SYSFS GPIO Number of ORIN NANO gpio PCC.03, PX.07 Question

Issue Overview

The discussion centers around users attempting to identify the SYSFS GPIO numbers for specific pins on the Nvidia Jetson Orin Nano Dev board while developing a camera system that utilizes GPIO for zoom control and autofocus motor management.

Symptoms and Context

• Users are unable to determine the SYSFS GPIO numbers for the pins PCC.03 and PX.07.
• The issue arises during the setup phase when users are trying to configure GPIO for their applications.
• Users reference previous experiences with the Jetson Nano, where they successfully used specific GPIO numbers but are unsure how to apply this knowledge to the Orin Nano.
• The problem appears to be consistent among users who are transitioning from the Jetson Nano to the Orin Nano, indicating a potential gap in documentation or understanding of pin configurations.

Hardware and Software Specifications

• Device: Nvidia Jetson Orin Nano Dev Board
• Context: Developing camera applications with GPIO control
• Previous Reference: Users cite successful configurations on Jetson Nano using GPIO06 and UART0_CTS.

Impact on User Experience

The inability to identify the correct SYSFS GPIO numbers can hinder development efforts, leading to delays in project timelines and increased frustration among developers who rely on precise hardware configurations.

Possible Causes

• Documentation Gaps: Insufficient or unclear documentation regarding GPIO mappings for the Orin Nano compared to earlier models like the Jetson Nano.

• Configuration Errors: Users may misinterpret pin configurations due to differences in nomenclature or layout between different Jetson models.

• User Errors: Miscalculations or misunderstandings in determining SYSFS GPIO numbers based on provided pinmux configurations.

Troubleshooting Steps, Solutions & Fixes

Step-by-Step Instructions

1. Refer to Official Documentation:

   • Check the Nvidia documentation specifically for the Jetson AGX Orin platform, focusing on sections related to GPIO configuration and pinmux settings.

2. Calculate SYSFS GPIO Numbers:

   • For PCC.03:
     • Use the formula: $$GPIO3_{PCC.03} = 3(C) * 8 + 3(03) = 27$$
   • For PX.07:
     • Use the formula: $$GPIO3_{PX.07} = 7(X) * 8 + 7(07) = 63$$

3. Utilize Existing Resources:

   • Follow instructions from community discussions or Nvidia’s technical guides such as "Jetson AGX Orin Platform Adaptation and Bring-Up — Identifying the GPIO Number" which provide detailed methodologies for calculating GPIO numbers.

4. Test Configuration:

   • After determining the SYSFS GPIO numbers, test them in your application setup by using commands like:

     echo "27" > /sys/class/gpio/export
     echo "out" > /sys/class/gpio/gpio27/direction
     

5. Cross-reference with Other Users:

   • Engage with community forums or support channels to confirm findings with other developers who have successfully configured similar setups.

Recommended Fixes

• If calculations yield unexpected results, double-check against updated pinmux configuration files provided by Nvidia.

• Ensure that all relevant drivers are up-to-date and compatible with your current setup.

Best Practices

• Always refer to the latest documentation from Nvidia when working with new hardware.

• Maintain a log of configurations and settings used during development for easier troubleshooting in future projects.

Unresolved Aspects

While users have made progress identifying SYSFS GPIO numbers, there remains a need for clearer documentation from Nvidia regarding differences between models and comprehensive examples of common configurations for new developers transitioning from older Jetson boards. Further community engagement may help illuminate these gaps.