GPIO Interrupt not working on Jetpack 6

Issue Overview

Users are experiencing difficulties capturing interrupt signals on the Nvidia Jetson Orin Nano Dev board while using Jetpack 6. The main symptoms include:

• Successful configuration of GPIO pins as outputs, but failure to detect interrupts when configured as inputs.
• Users have attempted to use both the libgpiod library in C and the Jetson.GPIO library in Python without success.
• The issue arises specifically under Jetpack 6, where access to SYSFS (i.e., /sys/class/gpio/) has been removed, complicating traditional GPIO management.

The context of this problem typically occurs during setup or when trying to run applications that rely on GPIO interrupts. Users have validated their GPIO configurations using the gpioinfo command, confirming that the pins are set correctly. However, despite these checks, the interrupt signals are not being detected. This issue appears to be consistent among multiple users and significantly impacts their ability to utilize GPIO functionality effectively.

Possible Causes

Several potential causes for this issue have been identified:

• Hardware Incompatibilities or Defects: There may be differences in hardware implementation between the Jetson Nano and Orin Nano that affect interrupt handling.

• Software Bugs or Conflicts: The removal of SYSFS access and changes in library support could introduce bugs or conflicts in handling GPIO interrupts.

• Configuration Errors: If the GPIO pins are not correctly set as inputs using the pinmux spreadsheet, they will not function as intended.

• Driver Issues: The drivers associated with GPIO management may not be fully compatible with Jetpack 6 or may require updates.

• User Errors or Misconfigurations: Users may not be following the correct procedures for setting up GPIO pins, particularly regarding pinmux settings.

Troubleshooting Steps, Solutions & Fixes

To address the issue of GPIO interrupts not working on the Jetson Orin Nano Dev board, follow these troubleshooting steps:

1. Verify Output Functionality:

   • Confirm that you can control high/low output values for the specific GPIO pin using either C with libgpiod or Python with Jetson.GPIO.

2. Check Pin Configuration:

   • Ensure that the desired GPIO pin is set as an input in the pinmux spreadsheet. This is crucial because without proper configuration, the pin will not detect interrupts.

3. Utilize Pinmux Spreadsheet:

   • Access and utilize the pinmux spreadsheet provided by Nvidia to configure your GPIO pins correctly. Avoid direct modifications to the device tree for pinmux settings.
   • For guidance on using the pinmux spreadsheet, refer to Nvidia’s documentation on loading generated files.

4. Testing Configuration:

   • After configuring the pins via the pinmux spreadsheet, reboot your device and test if you can now capture interrupts.

5. Review Documentation:

   • Consult Nvidia’s official documentation for Jetpack 6 and any updates regarding GPIO management practices:
     • Nvidia Developer Guide

6. Update Drivers and Libraries:

   • Ensure that you are using the latest versions of libgpiod and Jetson.GPIO. Check for any available updates that might address known issues with interrupt handling.

7. Best Practices:

   • Always follow Nvidia’s recommended practices for GPIO configuration and management to avoid potential issues in future projects.

8. Further Investigation:

   • If issues persist after following these steps, consider reaching out to Nvidia support or community forums for additional assistance and troubleshooting specific to your setup.

By systematically following these steps, users should be able to diagnose and potentially resolve issues related to GPIO interrupt functionality on their Nvidia Jetson Orin Nano Dev board under Jetpack 6.