Camera Selection Issue on Nvidia Jetson Orin Nano Dev Board with Multiple Cameras

Issue Overview

Users of the Nvidia Jetson Orin Nano Developer Kit have reported issues when attempting to use multiple cameras connected to the board, specifically a CSI camera (IMX219) and a USB camera. The main symptoms include:

• Failure to Open CSI Camera: When both cameras are connected, attempts to access the CSI camera using the gstreamer/nvarguscamerasrc element often result in errors indicating that the CSI camera cannot be opened.
• Error Logs: The logs show that the nvargus-daemon is trying to access the USB camera instead of the intended CSI camera, which leads to conflicts in device registration.
• Context of Issue: This problem typically occurs during system startup when both cameras are connected. The USB camera may take longer to initialize, potentially registering before the CSI camera, which causes it to occupy the /dev/video0 device node.

The issue has been consistently reported by users, significantly impacting their ability to utilize both cameras effectively in their applications.

Possible Causes

Several potential causes for this issue have been identified:

• Device Node Conflicts: The USB camera may register as /dev/video0, preventing nvarguscamerasrc from accessing the CSI camera if it also registers at that node.

• Driver and Software Limitations: The gstreamer/nvarguscamerasrc element does not support USB cameras, which can lead to failures when both types of cameras are connected.

• Initialization Order: If the USB camera initializes before the CSI camera, it can take over the default video node, causing conflicts.

• Configuration Errors: Incorrect sensor ID settings or failure to specify which camera to use can lead to unintended behavior.

• Environmental Factors: Power supply issues or overheating might affect device initialization times.

Troubleshooting Steps, Solutions & Fixes

To address the issue effectively, users can follow these troubleshooting steps and solutions:

1. Check Camera Initialization Order:

   • Ensure that the USB camera is connected after powering up the system or add a delay in its driver initialization to allow the CSI camera to register first.

2. Use Specific Video Node IDs:

   • Modify the UVC driver code to assign a specific video node number for the USB camera. For example:

     ret = video_register_device(vdev, VFL_TYPE_VIDEO, 99); 
     

   • This change will ensure that the USB camera registers at a specific node rather than automatically selecting an available one.

3. Verify Camera Capabilities:

   • Use v4l2-ctl commands to list and confirm capabilities of each connected camera:

     v4l2-ctl -d /dev/video0 --list-formats-ext
     v4l2-ctl -d /dev/video1 --list-formats-ext
     

4. Set Sensor ID for CSI Camera:

   • When using gstreamer/nvarguscamerasrc, explicitly set the sensor ID property:

     gst-launch-1.0 nvarguscamerasrc sensor-id=0 ! ...
     

   • This ensures that it targets the correct device regardless of its node assignment.

5. Use Alternative GStreamer Pipeline for USB Camera:

   • If utilizing both cameras simultaneously, use a different GStreamer pipeline for the USB camera:

     gst-launch-1.0 v4l2src device=/dev/video1 num-buffers=150 ! 'video/x-raw, width=1920, height=1080, framerate=30/1, format=YUY2' ! xvimagesink -e
     

6. Monitor and Adjust System Logs:

   • Regularly check logs from nvargus-daemon for any errors related to device initialization or conflicts.
   • Look for messages indicating which devices are being registered and in what order.

7. Best Practices for Future Use:

   • Always connect cameras in a known order or configure system settings to prioritize one type over another.
   • Consider using only one type of camera at a time if conflicts persist.

By following these steps and recommendations, users should be able to mitigate issues related to multiple cameras on their Nvidia Jetson Orin Nano Developer Kit and ensure smoother operation within their applications.