Didactic Hardware in the Loop Platform: A Low-Cost Open-Source Approach

In evaluating and validating a physical system, real-time Hardware in the Loop (HIL) emulation offers advantages such as time and cost reduction, fault prevention, and the ability to conduct validations in an environment similar to its final application. On the other hand, low-cost technologies such as microcontrollers, digital signal processors, and FPGAs have been employed to leverage the advantages of HIL emulation in the teaching process. This article describes the implementation of a low-cost, open-access HIL didactic platform for use in subjects such as differential equations, systems dynamics, and control systems, among others. The platform is based on a Raspberry Pi Pico development board and features a graphical user interface (GUI). In the GUI, the user can visualize graphs of the emulated systems variables and real-time animation of its state and export the acquired data to a comma-separated file. The functionalities offered by the platform make it an affordable tool that allows users to evaluate the response of a dynamic system, whether it is open-loop or closed-loop, without the need for classrooms or specialized equipment. Unlike similar works where HIL techniques with low-cost hardware are employed for educational purposes, the proposal in this work is more cost-effective and integrates the described GUI. All the files necessary for implementing the didactic platform are openly available in a public repository, including those needed for PCB manufacturing.