I built this with an Arduino previously, but I am working on porting this over to an ATTiny45 ao I can put it on perfboard. Basically I have two PWM outputs, the first (A) moving from a 0-100% duty cycle based on the output of an adjustable-wavelenth sine wave, and the second (B) doing the same thing on a sinewave shifted 90° out of phase (aka cosine) such that when A is at 100%, B is at 0%, A and B are wired to the blue and green channels of the RGB LEDs such that A drives the blue channel of the first and third LEDs and the green channel of the middle LED.
Smaller version of the popular ATMega AVR line used in the Arduino Uno.
Large, diffused RGB LEDs
Only two color channels used.
Appropriate Resistors for LEDs
One for each channel but you coulkd wire the resistors on the ground side in parallel.
5V Power Source for AVR
Wall pack, 6V in AA batteries, voltage regulator circuit
Digging this old project up becuase its time to put it on a perfboard, It was originally written for the Arduino Uno, so I need to port the .ino code in AVRC and manually take care of setting the Timer/PWM registers. Then I need tomeasure the power consumption and see if I can drop the clock speed any. Finally, I need to add a LDO regulator and set it up on perfboard with a 9V battery.