How to Enable MCP2515 on Orin Nano in L4T 36.3

Issue Overview

Users are experiencing difficulties enabling the MCP2515 module on the Jetson Orin Nano Developer Kit while using JetPack 6.0 (L4T 36.3). The main symptoms include confusion regarding device tree modifications and the absence of necessary overlay files in the compilation process. The issue arises during the setup phase when users attempt to configure SPI-CAN for the MCP2515 on a custom board. Users have referenced specific files, such as mcp251xfd.yaml and jetson-can-mcp251x.dtsi, but have found that the latter is not included in any device tree source (.dts) file, leading to complications in enabling the module. The frequency of this issue appears to be consistent among users attempting similar configurations, significantly impacting their ability to utilize CAN communication features effectively.

Possible Causes

1. Hardware Incompatibilities: The MCP2515 may not be fully compatible with the Orin Nano’s hardware configuration or power supply requirements.
2. Software Bugs or Conflicts: There may be unresolved bugs in JetPack 6.0 that affect device tree overlays or SPI configurations.
3. Configuration Errors: Incorrect modifications to the device tree could prevent proper initialization of the MCP2515.
4. Driver Issues: Missing or outdated drivers for the MCP2515 could lead to failure in recognizing or initializing the module.
5. Environmental Factors: Power supply inconsistencies or temperature issues could affect hardware performance.
6. User Errors: Misconfigurations during device tree edits or incorrect file paths may lead to errors.

Troubleshooting Steps, Solutions & Fixes

1. Verify Device Tree Modifications:

   • Ensure you are editing the correct device tree source file for your specific hardware configuration.
   • Reference the correct YAML bindings for MCP2515 by checking Linux_for_Tegra/source/kernel/kernel-jammy-src/Documentation/devicetree/bindings/net/can/microchip,mcp251xfd.yaml.

2. Check Overlay Files:

   • Investigate if jetson-can-mcp251x.dtsi is included in any .dts files. If not, consider creating a custom overlay that includes this file.
   • Ensure that all necessary overlays are compiled into .dtbo format.

3. Use Recommended Documentation:

   • Follow guidance from community resources like eLinux.org for porting the MCP2515 module on Orin Nano Devkit with JP6.0GA (R36.3.0).

4. Compile Device Tree Sources:

   • After making modifications, compile your device tree sources using:

     dtc -I dts -O dtb -o <output_file>.dtb <input_file>.dts
     

5. Check Kernel Logs:

   • Use dmesg | grep mcp to check for any error messages related to MCP2515 initialization.

6. Test with Different Configurations:

   • If possible, test with another Jetson Orin Nano board or a different version of JetPack (e.g., JetPack 5) to determine if the issue persists.

7. Update Drivers and Firmware:

   • Ensure that you have the latest drivers installed for your Jetson board and that your firmware is up-to-date.

8. Community Support:

   • Engage with forums and communities such as NVIDIA Developer Forums for additional insights and shared experiences from other users facing similar issues.

9. Document All Changes:

   • Keep a detailed log of all changes made during troubleshooting to help identify what may have resolved or aggravated the issue.

10. Best Practices for Future Prevention:

    • Before making changes, back up your current device tree configurations.
    • Regularly check for updates from NVIDIA regarding JetPack and related documentation.

By following these steps, users should be able to effectively troubleshoot and potentially resolve issues related to enabling the MCP2515 on their Jetson Orin Nano Developer Kit while using L4T 36.3.