embedded-departure-board

Development

Requirements

• Python 3
• Zephyr SDK

Setup

1. Clone and enter the repo
2. Create a Python virtual environment

   python3 -m venv ./.venv

3. Activate your Python virtual environment

   source .venv/bin/activate
   # Or, if you're a direnv user, leave and come back
   cd
   cd -

4. Install West

   pip install west

5. Run

   west update

6. Install Python dependencies

   pip install -r zephyr/scripts/requirements.txt
   pip install -r nrf/scripts/requirements.txt
   pip install -r bootloader/mcuboot/scripts/requirements.txt

Recomended

• Read the Zephyr Getting Started Guide to install the required development tools (system packages, Zephyr SDK, and udev rules).

• To save on space, you may want to intall a minimal bundle Zephyr SDK release and the arm-zephyr-eabi toolchain. The full release includes all avaiable toolchains.

• Read the Introduction to the nRF9160 Feather to better understand the dev board we are using.

• If you plan making changes to the LTE modem configuration you should understand the various modes: Maximizing battery lifetime in cellular IoT: An analysis of eDRX, PSM, and AS-RAI

Docker

Zephyr supplies various Docker images for development.

Our Github Actions build workflow uses the Base Image (ci-base).

Build

west build ./app -b circuitdojo_feather_nrf9160_ns

Programming

Flashing

Flashing the device with an external programmer is quicker than using a bootloader. More importantly, it's the easiest way (and currently the only tested way) to secure the bootloader, update the modem firmware, and use the cortex-debugger.

Requirements

• External programming device, the nRF5340 Dk is what we currently use.
• 6-pin Tag Connect cable
• J-Link software.
• nRF Command Line Tools.

Run

west flash -r nrfjprog --erase --softreset

Uploading via the bootloader

Currently we are not using a bootloader, but it will be required for OTA firmware updates. It's also the only way to flash the device without an external programming device.

Requirements

• Newtmgr
• Ensure CONFIG_BOOTLOADER_MCUBOOT=y is set in app/prj.conf

Setup

1. Create a "serial" profile in newtmgr:

newtmgr conn add serial type=serial connstring="dev=/dev/ttyUSB0,baud=1000000"

2. Put the device into bootloader mode.

Run

newtmgr -c serial image upload ./build/zephyr/app_update.bin

VSCode

This repo includes .vscode/tasks.json to make develpoment easier. The included tasks are:

• Build
• Load image via bootloader
  • Expects a connection profile named "serial" in newtmgr
• Serial Monitor
  • Uses pyserial-miniterm, which should already be installed in your venv
  • Assumes the device is connected at /dev/ttyUSB0
• West Flash
• West Flash and Monitor
• Build AT Client
  • Builds the At Client sample provided by nrf.
  • Useful for debugging via AT commands. Use the "LTE Link Monitor" app from nRF Connect for Desktop to send AT commands

Creating a Release

Update the VERSION file. On a successful push to the main branch the release workflow will; create a new release, generate release notes, and upload the freshly built hex/bin files to the release.