What on earth would you expect BTN to refer to? The ESP8266 module doesn't have a button on it!
Is that a polite way of calling me a D.A. ? I'm staring at my ESP8266 board with two buttons on it, and yes, I'm under the legal limit right now . . . .
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
What on earth would you expect BTN to refer to? The ESP8266 module doesn't have a button on it!