ESP8266-WiFi-MOD is a very tiny board. It is built around Espressif’s Wi-Fi chipset ESP8266EX. Module ESP8266-WiFi-MOD comes preprogrammed with UART-WIFI bridge demo software. This give possibility to connect to Internet with simple AT commands from any microcontroller occupied with UART interface. Source code for this application and complete Expressif SDK for the ESP8266 is publicly available. Included in the SDK are sources making this module a solution for pretty much everything you would need to do with an Internet of Things (IoT) thing. ESP8266EX requires minimal external circuitry. Main components on Module ESP8266-WiFi-MOD are SoC ESP8266EX, Winbond W25Q40BVNIG SPI flash, quartz crystal and integrated PCB antenna.