Cyber-physical systems are a genre of networked real-time systems that monitor and control the physical world. Examples include unmanned aerial vehicles and industrial robotics. The experts who develop these complex systems are retiring much faster than universities are graduating engineering majors. As a result, it is important for undergraduates to gain exposure to these kinds of complex systems. This paper describes UPBOT, a robotics testbed hosted at the University of Portland, Portland, OR. The testbed features an extensible robot built from an iRobot Create chassis and a computationally powerful embedded system equipped with a wireless card. In the Spring 2012 semester, the testbed was used for a course project designed and assessed in the style of contract learning. Overall, students were enthusiastic about the hands-on and self-paced nature of the course, but some were concerned by the level of freedom. The lessons learned may inform other educators in project design in robotics education.