The ESP8266 is a module that adds a WiFi connection to your Arduino projects and more. This module is a true Arduino Killer. It has several GPIO. The most used models are the ESP-01, which has 2 GPIO (but not EC which is a shame) and ESP-12E model which features 12 GPIO (CE compliant). The ESP8266 can be programmed in Lua (language similar to Python) or using the Arduino IDE classic. For less than 2 euros you have a microcontroller with 2 GPIO with which you can make a small connected object (eg a connected button) without the need for an Arduino. In this category you will find everything you need to get started with the ESP8266: how to program in Lua or using the Arduino IDE, how to reinstall the original firmware, how to flash a custom firmware, the examples of assembly and codes …