With the complete and self-contained Wi-Fi networking capabilities, ESP8266EX can perform either as a standalone application or as the slave to a host MCU
About This Guide This document introduces the specifications of ESP8266EX, including the following topics. Chapter Title Subject Provides overview introduction to ESP82 serials, including features, Chapter 1 Overview protocols, technical parameters and applications. Chapter 2 Pin Definitions Provides introduction to pin layout and the relevant description. Describes major functional modules and protocols applied on Chapter 3 Functional Description ESP8266EX including CPU, flash and memory, clock, radio, Wi-Fi, and low-power management. Provides descriptions of peripheral interfaces integrated on Chapter 4 Peripheral Interface ESP8266EX. Chapter 5 Electrical Specifications Lists the electrical data of ESP8266EX. Chapter 6 Package Information Illustrates the package details for ESP8266EX. Provides detailed pin information including digital die pin list, buffer Appendix Pin List sheet, register list, and strapping pin list. Release Notes Date Version Release Notes 2015.12 V4.6 Chapter 3 updated. 2016.02 V4.7 Section 3.6 updated. 2016.03 V4.8 Section 4.1 updated. 2016.04 V4.9 Chapter 1 updated.