The RGB LED contains three LEDs encased in one shell: Red, Green and Blue (some contain an extra blue led – as blue LEDs generate less output intensity (candela) per mA). It looks like a single white led except that it has four leads – one for the common ground connection and one for each led.
The average current through each of the LEDs determines it’s light output i.e. its contribution to the total output color. So by controlling the average current through each LED you can create almost any other color.
How to drive an rgb led using three microcontroller pins - [Link]
This is a ScreenKey – a programmable button that can display any graphic with a backlight that is itself configurable to be a handful of different colors. We have both RGB and RG versions. So cool !
ScreenKey - [Link]
Jörg Wolfram used Atmega32 has been developing interesting project so called AVR-ChipBASIC. Simply speaking this is a basic language programmable chip computer which his capable to run basic programs and with ability to display results in RGB TV screen.
AVR-BASIC-Computer - [Link]
todbot blog writes:
LEDs should be smarter. Sure we have flashing LED assemblies and even rudimentary RGB-flashing discrete LEDs. But LEDs themselves are predominately just dumb lights. There’s no real reason for this. Fab processes for microcontrollers and LEDs aren’t that dissimilar. It should be possible to have both in a single LED-like package.
There is a glimmer of this happening, like the “RGB LED Slow Colour Change” LEDs you can get. You can see an example of these being used on the Embarrasingly Easy CaseMod. Unfortunately you can’t change the cycle time or anything else of how these LEDs work. So let’s make our own. These prototype Smart LEDs will necessarily be larger than a production run, but the size is getting close, giving us a feeling for how we might use them.
Smart LED Prototypes - [Link]