Troubleshooting CAN Communication Issues on Jetson AGX Orin Developer Kit

Issue Overview

Users of the NVIDIA Jetson AGX Orin Developer Kit are experiencing problems with CAN (Controller Area Network) communication. Specifically, the issue involves:

• Inability to read and send signals to motors via CAN
• CAN transceivers running off 3.3V pins (1, 17)
• The problem arose after making wiring changes
• SSH access and command sending still work, but no CAN information is visible
• Concerns about potential voltage or amperage draw issues affecting the Orin

The issue impacts the functionality of motor control and CAN-based communication, which are critical for many robotics and automotive applications.

Possible Causes

1. Wiring errors: Incorrect connections made during recent wiring changes could have led to improper signal routing or power distribution.

2. Voltage/current overload: Excessive voltage or current draw might have damaged the CAN interface or related components.

3. Software configuration issues: Changes in the system setup or Jetpack version could affect CAN functionality.

4. Hardware damage: There’s a possibility that the Orin’s CAN interface or related pins were damaged due to electrical issues.

5. Driver problems: CAN drivers might have been corrupted or misconfigured during system changes.

6. Transceiver malfunction: The CAN transceivers themselves could be faulty or damaged.

Troubleshooting Steps, Solutions & Fixes

1. Verify Jetpack version:

   • Check the current Jetpack version using the command:

     cat /etc/nv_tegra_release
     

   • Ensure it’s compatible with your hardware and software requirements.

2. Inspect wiring:

   • Double-check all connections, especially those related to CAN and power.
   • Ensure proper grounding and that no shorts exist between pins.

3. Test CAN interface:

   • Use the following commands to check if the CAN interface is recognized:

     ip link show
     sudo ip link set can0 up type can bitrate 500000
     candump can0
     

   • If the interface is not listed, it may indicate a hardware or driver issue.

4. Check system logs:

   • Examine dmesg logs for any CAN-related errors:

     dmesg | grep -i can
     

   • Look for any error messages or warnings related to CAN initialization or communication.

5. Verify CAN driver status:

   • Check if the CAN driver is loaded:

     lsmod | grep can
     

   • If not present, try loading it manually:

     sudo modprobe can
     sudo modprobe can_raw
     

6. Test with a different CAN transceiver:

   • If available, connect a known working CAN transceiver to isolate whether the issue is with the Orin or the external hardware.

7. Measure voltage levels:

   • Use a multimeter to check the voltage on the 3.3V pins (1, 17) to ensure they’re providing the correct voltage.
   • Measure the voltage on the CAN pins to verify proper signal levels.

8. Create a connection diagram:

   • Draw a detailed block diagram of your CAN setup, including all connections, transceivers, and motors.
   • Share this diagram with NVIDIA support or community forums for more specific advice.

9. Perform a loopback test:

   • Connect CAN_H and CAN_L pins together to create a loopback.
   • Use canutils to send and receive messages:

     cansend can0 123#DEADBEEF
     candump can0
     

   • This can help determine if the issue is with the Orin’s CAN interface or external components.

10. Consider a clean install:

    • If software issues are suspected, consider reflashing the Jetson with the latest Jetpack version.
    • Follow the official NVIDIA documentation for flashing instructions.

11. Contact NVIDIA Support:

    • If the issue persists after trying these steps, contact NVIDIA support with:
      • Your Jetpack version
      • The full dmesg log
      • Your connection block diagram
      • A detailed description of the troubleshooting steps you’ve taken

Remember to exercise caution when working with electrical components and follow proper ESD (Electrostatic Discharge) precautions to avoid further damage to the Jetson AGX Orin Developer Kit.