MIPI Data Acquisition Issue on Jetson Nano

Issue Overview

The user is experiencing difficulties with MIPI data acquisition on the Jetson Nano development board. The main concerns are:

• Inability to determine the width and height of incoming sensor data
• Frame discarding due to EBD (Embedded Data) related issues
• Challenges in receiving data when there’s a mismatch (even by one line) between the actual data and the driver settings
• Uncertainty about handling empty lines in FEBD, REBD, and OB data

The problem occurs during data reception from sensors, impacting the ability to process incoming frames correctly. The issue seems to be consistent, affecting the overall functionality of the image processing pipeline.

Possible Causes

1. Driver Configuration Mismatch: The driver settings may not align with the actual sensor output, causing frame discarding.

2. EBD Parsing Issues: The Jetson Nano might be struggling to parse Embedded Data correctly, leading to frame rejection.

3. Sensor Register Configuration: Improper configuration of sensor registers, particularly for data type settings, may cause parsing errors.

4. Buffer Size Limitations: Insufficient buffer size might prevent the system from accommodating slight variations in frame size.

5. Firmware or Software Bugs: There could be underlying issues in the Jetson Nano’s firmware or software stack handling MIPI data.

Troubleshooting Steps, Solutions & Fixes

1. Enable VI Tracing Logs:
   To gather more information about frame packet status and error flags, enable VI tracing logs:

   echo 1 > /sys/kernel/debug/tracing/tracing_on
   echo 30720 > /sys/kernel/debug/tracing/buffer_size_kb
   echo 1 > /sys/kernel/debug/tracing/events/tegra_rtcpu/enable
   echo 1 > /sys/kernel/debug/tracing/events/freertos/enable
   echo 2 > /sys/kernel/debug/camrtc/log-level
   echo > /sys/kernel/debug/tracing/trace
   cat /sys/kernel/debug/tracing/trace
   

   Analyze the output for detailed information about frame processing and error flags.

2. Adjust Driver Settings:

   • Review and adjust the driver settings to match the actual sensor output.
   • Experiment with slightly different width and height values to accommodate potential variations.

3. Sensor Register Configuration:

   • Ensure proper configuration of sensor registers, especially for data type settings.
   • If empty lines in FEBD, REBD, and OB data are causing issues, consider configuring the sensor to fill these with valid data types.

4. Buffer Size Optimization:

   • Increase buffer sizes to accommodate slight variations in frame size.
   • This can be done by modifying relevant kernel parameters or driver settings.

5. Firmware and Software Updates:

   • Check for and apply any available updates for the Jetson Nano’s firmware and software stack.
   • Look for specific patches addressing MIPI data handling issues.

6. Custom Frame Parsing:

   • If the built-in parsing is too strict, consider implementing a custom frame parsing logic that can handle slight variations in frame size.

7. Consult Nvidia Developer Forums:

   • Post detailed logs and sensor specifications on the Nvidia Developer Forums for more specialized assistance.
   • Include information about the specific sensor model and any custom modifications to the standard setup.

8. Hardware Verification:

   • Verify the physical connections between the sensor and the Jetson Nano.
   • Ensure that the MIPI lanes are properly connected and there’s no signal integrity issues.

9. Alternative Data Acquisition Methods:

   • If possible, explore alternative methods of acquiring sensor data that might be more flexible with frame size variations.

10. Debugging with External Tools:

    • Use external MIPI analyzers or oscilloscopes to capture and analyze the raw data stream from the sensor.
    • This can help identify any discrepancies between the sensor output and what the Jetson Nano is expecting.

Note: The issue remains partially unresolved as per the forum discussion. Further investigation may be needed, especially regarding the handling of empty lines in FEBD, REBD, and OB data. Users experiencing similar issues are encouraged to provide detailed logs and sensor specifications for more targeted assistance.