OpenThread nRF52840 Firmware Builder

This repository automatically builds the latest version of the OpenThread firmware for the nRF52840 platform. The firmware includes both UART and USB versions, which can be downloaded directly from the Actions tab in this GitHub repository.

Overview

The build process ensures the most up-to-date OpenThread firmware for nRF52840 by leveraging GitHub Actions. Both versions of the firmware (UART and USB) are built and tagged accordingly:

• UART Version: ot-cli-ftd-UART.hex
• USB Version: ot-cli-ftd-USB.hex
• USB Radio Co-Processo: ot-rcp-USB.hex

Firmware is published as part of bi-monthly releases, which include precompiled binaries for different use cases supported versions.

How to Download the Firmware

1. Go to the Releases page.
2. Select the most recent release (release 07/2025 known good).
3. Download the appropriate firmware file for your device and use case from the Assets section.
   • For use with OpenThread Border Router, a Radio Co-Processor (RPC) image is required.

How to Flash the Firmware

USB Version

To flash the USB version (ot-rcp-USB.hex), you can use either the nRF Connect for Desktop application or the nrfjprog command-line tool. Follow the steps below based on your preferred method:

Using nRF Connect for Desktop

1. Download and install nRF Connect for Desktop if not already installed.
2. Launch nRF Connect for Desktop and open the Programmer Tool.
3. Put the nRF52840 dongle into program mode:
   • Insert the dongle into a USB port on your computer.
   • Hold down the reset button while inserting the dongle until the LED blinks rapidly. This indicates the device is in program mode.
4. In the Programmer Tool, select the detected nRF52840 dongle from the device list.
5. Click Add file and choose the ot-rcp-USB.hex file.
6. Ensure the Erase & Write option is selected.
7. Click Write to flash the firmware onto the dongle.

Using nrfjprog

If you prefer using the command-line tool, nrfjprog (part of the nRF Command Line Tools) can also flash the USB firmware.

1. Put the nRF52840 dongle into program mode:

   • Insert the dongle into a USB port.
   • Hold down the reset button while inserting it, until the LED starts blinking rapidly.

2. Flash the USB firmware:

   • Use the following command:

     nrfjprog --program ot-rcp-USB.hex--sectorerase --reset

3. Verify the flashing process:

   • After flashing, the device should start running the new firmware.

Note: The --sectorerase flag ensures only the necessary sectors are erased, preserving the bootloader on the USB dongle.

UART Version

Once you have downloaded the firmware, you can flash it onto your nRF52840 device using nrfjprog (part of the nRF Command Line Tools):

nrfjprog -f nrf52 --chiperase --program ot-cli-ftd-UART.hex --reset

Home Assistant

👉 For Home Assistant setup instructions, check out homeassisten-setup-otbr.md.

License

This repository and the OpenThread firmware are licensed under the BSD 3-Clause License.

Links

• OpenThread Documentation
• nRF52840 Product Page
• nRF Command Line Tools
• nRF Connect for Desktop