Jetson Orin Nano Developer Kit Can’t Use I2C0 or I2C1

Issue Overview

Users of the Jetson Orin Nano Developer Kit are experiencing difficulties in utilizing the I2C0 and I2C1 interfaces. Specifically, when attempting to communicate with these interfaces using the iic-tools, no signals are detected by a logic analyzer, indicating a potential failure in the I2C communication. The problem occurs while running commands such as i2cdetect -y 0 and i2cset -f -y 1 0x51 0x00 0xff, which are standard for detecting and setting I2C devices.

The issue arises with the 5.1.1 version of the SD card image, suggesting that it may be related to either software or hardware configurations. Users have reported that no signals are captured on the logic analyzer despite proper command execution, leading to frustration and a significant impact on their ability to interface with I2C devices.

Possible Causes

• Hardware Incompatibilities or Defects: There may be issues with the physical connections or defects in the Jetson Orin Nano board itself, affecting the I2C interfaces.

• Software Bugs or Conflicts: The version of the SD card image (5.1.1) may contain bugs that impact I2C functionality or conflicts with other software components.

• Configuration Errors: Incorrect configuration settings for I2C interfaces could prevent proper communication.

• Driver Issues: Outdated or incorrect drivers for I2C communication might lead to failures in detecting or sending signals.

• Environmental Factors: Issues such as insufficient power supply or temperature extremes could affect hardware performance.

• User Errors or Misconfigurations: Misunderstandings regarding pin assignments or command usage may lead users to incorrectly set up their devices.

Troubleshooting Steps, Solutions & Fixes

1. Verify Pin Assignments:

   • Confirm that the correct pins are being used for I2C0 and I2C1. According to user discussions, pin assignments may differ from expectations (e.g., pin 3 and 5 correspond to i2c7 bus instead of iic1).

   # Check pin assignments
   cat /sys/class/i2c-dev/i2c-0/device/uevent
   

2. Check Device Tree Configuration:

   • Ensure that the device tree is correctly configured for I2C interfaces. This can be done by checking the relevant device tree source files.

3. Test with iic-tools:

   • Run commands to detect devices on both I2C buses:

   i2cdetect -y 0
   i2cdetect -y 1
   

4. Use Logic Analyzer:

   • If possible, connect a logic analyzer to monitor signals on the relevant pins while executing commands to see if any data is transmitted.

5. Update Software and Drivers:

   • Ensure that you are using the latest version of the SD card image and any associated drivers. Check Nvidia’s official documentation for updates.

6. Power Supply Check:

   • Verify that your power supply meets the required specifications for the Jetson Orin Nano Developer Kit.

7. Consult Documentation:

   • Review Nvidia’s official documentation for any specific instructions regarding I2C setup and troubleshooting.

8. Seek Community Support:

   • If issues persist, consider posting detailed information about your setup on forums or reaching out to Nvidia support for assistance.

9. Recommended Approach:

   • Many users have found success by double-checking pin assignments and ensuring they align with what is expected in the documentation, as well as updating their software environment regularly.

10. Unresolved Aspects:

    • Some users noted discrepancies in pin mappings and device tree configurations that remain unaddressed, suggesting further investigation into these areas may be necessary for a comprehensive solution.