There are a number of different modules that all feature the ESP8266EX chip - some that have been numbered ESP-01 to ESP-12 as well as others, and new ones are being made all the time. ESP-01 module looks like this (ensure you have later version with chip marked ESP8266EX): And we'll be using a Raspberry Pi running Raspbian operating system to talk to the module. As well as these two boards you'll