An experiment with the LED sensor of an Arduino, linked to Processing graphics:
pulsating cat’s eye
When the light is high, the pupil of the cat’s eye widens, when the light is low, the pupil of the cat’s eye closes.
[I know in reality, the cat's eye works the other way round… ;) ]
--> The color of the pupil also changes, from bright (high value) to dark (low value)
the relevant part of the processing code:
if (data != null) { int intData = int(data); // ---> !! variable for incoming data
background(255, 255, 0); noStroke (); ellipse (560, 360, 600, 600); /* ---> 1. circle: 'background circle' (just as a referrence for the 2. circle) */
noStroke (); fill (intData, intData, intData); // set fill colour with the value read ellipse (560, 360, intData, 600); /* ---> 2. circle: the 'pupil' (visualizes the incoming data) */ }