Android - 串口通讯（SerialPort）

最早的博客Android 模拟串口通信过程_launch virtual serial port driver pro-CSDN博客里就是用过 Google 提供的 demo，最近想再写个其他的demo发现用起来有点麻烦，还需要导入其他 module，因此在网上找到了Android-SerialPort-API: https://github.com/licheedev/Android-SerialPort-API.git 也是Fork自Google开源的Android串口通信Demo。

话不多说，直接开搞。

目录

一、简单说明

1、添加依赖

2、创建串口通讯工具类 SerialPortUtil

3、示例 MainActivity

4、通过logcat验证app

二、注意

三、总结

四、demo地址

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一、简单说明

1、添加依赖

dependencies {...//添加依赖implementation ("com.licheedev:android-serialport:2.1.3")}

2、创建串口通讯工具类 SerialPortUtil

class SerialPortUtil {companion object {private const val TAG = "SerialPortUtil"val sInstances by lazy(LazyThreadSafetyMode.SYNCHRONIZED) {SerialPortUtil()}}private lateinit var mIOpenSerialPortListener: IOpenSerialPortListenerprivate lateinit var mISerialPortDataListener: ISerialPortDataListenerprivate lateinit var mSendingHandlerThread: HandlerThreadprivate lateinit var mSendingHandler: Handlerprivate lateinit var mSerialPortReceivedThread: SerialPortReceivedThreadprivate lateinit var mFileInputStream: FileInputStreamprivate lateinit var mFileOutputStream: FileOutputStreamprivate lateinit var serialPort: SerialPort/*** 打开串口方法*/fun open(path: File) {try {serialPort = SerialPort.newBuilder(path, 9600) // 校验位；0:无校验位(NONE，默认)；1:奇校验位(ODD);2:偶校验位(EVEN).build()mFileInputStream = serialPort.inputStream as FileInputStreammFileOutputStream = serialPort.outputStream as FileOutputStream} catch (e: SecurityException) {mIOpenSerialPortListener.onFail(path, Status.NO_READ_WRITE_PERMISSION)return} catch (e: Exception) {mIOpenSerialPortListener.onFail(path, Status.OPEN_FAIL)return}mIOpenSerialPortListener.onSuccess(path)startSendThread()startReceivedThread()}/*** 发送数据*/fun sendBytes(bytes: ByteArray?): Boolean {try {Runnable {val message = Message.obtain()message.obj = bytesmSendingHandler.sendMessage(message)Thread.sleep(100)}.run()} catch (e: Exception) {Log.e(TAG, "sendBytes: 发送数据失败 " + e.message)return false}return true}/*** 开启发送消息线程*/private fun startSendThread() {Log.d(TAG, "startSendThread: 开启发送消息线程")mSendingHandlerThread = HandlerThread("mSendingHandlerThread")mSendingHandlerThread.start()mSendingHandler = object : Handler(mSendingHandlerThread.looper) {override fun handleMessage(msg: Message) {val sendBytes: ByteArray? = msg.obj as ByteArray?if ((null != sendBytes) && (sendBytes.isNotEmpty())) {try {mFileOutputStream.write(sendBytes)mISerialPortDataListener.onDataSend(sendBytes)} catch (e: java.io.IOException) {e.printStackTrace()}}}}}/*** 停止发送消息线程*/fun stopSendThread() {Log.d(TAG, "stopSendThread: 停止发送消息线程")mSendingHandlerThread.interrupt()mSendingHandlerThread.quit()}/*** 开启接收消息的线程*/private fun startReceivedThread() {Log.d(TAG, "startReceivedThread: 开启接受消息线程")mSerialPortReceivedThread = object : SerialPortReceivedThread(mFileInputStream) {override fun onDataReceived(bytes: ByteArray?) {mISerialPortDataListener.onDataReceived(bytes)}}mSerialPortReceivedThread.start()}/*** 停止接收消息的线程*/fun stopReceivedThread() {Log.d(TAG, "stopReceivedThread: 停止接收消息的线程")mSerialPortReceivedThread.release()serialPort.tryClose()}/*** 设置串口打开的监听*/fun setIOpenSerialPortListener(iOpenSerialPortListener: IOpenSerialPortListener) {mIOpenSerialPortListener = iOpenSerialPortListener}/*** 设置串口数据收发的监听*/fun setISerialPortDataListener(iSerialPortDataListener: ISerialPortDataListener) {mISerialPortDataListener = iSerialPortDataListener}}

 在这里简单介绍些，在开启串口通讯后开启两个线程，分别处理send及received步骤。

3、示例 MainActivity

class MainActivity : Activity(), IOpenSerialPortListener, ISerialPortDataListener {companion object {private const val TAG = "MainActivity"private val FIND_CARD =byteArrayOf(0x20, 0x00, 0x80.toByte(), 0x04, 0x03, 0x03, 0x01, 0x00, 0x7a, 0x03)}override fun onCreate(savedInstanceState: Bundle?) {super.onCreate(savedInstanceState)setContentView(R.layout.activity_main)CrashHandler.sInstance.init(this)//0、设置su位置SerialPort.setSuPath("/system/xbin/su")//1、首先设置open监听SerialPortUtil.sInstances.setIOpenSerialPortListener(this)//2、设置串口监听SerialPortUtil.sInstances.setISerialPortDataListener(this)//3、open串口SerialPortUtil.sInstances.open(File("/dev/ttyS3"))//4、模拟发送命令SerialPortUtil.sInstances.sendBytes(FIND_CARD)}override fun onDestroy() {super.onDestroy()SerialPortUtil.sInstances.stopSendThread()SerialPortUtil.sInstances.stopReceivedThread()}override fun onSuccess(device: File?) {Log.d(TAG, "onSuccess: open成功")}override fun onFail(device: File?, status: Status?) {Log.d(TAG, "onFail: open失败，原因： $status")}override fun onDataReceived(bytes: ByteArray?) {Log.d(TAG, "onDataReceived: 接受数据: " + Arrays.toString(bytes))}override fun onDataSend(bytes: ByteArray?) {Log.d(TAG, "onDataSend: 发送数据: " + Arrays.toString(bytes))}}

4、通过logcat验证app

09:52:48.349 serial_port               D  Opening serial port /dev/ttyS3 with flags 0x2
09:52:48.349 serial_port               D  open() fd = 45
09:52:48.349 serial_port               D  Configuring serial port
09:52:48.359 MainActivity              D  onSuccess: open成功
09:52:48.359 SerialPortUtil            D  startSendThread: 开启发送消息线程
09:52:48.359 SerialPortUtil            D  startReceivedThread: 开启接受消息线程
09:52:48.359 SerialPortReceivedThread  I  run: available =  0
09:52:48.359 MainActivity              D  onDataSend: 发送数据: [32, 0, -128, 4, 3, 3, 1, 0, 122, 3]
09:52:48.529 BufferQueue               E  [com.lichang.source/com.lichang.source.MainActivity] connect: already connected (cur=1, req=1)
09:52:48.529 mali_winsys               D  EGLint new_window_surface(egl_winsys_display*, void*, EGLSurface, EGLConfig, egl_winsys_surface**, egl_color_buffer_format*, EGLBoolean) returns 0x3000
09:52:48.529 OpenGLRenderer            D  Enabling debug mode 0
09:52:51.609 SerialPortReceivedThread  I  run: size = 14
09:52:51.609 SerialPortReceivedThread  I  run: bytes = [32, 0, 0, 8, 4, 0, 8, 4, 28, 37, -117, -5, -74, 3]
09:52:51.609 MainActivity              D  onDataReceived: 接受数据: [32, 0, 0, 8, 4, 0, 8, 4, 28, 37, -117, -5, -74, 3]
09:52:51.609 SerialPortReceivedThread  I  run: available =  0
09:52:53.729 SerialPortReceivedThread  I  run: size = 22
09:52:53.729 SerialPortReceivedThread  I  run: bytes = [32, 0, 0, 16, 32, 17, 35, 69, 103, -113, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 80, 3]
09:52:53.729 MainActivity              D  onDataReceived: 接受数据: [32, 0, 0, 16, 32, 17, 35, 69, 103, -113, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 80, 3]
09:52:53.729 SerialPortReceivedThread  I  run: available =  0
09:53:03.239 dalvikvm                  D  Debugger has detached; object registry had 1 entries
09:53:03.249 dalvikvm                  D  GC_CONCURRENT freed 222K, 15% free 2334K/2744K, paused 1ms+1ms, total 12ms
09:53:12.419 SerialPortUtil            D  stopSendThread: 停止发送消息线程
09:53:12.419 SerialPortUtil            D  stopReceivedThread: 停止接收消息的线程
09:53:12.419 serial_port               D  close(fd = 45)

二、注意

为了在Android上读/写串行端口，你需要在设备上安装su binary(这可以通过root设备来完成)。通常，具有串口通信能力的Android设备已将su安装在默认路径下。

默认的 su 路径使用的是 “/system/bin/su”

三、总结

在新项目中快速应用，可以先导入依赖，然后copy示例中的 com/lichang/source/serialport文件夹，即可按照 3、示例 MainActivity 钓箱串口工具类。

四、demo地址

serialport-demo_kt: 使用 implementation ("com.licheedev:android-serialport:2.1.3")