CH340 Driver Not Detected on Jetson Orin Nano

Issue Overview

Users of the Nvidia Jetson Orin Nano development board are experiencing difficulties with devices that require the CH340 driver, specifically when trying to use an SBUS to USB converter. The main symptoms include:

• The device is not showing up when running ls /dev/tty*
• The device is visible when using the lsusb command
• The issue occurs on Jetson Orin Nano running kernel version 5.15.136-tegra
• The problem persists even after attempting to manually install the CH340 driver

This issue significantly impacts the functionality of USB devices that rely on the CH340 driver, preventing users from utilizing certain hardware with their Jetson Orin Nano board.

Possible Causes

1. Kernel Version Mismatch: The user attempted to install a driver version (4.4.38-tegra) that does not match the current kernel version (5.15.136-tegra). This incompatibility can prevent the driver from functioning correctly.

2. Incorrect Driver Installation: The manual installation process may not have been executed correctly, or the installed driver may not be compatible with the Jetson Orin Nano’s architecture.

3. Hardware Compatibility Issues: There might be compatibility issues between the specific SBUS to USB converter and the Jetson Orin Nano board.

4. Udev Rules: The system may lack the necessary udev rules to recognize and create device nodes for CH340-based devices.

5. USB Port or Cable Issues: Faulty USB ports or cables could prevent the device from being properly detected by the system.

Troubleshooting Steps, Solutions & Fixes

1. Verify Device Detection:

   • Confirm that the device is detected using lsusb
   • Check kernel logs for any related messages: dmesg | grep -i ch340

2. Install Correct Driver Version:

   • Download the appropriate CH340 driver source for the 5.15.136-tegra kernel
   • Build and install the driver using the following commands:

     make
     sudo make install
     sudo modprobe ch340
     

3. Build Custom Kernel with CH340 Support:

   • Follow the Nvidia documentation to build a custom kernel:
     https://docs.nvidia.com/jetson/archives/r36.3/DeveloperGuide/SD/Kernel/KernelCustomization.html
   • Ensure that the CH340 driver is enabled in the kernel configuration

4. Create Udev Rule:

   • Create a new udev rule file: sudo nano /etc/udev/rules.d/99-ch340.rules
   • Add the following line:

     SUBSYSTEM=="tty", ATTRS{idVendor}=="1a86", ATTRS{idProduct}=="7523", MODE="0666", GROUP="dialout"
     

   • Reload udev rules: sudo udevadm control --reload-rules && sudo udevadm trigger

5. Try Different USB Ports and Cables:

   • Test the device on multiple USB ports
   • Use a high-quality USB cable to rule out connection issues

6. Check for Conflicting Drivers:

   • Unload potentially conflicting drivers:

     sudo modprobe -r ch341 cp210x
     sudo modprobe ch340
     

7. Verify Kernel Module Loading:

   • Check if the module is loaded: lsmod | grep ch340
   • If not loaded, try loading it manually: sudo modprobe ch340

8. Update Jetson Orin Nano Software:

   • Ensure your Jetson Orin Nano is running the latest software version
   • Update the system: sudo apt update && sudo apt upgrade

9. Compile CH340 Driver from Source:

   • Download the latest CH340 driver source from the manufacturer’s website
   • Compile the driver for your specific kernel version:

     make
     sudo make install
     sudo depmod -a
     sudo modprobe ch340
     

10. Consult Nvidia Developer Forums:

    • If the issue persists, consider posting a detailed description of your problem on the official Nvidia Developer Forums for Jetson Orin Nano

Remember to reboot the system after making significant changes to drivers or kernel modules. If none of these solutions resolve the issue, it may be necessary to contact Nvidia support or consider alternative USB-to-SBUS converters that are known to be compatible with the Jetson Orin Nano.