If we set GPIO0 low, however, the boot ROM inside the ESP8266 takes over and it begins communicating over the UART. Using this ... is a lot like programming an Arduino. static void ICACHE_FLASH ...

A lot of people have used ESP8266 to add inexpensive WiFi connectivity to their projects, but [Oscar] decided to take it one step further and program an Arduino over WiFi with the ESP8266.

The need for a second UART port ( and one that is not shared with USB) on the Arduino Uno is so great that the “SoftwareSerial” library in included in the Arduino IDE. It emulates additional ...