How to Enable CAN ISOTP in Jetson Orin Nano L4T R35_v3.1

Issue Overview

Users are experiencing difficulties enabling the CAN ISOTP protocol on the Jetson Orin Nano Developer Kit running L4T R35_v3.1. The specific symptoms include the absence of the can-isotp.ko kernel module, which is necessary for the CAN transport protocol to function correctly. This issue arises during attempts to set up CAN communication, particularly when users try to implement the CAN protocol as outlined in various guides. The problem appears to be consistent across different setups, indicating a potential oversight in the kernel configuration for this version of L4T. The impact on user experience is significant, as it prevents effective communication over the CAN bus, thereby limiting the functionality of applications relying on this protocol.

Possible Causes

• Kernel Configuration: The CONFIG_CAN_ISOTP setting in the kernel defconfig may not be enabled, preventing the can-isotp.ko module from being compiled and included.
• Missing Module: The absence of the can-isotp.ko module in L4T R35_v3.1 suggests that it was not included in this kernel version by default.
• User Error: Users may not be familiar with kernel rebuilding processes or may overlook necessary configuration steps.
• Software Bugs: There could be bugs or conflicts within the L4T version that affect module loading or availability.

Troubleshooting Steps, Solutions & Fixes

1. Check Kernel Configuration:

   • Access the kernel configuration file (defconfig) for your Jetson Orin Nano.
   • Look for the line containing CONFIG_CAN_ISOTP.
   • If it is not present, you will need to enable it.

   make menuconfig
   

   Navigate to Device Drivers > Network device support > CAN bus subsystem support and enable CONFIG_CAN_ISOTP.

2. Rebuild the Kernel:

   • After enabling CONFIG_CAN_ISOTP, rebuild the kernel to include this module.
   • Use the following commands:

   make
   sudo make modules_install
   sudo make install
   

3. Load the Module:

   • Once rebuilt, load the new module using:

   sudo modprobe can-isotp
   

4. Verify Module Installation:

   • Check if the module is loaded successfully:

   lsmod | grep can_isotp
   

5. Testing CAN Communication:

   • Ensure that your CAN hardware is correctly connected and configured.
   • Use tools like can-utils to test communication:

   cansend can0 123#deadbeef
   

6. Documentation and Updates:

   • Regularly check NVIDIA’s official documentation for updates regarding kernel modules and configurations.
   • Consider using JetPack 5 if issues persist with JetPack 6, as it is more stable for initial setups.

7. Community Support:

   • Engage with forums and community discussions for additional insights and shared experiences from other users who faced similar issues.

8. Best Practices:

   • Always backup your current kernel configuration before making changes.
   • Document any changes made during troubleshooting for future reference.

By following these steps, users should be able to successfully enable CAN ISOTP on their Jetson Orin Nano Developer Kit and resolve related issues effectively.