OptoShield: A Low-Cost Tool for Control and Mechatronics Education

Commercial educational tools for teaching feedback concepts in control systems engineering and mechatronics are generally expensive, large, complex and sensitive instruments; therefore cannot be used for homework assignments outside the classroom. This paper presents a novel open-source teaching aid that can be readily manufactured under AC3 and as such, is financially accessible to students and universities operating on a tight budget. The device proposed in this paper implements a simple optical experiment, allowing students to follow a prescribed brightness level using feedback control concepts. In addition to real-time control, the apparatus is also suitable for teaching signal processing and system identification principles. The educational aid presented here is attached to the popular Arduino microcontroller prototyping platform in a form of a miniature extension shield, thereby using a standardized physical layout and software ecosystem. We describe the hardware, the application programming interface (API) and library written in C/C++ for the Arduino integrated development environment (IDE) and the accompanying Simulink toolbox; moreover present sample exercises for system identification and proportional-integral-derivative (PID) control.