The Color Machine (La macchina dei colori, in Italian language) is a tool to teach children about the use and the operation of RGB color coding, which is used in all digital devices (TVs, smartphones, computers, etc.).
Using 3 knobs you can increase the percentages of red, green and blue separately, and the LED strip at the top of the machine lights up consistently with the color mix choosen. In this way approximately 16 million of colors can be generated. The Color Machine has 4 different operating modes: "let’s create colors", "guess the color", "the names of the colors" and "demo". Under the guidance of a teacher, children can play and learn at the same time to recreate colors with additive synthesis. This device is currently used in the educational workshops of Musil - Museum of Industry and Labour of Rodengo Saiano (Italy).
The device was built using an Arduino Mega 2560 as basic element. Each of the 3 knobs controls 1 incremental encoders, mounted on a LED ring breakout board (see Mayhew Labs rotary encoder LED ring). The output is made through a RGB backlight positive LCD display and a strip with 16 RGB LEDs (controlled through shift registers). Some custom-designed PCBs have been developed and printed to build the LED strip and to make wire connections easier. The electronics are housed in an aluminium box, suitably modified. A custom aluminium front panel was also designed and built.
More info here: http://www.ghidiniguerrini.it/projects/color_machine/
See it in action: - prototype: http://www.youtube.com/watch?v=mJklvJ9nMaU - final versione: http://www.youtube.com/watch?v=JmPkz6jBYJ0