In this Codelab, you will learn how to build an Radio CoProcess for an OpenThread Border Router on a Raspberry Pi. OpenThread is an open-source implementation of the Thread networking protocol, designed for low-power IoT devices

What You'll Build

In this codelab, you will:

• Build the Radio Co-Processor for NRF52840 dongle on a Raspberry Pi.
• Learn about the concept of a radio co processor

What You'll Learn

• What you will need (Pre-requisities)
• How to clone radio co processor code
• What prerequisites are required for the Raspberry Pi
• How to build the radio co processor on the Raspberry Pi

Before you begin, ensure you have the following:

• A Thread Radio Co-Processor (NRF52840 dongle)
• A Raspberry Pi (preferably a Raspberry Pi 3 or later)
• A microSD card (16GB or larger) with Raspberry Pi OS installed
• A power supply for the Raspberry Pi
• Internet connection for the Raspberry Pi
• Basic knowledge of using the terminal and SSH

The total codelab will take approximately a Duration of 30 minuates to complete.

In this example we are using the nRF52840 USB Dongle

The dongle may come pre-loaded with the older NCP firmware, so first we need to update it to the latest version with the RCP firmware. This required fetching the source and building on a laptop, then flashing the dongle.

1. Clone the OpenThread nRF528xx platform repository into the current directory:

git clone --recursive https://github.com/openthread/ot-nrf528xx.git

Enter the ot-nrf528xx directory:

cd ot-nrf528xx

2. Install OpenThread dependencies:

./script/bootstrap

3. Build OpenThread for the nRF52840 Dongle:

script/build nrf52840 USB_trans -DOT_BOOTLOADER=USB -DOT_THREAD_VERSION=1.2

This creates an RCP image at build/bin/ot-rcp.

4. Convert the RCP image to the .hex format:

cd buiLd/bin
arm-none-eabi-objcopy -O ihex ot-rcp ot-rcp.hex

5. Install NRFUtil

apt-get -y install libusb-1.0-0-dev python3 python3-pip sed
    pip3 install click crcmod ecdsa intelhex libusb1 piccata protobuf
    pip3 install pyserial pyyaml tqdm pc_ble_driver_py pyspinel
    pip3 install --no-dependencies nrfutil==6.1.7

This installs the utility that allows for flashing the NRF dongle

5. Generate the package

$ nrfutil pkg generate \
    --hw-version 52 \
    --sd-req 0x00 \
    --application-version 1 \
    --application ot-rcp.hex \
    app.zip

5. Flash the dongle

To put the dongle into flash mode press the reset button and when you release the red LED will glow.

$ nrfutil dfu usb-serial \
    -pkg app.zip \
    -p /dev/ttyACM0

Once the nRF52840 Radio Co-Processor is ready, you can now prepare the Raspberry Pi as an Open Thread Border Router.

1. Install dependencies:

If you havent already install the dependencies, open the terminal and execute:

sudo apt-get install git cmake make gcc g++ autoconf libtool libssl-dev

2. Clone the OpenThread Border Router repository:

Run the following commands:

git clone https://github.com/openthread/ot-br-posix.git
cd ot-br-posix

3. Install and configure OpenThread:

Follow the instructions to download the code and the run the bootstrap, which will download all the necessary dependencies, packages and tools (may take a while).

./script/bootstrap

Finally, run the OTBR setup (eth0 is my LAN connection; you can also use WiFi). I also enabled the Web GUI for evaluation, although it has no security authentication so I would not recommend running it on a real system.

INFRA_IF_NAME=eth0 WEB_GUI=1 ./script/setup

After setup you can check no errors were reported on the screen, plug in the Radio Co-Processor dongle, and then reboot with

sudo shutdown -r now

Checkout the official documentation here: Project Chip - ConnectedHomeIp