Simple traffic light controller: A digital systems design project

In the past few years, laboratory exercises for our Digital Systems course were typically self contained. The lack of integration prevented students from fully realizing a complete digital system during the course of the class. The simple traffic light controller design project was introduced to alleviate this shortcoming and to ensure students gain experience in solving implementation and interfacing problems of a modern digital system. Students implement a fully functional traffic signal controller for a four-way intersection. The intersection is complete with sensors to detect the presence of vehicles waiting at or approaching the intersection. The project incorporates many concepts and components that are discussed in detail throughout the course. These include FPGAs, VHDL for modeling and synthesis, finite state machines, embedded microprocessors, memory interfaces, serial communication, and signal synchronization. A bottom-up with a partially specified design methodology is used to encourage students to use their breadth of knowledge and creativity. By the end of the project, students will have gained a better understanding of digital system design methodologies through hands-on experience.