For some mood lighting in the living room I mounted a lot of rgb leds in the cabinet. Rgb leds will be driven with 3 pwm channels on a Atmel mega-128. Controlling will be taken care of by the Joshua Bus .

Testing the leds:


For a nice fading it’s necessary that the fading will work like figure 2. In figure 1 all colors are increased every step with the same value, the disadvantage of this is that blue is finished first, software is easy to make. In figure 2 all colors are finished the same time, the step size for all colors is different. I wrote a routine that will take care of this.

Nice fading example:


Update: Replaced the ledstrips. The old strips had 3 leds for the colors, separated Red, green and blue led. This was not mixing very well and because the strips are close to the wall you could see the individual colors on the wall.
Placed now new strips with RGB led’s in 1 package.