OK so there is this new(ish) chip the ESP8266EX that promises a full wifi stack and a mcu all for £2-3. But the chip on it’s own isn’t so useful – so most of the excitement has been around the various modules made with the chip, some memory and an antenna or connector for one. Unfortunately there is a lot of diversity, modules being revised and so on – which makes choosing one of these modules quite difficult. Here I’ve tried to bring together all the info I could about these different modules to help you choose which one fits your needs best. If you have any information about these modules then please leave a comment and I’ll incorporate it! The modules have attracted the codes ESP-01 through ESP-12 – this document in Chinese and this webshop catalog formed the starting point. The ESP8266.com community and Squonk, shekel, TuxFanGKR and others deserve credit for gathering most of this infomation here.
The basic attributes of these modules are as follows:
Tinhead of the esp8266.com community contributed info about an older variant using the ESP8266 rather than ESP8266EX (may also be referred to as v080):
TuxFanGKR of the esp8266.com community reported that a pinout variant had made him let the magic smoke out! And a third variant (confusingly named ESP-02 version 2) has been spotted here. Pinout is of TuxFanGKR’s variant – photo of ‘version 2’.
A fifth pin has been added to the ESP-05 module carrying reset, thanks to esp8266.com contributors gbit and Didier9 for this info:
A variant of the ESP-07 has been reported with 2 extra connections (one of them ADC) by mvdlande on the esp8266.com forum:
Any corrections, omissions or improvements? Please leave a comment!
Thanks to comment below, pinout of module ESP-11 has been corrected.