Pinmux Functionality on Jetson Orin Nano

Issue Overview

Users have reported difficulties in utilizing the pin multiplexing (Pinmux) functionality on the Nvidia Jetson Orin Nano Dev board. The main symptoms include confusion regarding the secondary assignments of SODIMM pins, specifically concerning their use as General Purpose Input/Output (GPIO) pins. Users are experiencing challenges during setup and configuration, particularly when attempting to implement the generated device tree source (dts) files in the Linux operating system to activate these functionalities.

Key details include:

• Context: Issues arise during the configuration of GPIOs from the Pinmux spreadsheet and while installing JetPack 6 on devices without SD card support.

• Hardware Specifications: Users mention using the Seeed Studio reComputer J3010 Orin Nano 4 devkit, with some considering custom board development.

• Software Specifications: The primary software in question is JetPack 6, which is currently being installed on an NVMe SSD.

• Frequency of Issue: The problem appears to be consistent among users trying to configure GPIOs from the Pinmux spreadsheet.

• Impact: These issues hinder users’ ability to fully utilize the Orin Nano’s capabilities, affecting project timelines and functionality.

Possible Causes

The issues experienced may stem from several potential causes:

• Hardware Incompatibilities: Using different boards (devkit vs. custom) may lead to discrepancies in GPIO functionality.

• Software Bugs or Conflicts: Issues with JetPack 6 installation or compatibility with existing hardware could lead to configuration problems.

• Configuration Errors: Incorrect settings in the Pinmux spreadsheet or misunderstandings about pin assignments may result in non-functional GPIOs.

• Driver Issues: Conflicts with existing drivers or unavailability of required drivers for specific GPIO functions could prevent proper operation.

• Environmental Factors: Power supply inconsistencies or temperature issues may affect board performance.

• User Errors or Misconfigurations: Lack of clarity in documentation may lead users to misconfigure settings or overlook critical steps in the setup process.

Troubleshooting Steps, Solutions & Fixes

To resolve the issues related to Pinmux functionality on the Jetson Orin Nano, follow these comprehensive troubleshooting steps:

1. Verify Hardware Setup:

   • Confirm that you are using the correct board (devkit vs. custom).
   • Ensure all connections are secure and that power supply meets specifications.

2. Check Software Version:

   • Verify that you are using JetPack 6. If not, consider updating to ensure compatibility with your hardware.
   • Use the command:

     dpkg -l | grep nvidia
     

3. Consult Documentation:

   • Review the "Jetson_Orin_NX_series_and_Orin_Nano_series_Pinmux_Config_Template.xlsm" spreadsheet for pin assignments.
   • Refer to "Generating the Pinmux dtsi Files" documentation for guidance on using the spreadsheet effectively.

4. Configuration Validation:

   • Confirm that no other functions or drivers are using the GPIO pins intended for your application.
   • Use commands like cat /proc/interrupts to check if any GPIOs are already assigned.

5. Implement Device Tree Source (DTS) Files:

   • Follow detailed instructions from relevant documentation on how to implement and flash dts files.
   • Example command for flashing:

     sudo ./flash.sh <board> <rootfs>
     

6. Testing GPIO Functionality:

   • After configuring, test GPIO functionality using simple scripts or commands to toggle pin states.
   • Example command for testing:

     echo "1" > /sys/class/gpio/gpio<GPIO_NUMBER>/value
     

7. Seek Community Support:

   • If issues persist, consider posting detailed queries in forums or seeking help from Nvidia support channels.

8. Best Practices for Future Use:

   • Always refer to updated documentation before making changes.
   • Keep your software and drivers up-to-date to avoid compatibility issues.
   • Document any changes made during configuration for future reference.

By following these steps, users should be able to diagnose and potentially resolve issues with Pinmux functionality on their Jetson Orin Nano boards effectively.