This is a bit more complex than one would first think, as the Arduino Mega2560 is a 5V board, and the ESP8266 are 3.3V parts. Level shifters to the rescue!

When we first heard about it a few weeks ago, we knew the ESP8266 UART to WiFi module was a special beast. It was cheap, gave every microcontroller the ability to connect to a WiFi network, and ...