Blinky — 4-LED runner on nRF + Zephyr

Small Zephyr RTOS project that cycles through four LEDs on Nordic nRF development boards. Built with nRF Connect SDK (Zephyr). Good starting point to check the toolchain and board support.

What it does

• Uses the GPIO API to drive 4 LEDs (led0–led3 from devicetree).
• Steps through them in order: LED0 → LED1 → LED2 → LED3 → repeat, with a 100 ms delay between steps.
• Runs on nRF54H20 DK and nRF54L15 DK (see boards/ for overlays).

Requirements

• nRF Connect SDK (or nRF Connect for VS Code with the SDK extension).
• A board with at least one LED; for the 4-LED sequence you need a board that exposes led0–led3 or adapt the overlays.

Build and flash

From the project root, with the nRF Connect SDK environment loaded (e.g. nrf connect terminal in VS Code, or source zephyr-env.sh in the SDK):

# nRF54H20 DK (default)
west build -b nrf54h20dk/nrf54h20/cpuapp

# nRF54L15 DK
west build -b nrf54l15dk/nrf54l15/cpuapp -- -DOVERLAY_FILE=boards/nrf54l15dk_nrf54l15_cpuapp_hpf_gpio.overlay

Then flash with west flash or from your IDE.

Project layout

blinky/
├── src/
│   └── main.c          # GPIO setup and LED loop
├── boards/              # Devicetree overlays per board
├── CMakeLists.txt
├── prj.conf             # GPIO enabled
└── README.md

README.rst is the original Zephyr sample doc; this README describes this repo.