There are any number of projects for which it would be handy to animate LEDs from a PC. Not a microcontroller, but a full-on PC. Media — music and video — are a natural for PCs, and tools like Max/MSP and Processing are a natural for creating media-based software sketches. (We use “PC” here in the generic “personal computer” sense, not in opposition to Mac; Using a combination of Processing and Arduino, everything shown here runs as well on Mac or Linux as it does on a Windows system!)
As a first demonstration, we’ll build a simple “Ambilight ” clone. Ambilight is a feature of some Philips televisions that projects colored light onto the wall behind the display , synchronized with the content on the screen to create an immersive effect. The authentic Philips system is well-integrated into the TV and works from any video source. Our facsimile, being computer-driven, works specifically with media content from your PC. This means its perfect for watching Youtube, TV or Movies on your PC or playing games!
Adalight – Make your own DIY Arduino-powered ambient “Ambilight”-like lighting rig - [Link]