- Arduino Pro Nano
- 3x 220ohm resistors
- 1x 4.7kohm resistor
- 1x 1n4001 diode
- 1x 3v LED (I used red)
- 1x momentary, normally-open pushbutton switch
- 1x 3.5mm TRS audio jack
- 1x 5.5mm (2.1mm inner) power barrel jack
- 1x Hammond 1590A enclosure
Wire the barrel jack with a negative center, in order to use a standard guitar pedal power source. It is also possible to forego the 4.7kohm resistor in favor of using an onboard pull-up resistor for the pushbutton switch.
See the GitHub link for the Arduino sketch.