Using I2C Pins as GPIO on Jetson Orin Nano Dev Kit

Issue Overview

Users are experiencing difficulties in configuring the I2C pins on the Nvidia Jetson Orin Nano Dev Kit to function as General Purpose Input/Output (GPIO) due to limitations in the Jetson-io utility. The specific symptoms include:

• Inability to control I2C pins as GPIO, which is critical for tasks requiring high current drive strength.
• The issue arises during the setup phase when attempting to modify pin functionalities.
• Users have referenced the need to either define a device overlay or modify the main device tree file, indicating a lack of straightforward configuration options.
• The problem appears to be consistent among users attempting similar configurations, impacting their ability to utilize the hardware effectively for their projects.

This limitation significantly affects user experience, as it restricts the flexibility and functionality of the Jetson Orin Nano Dev Kit in various applications.

Possible Causes

The challenges faced by users can be attributed to several potential causes:

• Hardware Incompatibilities or Defects: The Jetson Orin Nano may have specific hardware limitations that prevent I2C pins from being repurposed as GPIO.

• Software Bugs or Conflicts: There may be bugs in the Jetson-io utility or conflicts with other software components that hinder proper pin configuration.

• Configuration Errors: Incorrect settings in the device tree or overlays might lead to failures in changing pin functionalities.

• Driver Issues: Outdated or incompatible drivers could prevent the correct operation of I2C pins as GPIO.

• Environmental Factors: External factors such as inadequate power supply could affect pin performance.

• User Errors or Misconfigurations: Users may not be following the correct procedures for modifying pin configurations, leading to unsuccessful attempts.

Each of these causes can contribute to the inability to utilize I2C pins as GPIO, necessitating careful troubleshooting and consideration of potential solutions.

Troubleshooting Steps, Solutions & Fixes

To address the issue of using I2C pins as GPIO on the Jetson Orin Nano Dev Kit, follow these comprehensive troubleshooting steps and potential solutions:

1. Verify Hardware Compatibility:

   • Confirm that your specific model of the Jetson Orin Nano supports reconfiguring I2C pins as GPIO. Refer to official Nvidia documentation for hardware specifications.

2. Check Software Version:

   • Ensure that you are using the latest version of the Jetson Linux SDK. Updates may contain bug fixes related to pin configuration.

3. Use Device Tree Overlays:

   • If you are familiar with device tree modifications, create a custom overlay to define the desired functionality for your I2C pins. This may involve:
     • Writing a new overlay file that specifies pin configurations.
     • Using the dtc command to compile your overlay:

       dtc -I dts -O dtb -o my_overlay.dtbo my_overlay.dts
       

     • Loading your overlay using:

       sudo dtoverlay my_overlay.dtbo
       

4. Modify Main Device Tree File:

   • If overlays do not suffice, consider modifying the main device tree file directly. This is more complex and requires re-flashing your device:
     • Follow guidelines provided in Nvidia documentation for safely modifying and flashing device trees.

5. Re-flash Target if Necessary:

   • As suggested in forum replies, if changes are made to mb1 settings or device trees, ensure you re-flash your target system to apply updates correctly.

6. Test with Different Configurations:

   • Isolate the issue by testing different configurations or setups. For example, try using alternative GPIO pins if available.

7. Gather System Information:

   • Use commands like dmesg and cat /proc/interrupts to gather logs and check for any errors related to pin configuration.

8. Consult Community Resources:

   • Refer to related forum threads (e.g., Topic 245589) for additional insights and user experiences regarding similar issues.

9. Best Practices for Future Prevention:

   • Regularly check for software updates and community discussions about known issues.
   • Document any changes made during configuration processes for future reference.

By following these steps, users should be able to troubleshoot and potentially resolve issues related to using I2C pins as GPIO on their Jetson Orin Nano Dev Kit effectively.