The Crowtail-Nano Base Board v1.0 Shield plugs into nano Crowduino and is the foundation of the Crowtail system. ALL I/O ports of the Crowduino are exposed and adapted into Crowtail connectors which include digital I/O,analog I/O,and specialized ports(I2C https://elecena.pl/product/7560021/crowtail-base-board-for-arduino-nano-2-0 2017-02-01 https://elecena.pl/product/7560021/crowtail-base-board-for-arduino-nano-2-0 2025-12-17