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Thread: Co-processor

Overview

The Thread Co-processor sample demonstrates how to implement OpenThread’s Co-processor designs inside the Zephyr environment. The sample uses the Radio co-processor (RCP) architecture.

The sample is based on Zephyr’s OpenThread co-processor sample. However, it customizes Zephyr’s sample to fulfill the nRF Connect SDK requirements (for example, by increasing the stack size dedicated for the user application), and also extends it with features such as:

  • Increased Mbed TLS heap size.
  • Lowered main stack size to increase user application space.
  • No obsolete configuration options.
  • Vendor hooks for co-processor architecture allowing users to extend handled properties by their own, customized functionalities.
  • Thread 1.2 features.

Requirements

Before you start, check that you have the required hardware and software:

  • 1x nRF54L15 Connect Kit
  • 1x U.FL cabled 2.4 GHz Antenna (included in the box)
  • 1x USB-C Cable
  • A computer running macOS, Ubuntu, or Windows 10 or newer

Attaching the 2.4 GHz antenna

Before applying power to the board, ensure the U.FL cabled 2.4 GHz antenna is properly installed.

Building the sample

To build the sample, follow the instructions in Getting Started Guide to set up your preferred building environment.

Use the following steps to build the Thread Co-processor sample on the command line.

  1. Open a terminal window.

  2. Go to NCS-Project/nrf54l15-connectkit repository cloned in the Getting Started Guide.

  3. Build the sample using the west build command, specifying the board (following the -b option) as nrf54l15_connectkit/nrf54l15/cpuapp.

    west build -p always -b nrf54l15_connectkit/nrf54l15/cpuapp samples/openthread/coprocessor

    west build -p always -b nrf54l15_connectkit/nrf54l15/cpuapp samples/openthread/coprocessor -- -DSNIPPET="ci;logging;vendor_hook"

    Tip

    The -p always option forces a pristine build, and is recommended for new users. Users may also use the -p auto option, which will use heuristics to determine if a pristine build is required, such as when building another sample.

  4. After building the sample successfully, the firmware with the name merged.hex can be found in the build directory.

Flashing the firmware

Connect the nRF54L15 Connect Kit to the computer with a USB-C cable:

Then flash the sample using west flash:

west flash

Tip

In case you wonder, the west flash will execute the following command:

pyocd load --target nrf54l --frequency 4000000 build/merged.hex

Testing

After programming the sample, test it by performing the following steps:

  1. Connect the board to your computer using the USB-C Cable.

  2. Get the primary COM port that your computer uses to communicate with the nRF54L15 (e.g., /dev/cu.usbmodem14502).

  3. Build the OpenThread POSIX applications by performing the following steps:

    1. Enter the openthread directory:

      1
      cd modules/lib/openthread

    2. Install the OpenThread dependencies:

      2
      ./script/bootstrap

    3. Build the applications with the required options. For example, to build the ot-cli application, run the following command:

      3
      ./script/cmake-build posix

      Alternatively, to build the ot-daemon and ot-ctl applications, run the following command:

      3
      ./script/cmake-build posix -DOT_DAEMON=ON

    You can find the generated applications in ./build/posix/src/posix/.

  4. Use the following radio URL parameter to connect to the board:

    'spinel+hdlc+uart://\ *ncp_uart_device*\ ?uart-baudrate=\ *baud_rate*' -B *backbone_link*

    Replace the following parameters:

    • ncp_uart_device - Specifies the location of the device, for example: /dev/cu.usbmodem14502.
    • baud_rate - Specifies the baud rate to use. The Thread Co-Processor sample supports baud rate 1000000.
    • backbone_link - Specifies Backbone link for communication with external network. This parameter can be omitted.
    sudo ./build/posix/src/posix/ot-cli 'spinel+hdlc+uart:///dev/cu.usbmodem14502?uart-baudrate=1000000' --verbose -B eth0

    sudo ./build/posix/src/posix/ot-daemon 'spinel+hdlc+uart:///dev/cu.usbmodem14502?uart-baudrate=1000000' --verbose -B eth0

    And on a separate terminal window, specifying the Thread interface utun4 shown in ot-daemon log output:

    sudo ./build/posix/src/posix/ot-ctl -I utun4

  5. From this point, you can follow the Testing instructions in the CLI sample by removing the ot prefix for each command.