The BBC Micro:Bit microcontroller is an affordable microcontroller specifically designed for S.T.E.M. topics and Educational Robotics applications. Due to its technical specifications, small size, and built-in sensors, it is an attractive solution for use in the educational process at any level of education. This book is a comprehensive guide to the BBC Micro:Bit microcontroller, presenting how to connect and program it using Blocks code, JavaScript, and (Micro) Python. The book starts with simple applications and educational scenarios for beginners, gradually increasing the difficulty level of the applications, resulting in more complex applications such as remote control and message display with external screens. All applications are presented step by step without requiring the reader to have knowledge of electrical circuits and programming. In each thematic unit, all the necessary information needed for the development of the applications is provided, as well as detailed diagrams and images that the reader can follow in order to successfully complete each activity.