This document introduces Arduino, an open-source electronics prototyping platform. It discusses that Arduino is intended for artists, designers, hobbyists to create interactive objects. It then describes the Arduino hardware, including the microcontroller, I/O pins, and official and third party boards. It also covers the Arduino programming environment and language, and provides examples of common tasks like reading buttons and displaying to serial. Finally, it discusses common sensors, motors, and modules used with Arduino and points to the active Arduino community for support.