Turning a toy into a didactic industrial regulator

This manuscript presents a didactic application based on the LEGO^®MINDSTORMS^TMRCX^TMarchitecture¹, and the BrickOS operating system. The RCX is turned into a stand-alone regulator, that can accommodate for one or more PIDs in various configurations, and whose operator interface relies entirely on the LCD display and the buttons of the RCX. The so obtained regulator is suitable for several modulating control experiences, that anyone can make at home using only standard LEGO parts. In addition, extending its functionalities is a very interesting and didactically useful exercise, as the problems to tackle are quite similar to those encountered when dealing with real industrial devices.