This book provides a platform to get started with Internet of Things (IoT) with 8051 including programming basics and interfacing of the devices in designed systems. It presents a unique combination of 8051 with ESP8266 and I/O devices for IoT applications supported by case studies to provide the solutions to real time problems. The programs and circuits are tested on real hardware and explore different areas in IoT applications. Divided into four sections, it explains the customized boards for IoT applications followed by interfacing of 8051 and ESP8266 with I/O devices. It describes basic to advanced interfacing with special devices, server design and data logger with different platforms. Aimed at senior undergraduate and graduate students in electrical and electronics engineering, it: Covers 8051 and ESP8266 programming and interfacing of I/O devices with 8051 and ESP8266 Includes application with the real time examples to understand the basic concept with interfacing complexity Provides hands-on practice with 8051 and ESP8266 for IoT applications Discusses case studies and programming tested on real hardware during handling the industrial and student projects Reviews smart devices integration with IoT