Tri-Color Animated LED Cube Lights Up the Night

Dan — Sat, 02 May 2009 03:17:39 +0000

Tri-color Animated LED Cube

This is a cool example of a simple project you can do with a microcontroller. (See Video Below)

Using bi-color LEDs, a little multiplexing, and a microcontroller, green, orange or yellow can be lit up individually at any of the 27 locations on the cube. Each of the bi-color LED’s physically contain two LEDs inside of them with a common cathode. If both sides of the LED are on, the LED appears to glow yellow, making a third color.

It works by refreshing each cathode level at a rate faster than the eye can perceive. Because light receptors in the eye continue to â€™seeâ€™ light for about 15ms after the light has gone away, this clever trick allows the use of microcontrollers to turn on power to each cathode level, one at a time, without any visible hint of the led losing power, so long as each cathode level is refreshed at approximately 60Hz.

The end result is a neat animation in up to three colors:

Tri-Color animated LED Cube

[Tri-Color Animated LED Cube]

Robotics Blog » multiplexing

Tri-Color Animated LED Cube Lights Up the Night