android 中,USB 设备的路径映射到一个虚拟的串口设备上
时间: 2024-02-11 07:05:22 浏览: 26
在 Android 中,您可以使用 Android 操作系统提供的 USB Host API 将 USB 设备映射到虚拟的串口设备上。具体步骤如下:
1. 首先,在 AndroidManifest.xml 文件中添加以下权限:
```
<uses-feature android:name="android.hardware.usb.host" />
<uses-permission android:name="android.permission.USB_PERMISSION" />
```
2. 在您的 Activity 或 Service 中获取 USB 设备的权限,并打开 USB 设备:
```
private static final String ACTION_USB_PERMISSION = "com.android.example.USB_PERMISSION";
private UsbManager mUsbManager;
private UsbDevice mUsbDevice;
private PendingIntent mPermissionIntent;
private UsbInterface mUsbInterface;
private UsbEndpoint mUsbEndpoint;
private void setupUsb() {
mUsbManager = (UsbManager) getSystemService(Context.USB_SERVICE);
mPermissionIntent = PendingIntent.getBroadcast(this, 0, new Intent(ACTION_USB_PERMISSION), 0);
IntentFilter filter = new IntentFilter(ACTION_USB_PERMISSION);
registerReceiver(mUsbReceiver, filter);
HashMap<String, UsbDevice> deviceList = mUsbManager.getDeviceList();
for (UsbDevice device : deviceList.values()) {
if (device.getVendorId() == YOUR_VENDOR_ID && device.getProductId() == YOUR_PRODUCT_ID) {
mUsbDevice = device;
break;
}
}
if (mUsbDevice != null) {
mUsbManager.requestPermission(mUsbDevice, mPermissionIntent);
}
}
private final BroadcastReceiver mUsbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (ACTION_USB_PERMISSION.equals(action)) {
synchronized (this) {
UsbDevice device = intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
if (device != null) {
mUsbInterface = device.getInterface(0);
mUsbEndpoint = mUsbInterface.getEndpoint(0);
UsbDeviceConnection connection = mUsbManager.openDevice(device);
connection.claimInterface(mUsbInterface, true);
}
} else {
Log.d(TAG, "permission denied for device " + device);
}
}
}
}
};
```
其中,`YOUR_VENDOR_ID` 和 `YOUR_PRODUCT_ID` 分别是 USB 设备的 Vendor ID 和 Product ID。
3. 接下来,您可以使用 Android 操作系统提供的串口通信 API 将 USB 设备映射到虚拟的串口设备上。例如,您可以使用 `SerialPort` 类来创建虚拟串口设备:
```
private SerialPort mSerialPort;
private OutputStream mOutputStream;
private InputStream mInputStream;
private void setupSerialPort() {
try {
mSerialPort = new SerialPort(mUsbDevice, mUsbEndpoint);
mOutputStream = mSerialPort.getOutputStream();
mInputStream = mSerialPort.getInputStream();
} catch (IOException e) {
e.printStackTrace();
}
}
```
现在,您就可以使用 `mInputStream` 和 `mOutputStream` 对象来访问 USB 设备了。