Lolren has published nrf54-arduino-core on GitHub, an Arduino core for Nordic’s nRF54L family that talks to the hardware at the register level. There is no Zephyr runtime underneath and no separate nRF Connect SDK install. Targets include the Seeed XIAO nRF54L15 and XIAO nRF54LM20A, HOLYIOT modules, generic modules and the Nordic nRF54L15 DK.

The usual Arduino calls work: pinMode, digitalWrite, analogRead, Wire, SPI and Serial.

Bluetooth LE is the main wireless surface, with a bundled Bluefruit52Lib compatibility layer so Adafruit-style sketches port over with small changes. ArduinoBLE is not the native BLE library here.

The core also exposes the VPR RISC-V coprocessor and handles board-specific sleep, including the nPM1300 PMIC and QSPI flash deep power-down on the LM20A.

It is installed through the Arduino IDE Boards Manager, or use PlatformIO, which has been supported since release 1.0.21 with GDB debugging and Unity tests.…