ESP8266 IoT Embedded Modules Olimex ESP8266 Internet of Things (IoT) Embedded Modules are based on the ESP8266EX chip, a highly integrated SoC that includes a Tensilica L106 32-bit core processor. The L106 processor also includes SRAM, a power management unit, and an RF fron- end. The ESP8266EX features a number of interfaces such as I2C, SPI, SDIO, and free GPIO pins. The chip allows the implementation of a Wi-Fi® TCP-IP stack with only a few extra components.