Lots of people like playing Minecraft. It has something in it that keeps those blocks stacking. In Minecraft you can affect virtual world by building it with blocks. But what about real world? This is what Charles Lohr thought about. He thought it would be fun to transfer action from Minecraft world in to physical world and so avrcraft project was born.
He made an AVR server using Atmega328 and ENC424J600. Using server multiple players may connect to it and do regular stuff, build blocks, control AVR I/O pins and chat. As seen on video demo, DDR, PORT pin bits can be switched using built toggle switches and these changes are immediately seen on real physical board. Now it is up to imagination what fun things to do next.
Embedds highly recommends EasyEDA for circuit and PCB design