The ESP8266 is well known as an incredibly small ... To get up and running you really only need to create three distinct voltage levels and have timing control to about 1us.

Programming it externally with a Teensy ended up not being much of an obstacle, but it did mean he was stuck with only two GPIO pins ... 0 – 3.3 V signal for the ESP8266, he came up with ...

an ESP8266 is even cheaper. And when I say cheaper, I'm talking about picking up one of these microcontrollers for $5 or even less. It's an incredibly cost-efficient device, with the only downside ...