Android串口通信

使用Google的开源库android-serialport-api

一、搭建项目环境

在Main文件夹下创建 libs 与 jniLibs 文件夹，然后将库中对应的文件拷入
在 java 文件夹下创建 android_serialport_api （注意：因为用的谷歌原生so库，所以SerialPort类的包名一定要是android_serialport_api，如果想修改这个包名，就需要重新生成对应的so库）

然后在 build.gradle 中添加

sourceSets {
    main { 
        jni.srcDirs = []
    }
}

二、数据通信

创建串口工具类：

public class SerialPortUtil {

    private static volatile SerialPortUtil serialPortUtil;

    private SerialPortUtil() {

    }

    public static SerialPortUtil getInstance() {
        if (serialPortUtil == null) {
            synchronized (SerialPortUtil.class) {
                if (serialPortUtil == null) {
                    serialPortUtil = new SerialPortUtil();
                }
            }
        }
        return serialPortUtil;
    }

    private SerialPort serialPort;
    private OutputStream outputStream;
    private InputStream inputStream;

    /**
     * 打开串口
     */
    public void openSerialPort() {
        try {
            /*设置打开的串口*/
            final String portPath = "/dev/ttyS0";
            /*设置波特率*/
            final int baudRate = 115200;
            serialPort = new SerialPort(new File(portPath), baudRate, 0);
            outputStream = serialPort.getOutputStream();
            inputStream = serialPort.getInputStream();
            /*开启线程读取数据*/
            new ReadThread().start();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 读取数据的线程
     */
    private class ReadThread extends Thread {
        @Override
        public void run() {
            super.run();
            while (!isInterrupted()) {
                int size;
                try {
                    byte[] buffer = new byte[64];
                    if (inputStream == null)
                        return;
                    size = inputStream.read(buffer);
                    if (size > 0) {
                        if (dataReceiveListener != null) {
                            dataReceiveListener.receiveData(buffer, size);
                        }
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                    return;
                }
            }
        }
    }

    /**
     * 关闭串口
     */
    public void closeSerialPort() {
        try {
            inputStream.close();
            outputStream.close();
            serialPort.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 发送数据到串口
     *
     * @param data 需要发送的数据
     */
    public void sendDataToSerialPort(byte[] data) {
        try {
            int dataLength = data.length;
            if (dataLength > 0) {
                outputStream.write(data);
                outputStream.write('\n');
                outputStream.flush();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public interface DataReceiveListener {
        void receiveData(byte[] data, int size);
    }

    private DataReceiveListener dataReceiveListener;

    public void setOnDataReceiveListener(DataReceiveListener dataReceiveListener) {
        this.dataReceiveListener = dataReceiveListener;
    }
}

创建串口信息获取类：

public class SerialPortFinder {

    public class Driver {
        public Driver(String name, String root) {
            mDriverName = name;
            mDeviceRoot = root;
        }
        private String mDriverName;
        private String mDeviceRoot;
        Vector<File> mDevices = null;
        public Vector<File> getDevices() {
            if (mDevices == null) {
                mDevices = new Vector<File>();
                File dev = new File("/dev");
                File[] files = dev.listFiles();
                int i;
                for (i=0; i<files.length; i++) {
                    if (files[i].getAbsolutePath().startsWith(mDeviceRoot)) {
                        Log.d(TAG, "Found new device: " + files[i]);
                        mDevices.add(files[i]);
                    }
                }
            }
            return mDevices;
        }
        public String getName() {
            return mDriverName;
        }
    }

    private static final String TAG = "SerialPort";

    private Vector<Driver> mDrivers = null;

    Vector<Driver> getDrivers() throws IOException {
        if (mDrivers == null) {
            mDrivers = new Vector<Driver>();
            LineNumberReader r = new LineNumberReader(new FileReader("/proc/tty/drivers"));
            String l;
            while((l = r.readLine()) != null) {
                // Issue 3:
                // Since driver name may contain spaces, we do not extract driver name with split()
                String drivername = l.substring(0, 0x15).trim();
                String[] w = l.split(" +");
                if ((w.length >= 5) && (w[w.length-1].equals("serial"))) {
                    Log.d(TAG, "Found new driver " + drivername + " on " + w[w.length-4]);
                    mDrivers.add(new Driver(drivername, w[w.length-4]));
                }
            }
            r.close();
        }
        return mDrivers;
    }

    public String[] getAllDevices() {
        Vector<String> devices = new Vector<String>();
        // Parse each driver
        Iterator<Driver> itdriv;
        try {
            itdriv = getDrivers().iterator();
            while(itdriv.hasNext()) {
                Driver driver = itdriv.next();
                Iterator<File> itdev = driver.getDevices().iterator();
                while(itdev.hasNext()) {
                    String device = itdev.next().getName();
                    String value = String.format("%s (%s)", device, driver.getName());
                    devices.add(value);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return devices.toArray(new String[devices.size()]);
    }

    public String[] getAllDevicesPath() {
        Vector<String> devices = new Vector<String>();
        // Parse each driver
        Iterator<Driver> itdriv;
        try {
            itdriv = getDrivers().iterator();
            while(itdriv.hasNext()) {
                Driver driver = itdriv.next();
                Iterator<File> itdev = driver.getDevices().iterator();
                while(itdev.hasNext()) {
                    String device = itdev.next().getAbsolutePath();
                    devices.add(device);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return devices.toArray(new String[devices.size()]);
    }
}

使用方法

SerialPortUtil.getInstance().openSerialPort();
    SerialPortFinder finder = new SerialPortFinder();
    String[] allDevices = finder.getAllDevices();
    Log.e("LHG", Arrays.toString(allDevices));
    SerialPortUtil.getInstance().setOnDataReceiveListener(new SerialPortUtil.DataReceiveListener() {
        @Override
        public void receiveData(byte[] data, int size) {
            
        }
    });