Nordic Thingy91 - hello world, built with VScode, programmed via USB (MCUboot)

This posts summarises how you can run the hello world sample on the Nordic Thingy91. I had to do some special things because I do not have a programmer. So I had to program the hello word sample via MCUboot.

Installing

I assume that MCUboot is already programmed on your Thingy91.

First you have to install all necessary software as nRF Connect for Desktop (see Nordic documentation https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/gs_assistant.html)

Easiest way - GUI

The easiest way should be to

  • install “nRF connect for Desktop”
  • from within “nRF connect for Deskop” install “Toolchain manager”
  • from within “Toolchain manager” install “nRF connect SDK”
  • from the latter you should be able to configure VScode with the necessary plugins

On Ubuntu 20.0 I could not get everything working; VScode does work with the plugins, but complaints that it cannot find the “Nrf command line tools” unless they are installed. I ended up with

  • Using VScode for developing the application, only.
  • Flashing is done via “nRF Connect for Desktop” and then starting the “Programmer”; see below.
  • Installing Connect for Desktop
    • Download the Appimage for linux; could not install version 3.12 (gave error about graphics driver); Solution was to install version 3.9, and let it upgrade itself

Install via command line (Ubuntu)

Installing via the command line is also easy, at least if you know the exact commands. These are summarized below:

sudo apt update
sudo apt upgrade

wget https://apt.kitware.com/kitware-archive.sh
sudo bash kitware-archive.sh
sudo apt install --no-install-recommends git cmake ninja-build gperf   ccache dfu-util device-tree-compiler wget   python3-dev python3-pip python3-setuptools python3-tk python3-wheel xz-utils file   make gcc gcc-multilib g++-multilib libsdl2-dev
        
pip3 install west
          
west init -m https://github.com/nrfconnect/sdk-nrf /home/runner/work
cd /home/runner/work
west update
pip3 install -r zephyr/scripts/requirements-base.txt
                    
sudo apt install --no-install-recommends cmake ninja-build
          
#install toolchains
cd /usr/local/
# get minimal version, without toolchains
sudo wget https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v0.15.1/zephyr-sdk-0.15.1_linux-x86_64_minimal.tar.gz
sudo tar -xvf zephyr-sdk-0.15.1_linux-x86_64_minimal.tar.gz
          
# install only necessary toolchains
cd zephyr-sdk-0.15.1
sudo wget https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v0.15.1/toolchain_linux-x86_64_arm-zephyr-eabi.tar.gz
sudo tar -xvf toolchain_linux-x86_64_arm-zephyr-eabi.tar.gz
sudo wget https://github.com/zephyrproject-rtos/sdk-ng/releases/download/v0.15.1/toolchain_linux-x86_64_x86_64-zephyr-elf.tar.gz
sudo tar -xvf toolchain_linux-x86_64_x86_64-zephyr-elf.tar.gz

export ZEPHYR_TOOLCHAIN_VARIANT=zephyr
export ZEPHYR_SDK_INSTALL_DIR=/opt/toolchains/zephyr-sdk-0.15.1/

Build and flash hello world app

  • edit …samples/helloworld/prj.conf
    • add line with “CONFIG_BOOTLOADER_MCUBOOT=y” //so that correct hex file is build
  • VScode
    • create build configuration
      • set board to thingy91_nrf9160_ns (so no secure version!). By doing this CONFIG_BOOTLOADER_MCUBOOT is set to ‘y’ (via thingy91_nrf9160_ns_defconfig), so we do not have to do this in our prj.conf file. Without this CONFIG_BOOTLOADER_MCUBOOT setting the necessary hex file app_signed.hex is not built;
    • build the application 
          pip install cbor2
    west build --pristine -b thingy91_nrf9160_ns
    • close the serial connection in vscode, or close vscode (otherwise you can not program hex file to Thingy, because the com port is in use)
  • put thing91 in mode for programming nrf9160 (switch Thingy91 off; hold big middle button and switch it on again)
  • Open NCS->programmer app via nRF Connect for Desktop
    • select device
    • enable MCUboot
    • clear files
    • add file; browse to ...samples/helloworld/build/zephyr/app_signed.hex
    • write file to thingy
  • Thingy: switch off and on via switch (plugging in/out USB cable is not enough, because Thingy91 is also battery powered)
  • start VScode (I used VScode to connect to the COM port; I could not get this working via Putty on Windows yet)
    • nrf terminal; connect to COM6 (windows), 115200 8n2 rtscts:off
  • In linux the following also works: screen /dev/ttyACM0 115200
Written on May 1, 2022