Utilizing an individually built mobile robot in the laboratory of an advanced digital logic design course in conjunction with a final class competition

Abstract

This paper describes the development and implementation of a series of laboratory projects utilized in a junior level, required course for computer engineering majors titled, “Advanced Digital Logic Design.” Eleven of the 13 lab experiences are directly related to this project. The first five labs are mainly construction labs where students are developing practical, hands-on skills and gaining familiarity with common prototyping practices. These skills include (a) utilizing a 3-D printer in order to create the chassis, wheels, and sensor mounts, (b) disassembly, modification, and reassembly of two servo motors, and (c) assembly and soldering two custom-designed printed circuit boards (PCB)-totaling approximately 50 components and 200 solder points. Once all the subsystems are complete, they are screwed together, along with a battery pack and front contact sensing bumper. In the final six labs, the students systematically build-up the various digital designs needed in order to autonomously control their individually-built mobile robots. These labs include digital designs (a) to control the servos, (b) to play an accurate song on a small speaker, (c) to communicate with five infrared (IR) distance sensors in order to obtain range information, (d) to create a complex finite state machine (FSM), and (e) to navigate the robot through a set of obstacles. A 240 logic cell Complex Programmable Logic Device (CPLD) limits each student's design space and, consequently, efficiency of implementations is enforced. Milestones are graded throughout the semester in order to encourage proper progress toward the goal of participating in the final class competition; this event is where guests are invited and small prizes are awarded for the top three finishers. This style of project-based-learning provides students with opportunities to gain practical skills and, with these skills, to increase students' confidence in their abilities to design and solve real-world problems. Additionally, I have found student motivation and interest to be high, which leads to increased rates of learning and accomplishment. Since the cost of the components is kept low (approximately $35), all students retain their respective robots and can continue working with them beyond the completion of the course.