A microcontroller is a single-chip microcomputer designed for embedded applications. In the context of the Internet of Things (IoT), an embedded system with direct or gateway-mediated Internet connectivity forms the core of a physical thing. The physical thing is what we call an IoT device. Simply put, IoT devices can be industrial machines, computer hardware, consumer electronics, home appliances, vehicles, gadgets, appliances, sensors, actuators, and any piece of equipment with an embedded, Internet-connected computing system. An IoT implementation drives ubiquitous connectivity and information exchange between heterogeneous smart devices by extending the Internet Protocol (IP) communication beyond computer networking and mobile Internet services to billions of resource-constrained embedded systems. The spirit, when applied to the Internet of Things, is aimed to transform the way people interact with their environment through human-machine collaboration in cyber-physical systems such as smart cities, smart buildings, smart homes, smart factories, intelligent transportation systems, smart farms, and smart grids.