GPIO Pull High/Low Issues on Nvidia Jetson Orin Nano Dev Board

Issue Overview

Users of the Nvidia Jetson Orin Nano Dev board have reported issues related to the GPIO (General Purpose Input/Output) pins, specifically when using IR (Infrared) switches connected to GPIO09 and GPIO13. The primary symptoms include:

• GPIO Read Values: When the IR switches are activated, the GPIO read values consistently return as 0, indicating that the expected high signal is not being registered.

• Context of the Problem: This issue arises during the setup and testing of IR switches, suggesting a potential misconfiguration or hardware incompatibility.

• Hardware Specifications: The discussion mentions using the Nvidia Orin Nano 4G development board with specific GPIO pins.

• Frequency of Occurrence: The problem appears to be consistent among users who have configured similar setups.

• Impact on User Experience: The inability to read correct values from GPIO pins hampers functionality and limits the use of connected peripherals, leading to frustration among users.

• Relevant Context: Users are questioning whether internal pull-up or pull-down resistors are affecting the GPIO readings and are seeking methods to disable these resistors.

Possible Causes

Several potential causes for the observed issue have been identified:

• Hardware Incompatibilities or Defects: Incorrect wiring or defective GPIO pins could lead to erroneous readings.

• Software Bugs or Conflicts: There may be bugs in the software or conflicts with other applications that affect GPIO functionality.

• Configuration Errors: Incorrect pinmux settings could prevent proper configuration of pull-up or pull-down resistors.

• Driver Issues: Outdated or incompatible drivers may not support the desired GPIO configurations.

• Environmental Factors: Power supply issues or temperature variations could affect GPIO performance.

• User Errors or Misconfigurations: Misunderstanding of how to configure GPIO settings might lead to incorrect setups.

Troubleshooting Steps, Solutions & Fixes

To address the issue with GPIO pull high/low settings on the Nvidia Jetson Orin Nano, users can follow these troubleshooting steps:

1. Check Wiring Connections:

   • Ensure that IR switches are correctly connected to GPIO09 and GPIO13.
   • Verify that there are no loose connections or shorts in the circuit.

2. Update Pinmux Configuration:

   • Modify the pinmux configuration by generating updated .dtsi files.
   • Refer to documentation on generating pinmux dtsi files for guidance.

3. Configure Pull-Up/Pull-Down Settings:

   • Adjust settings in the pinmux configuration to specify either internal pull-up (Int PU) or internal pull-down (Int PD) resistors based on your application needs.
   • Review and edit the created pinmux.dtsi file and gpio.dtsi file for proper pin definitions.

4. Verify Driver Installation:

   • Ensure that all necessary drivers for GPIO functionality are installed and up-to-date.
   • Use terminal commands to check driver versions and update if necessary.

5. Test with Different Configurations:

   • If possible, test with different GPIO pins or alternative hardware configurations to isolate the issue.
   • Experiment with different resistor configurations (external pull-up/down) if internal settings do not yield results.

6. Gather System Information:

   • Use commands such as cat /sys/class/gpio/gpioX/value (replace X with your GPIO number) to monitor real-time values from GPIO pins.
   • Check system logs for any error messages related to GPIO operations.

7. Consult Documentation and Community Forums:

   • Refer to Nvidia’s official documentation for additional insights on GPIO configuration.
   • Engage with community forums for shared experiences and solutions from other users facing similar issues.

8. Best Practices for Future Prevention:

   • Always back up current configurations before making changes.
   • Document any modifications made to pinmux settings for future reference.
   • Regularly check for firmware updates that may address known issues with GPIO functionality.

By following these steps, users should be able to diagnose and potentially resolve issues related to GPIO readings on their Nvidia Jetson Orin Nano Dev board. If problems persist, further investigation may be required into specific hardware components or deeper software conflicts.