Audio oscilloscope using Galactic Unicorn with SparkFun Sound Detector

I’ve added a new module to the code mentioned in Guitar (instrument) tuner using Galactic Unicorn . The Galactic Unicorn can now draw a low-resolution oscilloscope trace of the audio signal from the electret microphone with positive triggering and a frequency counter between ~30 - 500 Hz.

A slightly older version of the code