Sky Color Monitor

I hooked the stamp up to an always on Linux machine that was my gateway router at the time. I programmed it to observe sky color with the intention of setting my laptop background color to match my home sky while traveling.

I added three CdS photo cells to the stamp and cut little squares of photographic filters for each in red, green and blue.

I tweaked the sensor readings so that it came out blue on a blue sky day. It mostly came out pale blue of some brightness any time I sampled.

I recorded brightness day and night. After months I could see the days getting shorter. Sweet.

I started sampling Webcam Sky Survey around the world on an hourly basis. I saved 16 pixel squares captured from the sky and assembled them into mosaics that showed the same sinusoid day length variation as my stamp.

The color never seemed to work, probably because I was really looking at trees and they didn't reflect the sky color particularly well. What was I thinking?

The stamp was too heavy to stay in place on the window year after year. I eventually replaced it with a single CdS cell hooked to an analog input on my Sensor Server Teensy.