Devised when learning to use a pitch-detecting arpeggiator pedal (EQD). This quirky project got me back into circuit making and started Red Barn.

I needed a constant-volume pitch generator that did not decay like a plucked string on an instrument.
Remembering some simple 555 timer circuits from university, created a simple circuit that can jump between two pitches, with interesting ways to select the pitch of the second note.

The tone generated is a square wave, but the tone rolls off some highs to smooth it out a bit.

Controls:
-On/Off & Volume
-Tone
-Primary Pitch
-Secondary Pitch
-Mute (temporary pushbutton)
-Pitch Jump (temporary pushbutton)
-Pitch Trigger: selects between
i) secondary pitch knob, or
ii) light activated sensor (also turns on gooseneck LED))