatureUsbControl.onDeviceStateChange(); } @Override protected void onPause() { super.onPause(); mTemperatureUsbControl.onPause(); unregisterReceiver(mUsbReceiver); } /** * 用于检测usb插入状态的BroadcasReceiver */ private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() { public void onReceive(Context context, Intent intent) { String action = intent.getAction(); if (UsbManager.ACTION_USB_DEVICE_ATTACHED.equals(action)) { //设备插入 mTemperatureUsbControl.initUsbControl(); mTemperatureUsbControl.onDeviceStateChange(); Log.e(TAG, "ACTION_USB_DEVICE_ATTACHED"); } else if (UsbManager.ACTION_USB_DEVICE_DETACHED.equals(action)) { //设备移除 mTemperatureUsbControl.onPause(); Log.e(TAG, "ACTION_USB_DEVICE_DETACHED"); } } };

读到的数据如果需要在Activity中使用，可以使用EventBus来完成~