909 style drum machine for ESP8266. modification of Jan Ostman's code http://blog.dspsynth.eu/audio-hacking-on-the-esp8266/ this version uses trigger inputs instead of MIDI. trigger inputs should be buffered so you don't exceed 3.3v. I used NPN transistors - 100k to base, emitter grounded, collector to the port pin which has pullups enabled. also added an audio mute to avoid the glitching that happens every once in a while.
R Heslip May 2018