This paper review explores the dynamic intersection of microcontroller architectures and Internet of Things (IoT) technologies, offering a comprehensive examination of shortlisted recent papers spanning diverse domains. Beginning with a discussion on a novel smart microcontroller architecture for IoT, the review delves into topics such as endpoint device interconnection, integrating microcontrollers into IoT, and the development of microcontroller-based learning media for IoT lab work. The exploration extends to the role of Field Programmable Gate Arrays (FPGAs) in IoT applications, comparing synchronous-logic and asynchronous logic 8051 microcontroller cores. The narrative broadens to encompass the vital role of microcontrollers in smart cities, emphasizing their potential applications across various domains. Lastly, the review addresses optimizations, computing paradigms, and future directions in microcontrollers for IoT, concluding with the design and affordability of an IoT Training Kit for practical industrial automation work. Through a synthesis of these papers, the review provides insights into the current state, challenges, and promising directions in the ever-evolving landscape of microcontrollers and IoT.