Fan Control Issue on Nvidia Jetson Orin Nano Dev Board

Issue Overview

Users have reported issues with controlling the PWM fan on the Nvidia Jetson Orin Nano Dev Board. The specific symptoms include the fan functioning correctly when using the SDK Manager to flash the SSD but failing to operate when compiling and flashing the source code manually. This issue has been observed with the operating system version Jetson Linux 35.3.1. Users have attempted to control the fan via GPIO14 configured for PWM but have encountered inconsistent behavior. The problem arises during the setup phase when users try to compile their own source code, leading to frustration and a negative impact on the user experience as it hinders expected functionality.

Possible Causes

1. Configuration Errors: Misconfigurations in the source code or incorrect GPIO settings could prevent proper PWM signal generation for fan control.
2. Source Code Modifications: Users have indicated that modifications made to the source code could inadvertently disrupt functionality, particularly if custom driver modules are added without proper integration.
3. Driver Issues: Incompatibilities or bugs in the drivers used for PWM control may lead to failures in fan operation.
4. Hardware Limitations: The specific hardware setup, including whether an official Nvidia carrier board is used, may affect compatibility and functionality.
5. Environmental Factors: Power supply issues or overheating could also contribute to erratic behavior of connected peripherals like fans.

Troubleshooting Steps, Solutions & Fixes

1. Verify GPIO Configuration:

   • Ensure that GPIO14 is correctly configured for PWM output in your source code.
   • Use commands such as echo "14" > /sys/class/gpio/export followed by echo "out" > /sys/class/gpio/gpio14/direction to set up GPIO14.

2. Check Source Code Compilation:

   • Revisit the compilation steps for your source code. Make sure you are following NVIDIA’s guidelines for kernel customization as outlined in their official documentation Kernel Customization Guide.
   • If custom driver modules were added, consider removing them temporarily to see if fan control is restored.

3. Recompile with Clean Source:

   • If modifications were made to the source code, download a fresh copy of the source code and recompile without changes to rule out errors introduced by previous modifications.

4. Use SDK Manager for Flashing:

   • As a workaround, use the SDK Manager for flashing instead of manual compilation if possible, as it has been confirmed to work correctly with fan control.

5. Inspect Power Supply:

   • Ensure that your power supply meets the requirements for the Orin Nano Dev Board and that there are no voltage drops that could affect peripheral operations.

6. Testing with Different Configurations:

   • Test with different versions of Jetson Linux (if available) or revert back to a stable version known to work with fan control.
   • If possible, try using an official Nvidia carrier board instead of third-party boards which may have compatibility issues.

7. Documentation and Community Support:

   • Refer to NVIDIA forums and community discussions for additional insights or similar issues faced by other users NVIDIA Developer Forums.

8. Log and Report Errors:

   • If issues persist, gather logs from your system using commands like dmesg and report them on forums for further assistance from NVIDIA support or community experts.

By following these steps, users should be able to diagnose and potentially resolve issues related to PWM fan control on their Nvidia Jetson Orin Nano Dev Boards effectively.