Today, we would like to focus on an IT branch that is currently enjoying great popularity and is forecast to continue to grow strongly in the coming years. We are talking about Smart Energy. In particular, we would like to take a closer look at an IoT module that allows us to control domestic devices via smartphone. The NodeMCU ESP8266MOD module contains WLAN functionality, various inputs and outputs, a relatively powerful CPU and enough memory for programs. In this WLAN ESP8266 test with ESP8266 tutorial on OCinside.de we will program the mentioned functions ourselves and also deal with some enhancements, such as ultrasonic sensor, PIR sensor, infrared receiver, relay card, GPS module and 320x240 display.