Calculating pixel_clk_hz for Jetson Orin Nano with Custom Camera

Issue Overview

Users of the Jetson Orin Nano development board are experiencing difficulties in configuring the correct pixel_clk_hz value in the device tree for a custom camera setup. The specific camera has the following specifications:

• Resolution: 2880 x 1880
• Format: RAW12
• Frame rate: 46 fps
• Sensor data rate per lane: 2.5G
• Current configuration: 4-lane mode on a custom carrier board

The user has set pixel_clk_hz = "400000000" but is encountering instability issues, sometimes failing to receive data. Additional commands are required for reception, suggesting potential configuration problems.

Possible Causes

1. Incorrect pixel_clk_hz calculation: The user may have miscalculated the required pixel clock frequency, leading to synchronization issues between the camera and the Jetson board.

2. Mismatched data rates: The set pixel clock might not match the camera’s output data rate, causing instability in data reception.

3. Device tree configuration errors: Other parameters in the device tree might be incorrectly set, affecting the camera interface’s functionality.

4. Hardware limitations: The custom carrier board or the Jetson Orin Nano might have limitations in handling the high data rate from the camera.

5. Driver issues: The camera driver might not be fully compatible with the custom setup, requiring additional configuration or updates.

6. Power supply instability: Inadequate or unstable power supply could cause intermittent failures in high-speed data reception.

Troubleshooting Steps, Solutions & Fixes

1. Recalculate pixel_clk_hz:
   Based on the provided information and calculations, the correct pixel_clk_hz value should be approximately 833 MHz. Update the device tree with:

   pixel_clk_hz = "833000000";
   

2. Verify camera link configuration:
   Ensure that the MIPI CSI-2 interface is correctly configured for 4-lane mode in the device tree and camera driver settings.

3. Check power supply:
   Verify that the power supply to the Jetson Orin Nano and the camera is stable and sufficient. Use a multimeter to measure voltage levels under load.

4. Update Jetson software:
   Ensure you’re running the latest JetPack version and have all the necessary camera drivers installed.

5. Adjust BPMP clock settings:
   The following commands should be executed to unlock clock rates:

   echo 0 > /sys/kernel/debug/bpmp/debug/clk/vi/mrq_rate_locked
   echo 0 > /sys/kernel/debug/bpmp/debug/clk/isp/mrq_rate_locked
   echo 0 > /sys/kernel/debug/bpmp/debug/clk/nvcsi/mrq_rate_locked
   

   Then, set the clock rates appropriately based on your camera’s requirements.

6. Check camera datasheet:
   Verify all timing parameters from the camera’s datasheet and ensure they are correctly reflected in your device tree configuration.

7. Monitor system logs:
   Use dmesg and /var/log/syslog to check for any error messages related to the camera interface or clock configuration.

8. Test with lower resolution or frame rate:
   Temporarily reduce the camera’s resolution or frame rate to see if the issue persists. This can help isolate whether the problem is related to data rate limitations.

9. Verify lane configuration:
   Double-check that the physical connections for all four lanes are correct and that the camera is indeed operating in 4-lane mode.

10. Consult NVIDIA Developer Forums:
    If the issue persists, consider posting detailed logs and configuration files on the NVIDIA Developer Forums for more specific assistance.

Remember to reboot the Jetson Orin Nano after making changes to the device tree or clock configurations. If stability issues continue after implementing these fixes, consider reaching out to NVIDIA support or consulting with the camera manufacturer for more specific guidance.