Universal Remote Schematic

I'm making a universal remote for my senior design project. I was wondering if anyone has a schematic for any universal remote that's out now. I've tried to find one but all I find is other people who have asked this only to be told something like, "That's the easy part the hard part is constructing it," or "You should just buy one, it'll be better than a home-made one." If anyone could help I'd be very appreciative.

 

You might have a look here:
http://www.tauntek.com/irmimic-learning-ir-remote-control-transmitter.htm
Basically, just a programmable microcontroller that can mimic the functions of other IR remotes.