Configuring PWM on Jetson Orin Nano Developer Kit

Issue Overview

Users are encountering difficulties in configuring Pulse Width Modulation (PWM) on the Jetson Orin Nano Developer Kit, specifically regarding how to set up pinmux to enable PWM functionality on GPIO pins. Despite checking the L4T documentation, users find limited information related to the Orin Nano. The primary goal is to configure a GPIO pin for PWM output using the Nvidia GPIO library, but users are unsure of the correct procedures or configurations required.

Specific Symptoms

• Inability to successfully configure PWM on specified GPIO pins.
• Lack of clear guidance in available documentation regarding pinmux configuration for the Orin Nano.
• Users seeking advice on enabling PWM signals through the Nvidia GPIO library.

Context

The issue arises during development efforts aimed at utilizing PWM signals for various applications. Users are specifically interested in modifying pinmux settings to allow PWM signals to be generated from GPIO pins, which is crucial for controlling external devices.

Hardware/Software Specifications

• Hardware: Nvidia Jetson Orin Nano Developer Kit
• Software: JetPack (specific version not mentioned), Nvidia GPIO library

Frequency of Issue

This issue appears to be common among developers working with the Jetson Orin Nano, indicating a potential gap in documentation or support for configuring PWM on this hardware.

Impact on User Experience

The inability to configure PWM correctly can hinder project development and limit the functionality of applications that rely on precise timing and control of external devices.

Possible Causes

1. Insufficient Documentation: The L4T documentation may not provide adequate details specifically for the Orin Nano, leading to confusion about configuration steps.

   • Explanation: Without clear instructions, users may struggle to identify the correct procedures for setting up PWM.

2. Driver Compatibility Issues: The Nvidia GPIO library may not fully support PWM functionality on all pins of the Orin Nano.

   • Explanation: If certain pins are not configured correctly or are incompatible with the library, PWM outputs may fail.

3. Incorrect Pinmux Configuration: Users may not be aware of how to properly configure pinmux settings for enabling PWM on specific GPIO pins.

   • Explanation: If pinmux settings are incorrect, PWM signals may not be routed properly to the desired pins.

4. Hardware Limitations: There could be inherent limitations in the hardware design that restrict certain pins from being used for PWM output.

   • Explanation: Not all GPIO pins may support PWM functionality due to hardware constraints.

Troubleshooting Steps, Solutions & Fixes

1. Refer to Existing Threads:

   • Check community threads related to enabling PWM on similar devices (e.g., Xavier NX) for guidance and potential solutions:
     • Example thread: "How to use PWM on Xavier NX" [Nvidia Developer Forums].

2. Use Jetson-IO Tool:

   • Utilize the Jetson-IO tool to configure pinmux settings:

     sudo /opt/nvidia/jetson-io/jetson-io.py
     

   • Follow prompts to manually configure header pins for PWM output as needed.

3. Install Necessary Libraries:

   • Ensure that you have installed the Nvidia GPIO library and any dependencies:

     sudo apt update
     sudo apt install git python3-pip pip
     git clone https://github.com/NVIDIA/jetson-gpio.git
     cd jetson-gpio
     sudo python3 setup.py install
     

4. Test PWM Functionality:

   • After configuring pinmux, test PWM functionality using sample scripts provided in the Nvidia GPIO repository:

     cd samples
     sudo python simple_pwm.py  # Ensure this script uses the correct pin configured for PWM.
     

5. Check Sysfs Entries:

   • Verify if the configured pins appear in sysfs and check their status:

     ls /sys/class/pwm/
     

6. Consult Community Resources:

   • Engage with forums or community discussions focused on Nvidia Jetson products for shared experiences and solutions from other users facing similar challenges.

7. Document Configuration Steps:

   • Keep a record of all changes made during configuration attempts for easier troubleshooting in future projects.

8. Monitor Updates from Nvidia:

   • Stay informed about any new releases or updates from Nvidia regarding driver support and modifications that may enhance capabilities for the Jetson Orin Nano.

9. Unresolved Aspects:

   • Further investigation may be needed regarding specific limitations of using certain GPIO pins for PWM.
   • Users should continue sharing their experiences and insights in community forums to build a collective knowledge base around this issue.

By following these troubleshooting steps, users should be able to better navigate challenges related to configuring PWM on their Nvidia Jetson Orin Nano devices effectively.