“The success of the ESP8266 from Espressif Systems is undeniable. It is a powerful microcontroller with built-in Wi-Fi capabilities and is readily adaptable to a multitude of uses in the rapidly growing IoT (Internet of Things). One of the few difficulties to using the IC has been updating the firmware in the thousands and thousands of development modules that have permeated the market. Judging by the large number of comments posted, this article on All About Circuits has been a help to many. However, the passage of time has revealed some corrections and improvements needed in the information that was provided in October of 2015, and presenting that information is the goal of this article.”