Turn Light Into Control.
A compact photoresistor-based controller that turns light into real-time expression control. (TRS)
The photoresistor is connected between the tip and ring of the jack, with its resistance varying from less than 1kΩ in bright light to over 1MΩ in darkness. A 47kΩ resistor connects the tip to ground and this resistor and the photoresistor simulate the behavior of a real expression pedal for use with all kinds of guitar effects.
Beware: Do not unscrew the 1/4" jack end, the photo resistor can be easily damaged.
