Can’t switch GPIO01/PQ.05/105/453/pin-29 to input using /sys/class/gpio

Issue Overview

Users are experiencing difficulties when attempting to configure GPIO01 (PQ.05) on the Nvidia Jetson Orin Nano Dev board as an input. The symptoms include:

• Inability to switch GPIO01 to input mode successfully.
• When the GPIO pin is connected to ground, it reads as 0; however, when disconnected, it continues to read as 0 instead of reverting to a high state.
• Voltage readings indicate potential issues: Vcc to ground shows 3.3V, but Vcc to GPIO01 reads only 2.3V, and GPIO01 to ground shows 1V.

The issue occurs during setup when users are trying to configure the GPIO pin through the /sys/class/gpio interface. Users have confirmed that they are utilizing the Nvidia devkit board and have followed the necessary commands for switching the pin direction. The problem appears consistent across attempts, impacting the user experience by preventing proper input functionality.

Possible Causes

1. Hardware Incompatibilities or Defects: The GPIO pin may be faulty or not functioning as expected due to hardware issues.
2. Software Bugs or Conflicts: There might be bugs within the operating system or drivers that interfere with GPIO configuration.
3. Configuration Errors: Incorrect configuration settings in the pinmux may prevent proper functionality of the GPIO pin.
4. Driver Issues: Outdated or incompatible drivers could lead to improper handling of GPIO operations.
5. Environmental Factors: Issues such as power supply inconsistencies could affect voltage levels at the GPIO pins.
6. User Errors or Misconfigurations: Missteps in command execution or misunderstanding of GPIO handling could lead to this issue.

Troubleshooting Steps, Solutions & Fixes

1. Verify Pinmux Configuration:

   • Ensure that the pinmux settings for PQ.05 are correctly configured.
   • Use the command:

     sudo busybox devmem 0x02430068
     

   • Check if it returns expected values; if not, adjust accordingly.

2. Check for Driver Updates:

   • Ensure that you are using the latest drivers for your Jetson Orin Nano.
   • Update your system using:

     sudo apt-get update && sudo apt-get upgrade
     

3. Test Different Configurations:

   • Try using a different GPIO pin to see if the issue persists.
   • If possible, test with another Jetson Orin Nano board.

4. Inspect Electrical Connections:

   • Double-check all physical connections and ensure that there are no shorts or loose connections.
   • Confirm that pull-up/pull-down resistors are correctly implemented.

5. Use Alternative Commands:

   • Instead of echoing directly into files, consider using a more controlled approach via a script or program that handles GPIO settings.

6. Consult Documentation:

   • Review Nvidia’s official documentation regarding GPIO usage on the Jetson Orin Nano for any missed steps or configurations.

7. Seek Community Support:

   • If unresolved, post detailed findings on forums such as Nvidia Developer Forums for additional insights from other developers who may have faced similar issues.

8. Document Unresolved Issues:

   • Note that while some users reported success with specific configurations, others continue to face challenges, indicating potential underlying issues with either hardware or software that require further investigation.

By following these steps, users can systematically diagnose and potentially resolve the issues faced when configuring GPIO01 on their Jetson Orin Nano Dev board.