This keyboard is based on ZMK and the Adafruit nRF2 bootloader

This firmware works with the custom board defined at Key-B hardware. And this repository works with the ZMK github-action template. So it compiles on the cloud on a github-actions workflow.

The highlighted files are the modified ones, the rest are the same as the template.

.github/
└── workflows/
    └── build.yml  
boards/
├── shields
└── arm/
    └── `keyb/`
        ├── `Kconfig`
        ├── `Kconfig.board`
        ├── `Kconfig.defconfig`
        ├── `board.cmake`
        ├── `keyb.dts`
        ├── `keyb.yaml`
        ├── `keyb.zmk.yml`
        ├── `keyb_defconfig`
        └── zmk.code-workspace
config/
├── `keyb.keymap` (keymap file)
└── west.yml
zephyr/
└── module.yml
`build.yaml`

• keyb/: Kconfig and DTS files defining the custom board, modified from the nice!nano board definition
• keyb.keymap: Keymap file for the keyboard.
• build.yaml: Edited to build the keyb board.

We are not using a shield with a standard board, so we leave the shields folder empty.

Pushing code to this repository will trigger a github-actions workflow that will compile ZMK with the configuratin defined in the repo. You can find the resulting UF2 binary here, in the corresponding workflow tab.

Official instructions, here: Adafruit nRF2 bootloader

• BootLoader Mode:
  • Double click reset button
  • ESC + Reset

I have a fork of the original Adafruit Bootloader here. It is already configured with the information of the Key-B board.

it also has a fix for working with gcc version 13

Clone, and Init the repo

git clone https://github.com/SaidAlvarado/Adafruit_nRF52_Bootloader
cd Adafruit_nRF52_Bootloader
git submodule update --init
git fetch --tags

Build the Key-B board

make BOARD=key_b all

Once the project is built you can find a uf2 binary in:

Adafruit_nRF52_Bootloader/_build/build-key_b/update-key_b_bootloader-0.8.3_nosd.uf2

This can be thrown in the UF2 upgrade folder like any other firmware and it should work.