A couple of weeks ago I got a bunch of Olimex ESP8266 development boards (MOD-WIFI-ESP8266-DEV) for IoT prototyping. ESP8266 itself is a neat little WIFI-enabled SOC by Espressif. It has 16 GPIO pins, support for I2C, SPI, UART etc. and even an ADC. Unfortunately, it also lacks good documentation. Flashing the ESP8266 is done over UART but as there are plenty of ESP8266 modules and USB-to-UART devices available, it’s not always easy to find instructions. I have the SparkFun FT231X Breakout which is nice general purpose USB-to-UART device thanks to its full set of pins. As I couldn’t find a tutorial for it, I had to go through some trial and error to get everything working. This is a brief tutorial of what kind of setup I currently have for programming Olimex ESP8266 development boards.