Custom Android Embed Board with External USB Camera Support

This project demonstrates the integration of an external USB camera with an Android embed board. The system utilizes UsbManager and UsbDevice for managing USB device connections, and the libusbcamera library for handling the camera functionality.

System Requirements

...

Ensure the following permissions and features are declared in your AndroidManifest.xml:

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.INTERNET"/>
<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.USB_PERMISSION" />
<uses-permission android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
<uses-permission android:name="android.hardware.usb.action.USB_DEVICE_DETACHED" />

Layout

Use a TextureView to preview the camera feed in your layout:

<TextureView
    android:id="@+id/yourId"
    android:layout_width="match_parent"
    android:layout_height="match_parent"/>

USB Monitor for Permission

Include the USBMonitor class to manage USB permissions.

private final USBMonitor.OnDeviceConnectListener onDeviceConnectListener = new USBMonitor.OnDeviceConnectListener() {
    @Override
    public void onAttach(UsbDevice device) {
        // Open and initialize UVCCamera when USB device attached
        if (isUsbCamera(device)) {
            usbMonitor.requestPermission(device);
        }
    }
};

UVCCamera for Device Connection

Handle the connection and preview of the USB camera using the UVCCamera class.

public void onConnect(UsbDevice device, USBMonitor.UsbControlBlock ctrlBlock, boolean createNew) {
    if (isUsbCamera(device)) {
        if (camera1 == null) {
            Log.d(TAG, "Connecting to camera1: " + device.getDeviceName());
            camera1 = new UVCCamera();
            camera1.open(ctrlBlock);
            startPreview(camera1, textureView1);
        } else if (camera2 == null) {
            Log.d(TAG, "Connecting to camera2: " + device.getDeviceName());
            camera2 = new UVCCamera();
            camera2.open(ctrlBlock);
            startPreview2(camera2, textureView2);
        }
    }
}

Usage

USBMonitor Initialization Initialize the USBMonitor and set the OnDeviceConnectListener to handle device connections.

USBMonitor usbMonitor = new USBMonitor(this, onDeviceConnectListener);
usbMonitor.register();
Starting the Preview
Define methods to start the camera preview using the TextureView.


private void startPreview(UVCCamera camera, TextureView textureView) {
    // Set up the camera preview display
    SurfaceTexture surfaceTexture = textureView.getSurfaceTexture();
    if (surfaceTexture != null) {
        Surface surface = new Surface(surfaceTexture);
        camera.setPreviewDisplay(surface);
        camera.startPreview();
    }
}

Acknowledgments

This project is based on the work of saki4510t.