Random LED Dots
Channel: ednisley
Date: 20/05/2015

A simple multiplexed RGB LED array controlled with hardware SPI from an Arduino Pro Mini. Each pulse from a Geiger sensor produces a 32-bit random number that sets the color of one RGB LED site.

The first part of the video shows the "lamp test" sequence. Before the Arduino sketch begins running the LEDs show a static pattern, then the sketch blinks each LED site in succession, fills the entire array with random colors, and begins executing the main loop that changes one LED at a time.

The rapid count comes from a radium-illuminated wristwatch near the Geiger sensor that produces about 160 count/minute. The last minute shows the 12 count/minute background rate.

More info on my blog, starting at:
http://softsolder.com/2015/05/18/random-led-dots-hardware-layout/