Check the USB driver configuration

Oct 13, 2025 by pinkandtrash.com 20 views

Issues Running Application: Troubleshooting Zephyr's OpenThread Coprocessor Sample

When working with embedded systems and IoT applications, issues can arise during the development and testing process. In this article, we will explore the challenges of running the Zephyr's OpenThread coprocessor sample on the ctcc/nrf52840 board. We will delve into the issues of incorrect device name and non-functional serial ports, and provide potential solutions to these problems.

The Zephyr project is an open-source real-time operating system (RTOS) designed for embedded systems. It provides a flexible and scalable platform for developing IoT applications. The OpenThread coprocessor sample is a demonstration of how to use Zephyr to implement a Thread network coprocessor. This sample is designed to run on the ctcc/nrf52840 board, which is a popular development board for IoT applications.

To reproduce the issue, we compiled the zephyr/samples/net/openthread/coprocessor sample using the following command:

west build -b ctcc/nrf52840 samples/net/openthread/coprocessor

We then flashed the compiled firmware using the smpmgr tool:

smpmgr flash

After flashing the firmware, we observed that the ctcc/nrf52840 board shows up as a USB device with an incorrect device name: Bus 003 Device 013: ID 37a1:0100 CTHINGS.CO USB-DEV. This is different from the expected device name, which is usually Nordic Semiconductor ASA Thread Co-Processor or similar.

In addition to the device name issue, we also observed that the board presents two serial ports: /dev/ttyACM0 and /dev/ttyACM1. However, neither of these serial ports work with the smpmgr or otbr-agent tools.

There are several potential causes for these issues:

Device name mismatch: The device name is generated by the USB driver, and it may be possible to configure the driver to use a different name.
Serial port configuration: The serial ports may not be properly configured, or they may be using a different protocol than expected.
Firmware issues: The firmware may be causing the device name and serial port issues.

To troubleshoot these issues, we can follow these steps:

Check the USB driver configuration: We can check the USB driver configuration to see if it is set to use a different device name.
Verify serial port configuration: We can verify that the serial ports are properly configured and using the correct protocol.
Inspect the firmware: We can inspect the firmware to see if it is causing the device name and serial port issues.
Use a serial console tool: We can use a serial console tool, such as screen or minicom, to connect to the serial ports and see if they are working correctly.

In conclusion, the issues of incorrect device name and non-functional serial ports can be challenging to troubleshoot. However, by following the troubleshooting steps outlined above, we can identify the potential causes and resolve the issues. By understanding the potential causes and taking the necessary steps to troubleshoot the issues, we can ensure that our Zephyr-based IoT applications run smoothly and efficiently.

In the future, we can explore the following areas:

Improving the USB driver configuration: We can work on improving the USB driver configuration to ensure that it uses the correct device name.
Enhancing serial port configuration: We can enhance the serial port configuration to ensure that it is properly set up and using the correct protocol.
Optimizing the firmware: We can optimize the firmware to ensure that it is not causing the device name and serial port issues.

By addressing these areas, we can improve the overall performance and reliability of our Zephyr-based IoT applications.
Frequently Asked Questions: Issues Running Application

A: The device name is generated by the USB driver, and it may be possible to configure the driver to use a different name. However, in this case, the device name is being generated by the ctcc/nrf52840 board's USB driver, and it is not clear why it is using the name Bus 003 Device 013: ID 37a1:0100 CTHINGS.CO USB-DEV instead of the expected name Nordic Semiconductor ASA Thread Co-Processor.

A: To troubleshoot the serial port issue, you can follow these steps:

Verify serial port configuration: Check that the serial ports are properly configured and using the correct protocol.
Use a serial console tool: Use a serial console tool, such as screen or minicom, to connect to the serial ports and see if they are working correctly.
Inspect the firmware: Inspect the firmware to see if it is causing the serial port issue.

A: /dev/ttyACM0 and /dev/ttyACM1 are two serial ports presented by the ctcc/nrf52840 board. However, it is not clear why there are two serial ports, and which one is the correct one to use.

A: To configure the USB driver to use a different device name, you will need to modify the USB driver code. However, this is a complex task and requires a good understanding of the USB driver code and the Zephyr operating system.

A: Yes, you can use a different serial console tool, such as screen or minicom, to connect to the serial ports and see if they are working correctly.

A: The best way to troubleshoot the issue is to follow a systematic approach:

Gather information: Gather as much information as possible about the issue, including the device name and serial port configuration.
Verify configuration: Verify that the configuration is correct and that the serial ports are properly configured.
Use a serial console tool: Use a serial console tool to connect to the serial ports and see if they are working correctly.
Inspect the firmware: Inspect the firmware to see if it is causing the issue.

A: Yes, you can get help from the Zephyr community by posting on the Zephyr mailing list or by joining the Zephyr IRC channel. The Zephyr community is very active and helpful, and you can get assistance from experienced developers who have worked on similar issues.

A: After troubleshooting the issue, the next step is to fix the issue and ensure that the device name and serial port configuration are correct. This may involve modifying the USB driver code or the firmware to fix the issue.

In conclusion, troubleshooting the issue of incorrect device name and non-functional serial ports requires a systematic approach and a good understanding of the Zephyr operating system and the USB driver code. By following the troubleshooting steps outlined above, you can identify the potential causes and resolve the issues.