This book provides a great way to learn about the use of Wi-Fi enabled microcontrollers by demonstrating several Internet-Of-Things applications of the ESP32 devices on small model railroads. The ESP32 is a powerful WIFI/Bluetooth-enabled System on Chip device that lets the programmer do a lot of cool things. The authors show ways to connect them to sensors, turnouts and transfer information to computers by using Wi-Fi technology. The first sections of the book provide a lot of guidance and demonstrate various capabilities to utilize the ESP32 along with the Mosquitto MQTT Broker. The final section of the book uses techniques from the earlier chapters to complete several applications on model railroad layouts of for example capturing data using infrared sensors to determine if sidings are occupied, determine the speed of trains on a layout, and a Wi-Fi DC throttle. This book is intermediate level based on the complexity of IOT systems but it is set up in way to aid a novice in gaining experience to complete the advanced applications and expand to the readers own model railroad projects.