The photosensor is a simple cadmium sulfide cell, which measures the intensity of light bouncing back from an object as an Arduino drives the LED through all possible colors with PWM signals.

Those Cadmium Sulfide lights sensors usually have a very wide swing of resistance when exposed to varying levels of light sensitivity. That makes for great resolution when reading them using the ...

They also tested different types of buffer layers in the proposed cell configuration, in an effort to find non-toxic alternatives to cadmium sulfide (CdS). For the buffer layers, they considered ...