如何实现android studio串口通信

要在 Android Studio 中实现串口通信，可以按照以下步骤进行：

1. 在 AndroidManifest.xml 文件中添加以下权限：

   <uses-permission android:name="android.permission.INTERNET"/>
   <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
   <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
   <uses-permission android:name="android.permission.WAKE_LOCK"/>
   <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
   <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
   <uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
   <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
   <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
   <uses-permission android:name="android.permission.BLUETOOTH"/>
   <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
   <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
   <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
   <uses-permission android:name="android.permission.READ_PHONE_STATE"/>
   <uses-feature android:name="android.hardware.usb.host" />

2. 在 build.gradle 文件中添加以下依赖项：

   implementation 'com.felhr:usbserial:2.0.2'
   implementation 'com.github.mik3y:usb-serial-for-android:v2.0.0'

3. 创建一个 SerialPort 类来处理串口通信，如下所示：

   public class SerialPort {
       private UsbSerialPort port;
       private UsbSerialDriver driver;
       private UsbDevice device;
       private Context context;
       private UsbManager manager;
   
       public SerialPort(UsbDevice device, Context context) {
           this.device = device;
           this.context = context;
           this.manager = (UsbManager) context.getSystemService(Context.USB_SERVICE);
           driver = UsbSerialProber.getDefaultProber().probeDevice(device);
           port = driver.getPorts().get(0);
       }
   
       public void open() throws IOException {
           if (port != null) {
               port.open(manager.openDevice(driver.getDevice()));
               port.setParameters(9600, 8, UsbSerialPort.STOPBITS_1, UsbSerialPort.PARITY_NONE);
           }
       }
   
       public void close() throws IOException {
           if (port != null) {
               port.close();
           }
       }
   
       public void write(byte[] data) throws IOException {
           if (port != null) {
               port.write(data, 1000);
           }
       }
   
       public byte[] read() throws IOException {
           if (port != null) {
               byte[] buffer = new byte[1000];
               int numBytesRead = port.read(buffer, 1000);
               byte[] data = new byte[numBytesRead];
               System.arraycopy(buffer, 0, data, 0, numBytesRead);
               return data;
           }
           return null;
       }
   }

4. 在 Activity 中使用 SerialPort 类进行串口通信，如下所示：

   public class MainActivity extends AppCompatActivity {
       private SerialPort serialPort;
   
       @Override
       protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_main);
           UsbManager manager = (UsbManager) getSystemService(Context.USB_SERVICE);
           HashMap<String, UsbDevice> deviceList = manager.getDeviceList();
           for (UsbDevice device : deviceList.values()) {
               if (device.getVendorId() == VENDOR_ID && device.getProductId() == PRODUCT_ID) {
                   serialPort = new SerialPort(device, this);
                   break;
               }
           }
       }
   
       @Override
       protected void onResume() {
           super.onResume();
           try {
               serialPort.open();
           } catch (IOException e) {
               e.printStackTrace();
           }
       }
   
       @Override
       protected void onPause() {
           super.onPause();
           try {
               serialPort.close();
           } catch (IOException e) {
               e.printStackTrace();
           }
       }
   
       public void send() {
           try {
               byte[] data = "Hello World".getBytes();
               serialPort.write(data);
           } catch (IOException e) {
               e.printStackTrace();
           }
       }
   
       public void receive() {
           try {
               byte[] data = serialPort.read();
               String message = new String(data, StandardCharsets.UTF_8);
           } catch (IOException e) {
               e.printStackTrace();
           }
       }
   }

上述代码中的 VENDOR_ID 和 PRODUCT_ID 应该替换成实际的 USB 设备的供应商 ID 和产品 ID。