For our final project, we have chosen to create a stoplight using the ATxmega256A3BU microcontroller. This project idea is based off of a similar project done by a team member in Arduino. The circuit includes two stoplights (with a red, yellow, and green LED each), as well as two sets of lights for a crosswalk. The user can initiate the crosswalk sequence by clicking a small button within the circuit. This will interrupt the stoplight cycle and, theoretically, give a pedestrian a walk sign. We found this to be an interesting, and challenging project; however, it is very practical.
Below is a link to a YouTube video showing a complete cycle of the stoplight circuit.