Computer controlled RGB LEDs
I initially interfaced an Arduino UNO with two 3 watt RGB LEDs from dealextreme. MOSFETs were used to drive higher currents from the Arduino analog out (PWM) pins. Ordinary printer paper makes a surprisingly good diffuser for the LEDS. Light color is set via simple serial commands.
Following the initial Arduino prototype, I have implemented simple RGB light drivers using a low cost (~$1) PIC16F720 microcontroller. By adding a low cost ($5 to $10) bluetooth serial module, light colors can be controlled wirelessly, such as from an Android enabled phone. The lights are programmed to maintain the last color when no commands are received.
For one light, web access has been enabled through a simple Python interface. Using this interface, GET requests of a specific format are translated into light color changes. This approach should allow faster light changes than database polling, another alternative that was considered.
Future work for these lights includes implementing additional ambient lighting modes or an audio visualization mode.
© 2015 by Ian Bullock
Contact: ian.bullock @yale.edu