Internet of Things with 8051 and ESP8266 provides a platform to get started with the Internet of Things (IoT) with 8051. This book describes programming basics and how devices interface within designed systems. It presents a unique combination of 8051 with ESP8266 and IO devices for IoT applications supported by case studies to provide the solutions to real-time problems. The programs and circuits have been 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 the means by which 8051 and ESP8266 interface with IO devices. It spans levels from basic to advanced interfacing with special devices, server design, and data logging with different platforms.