In the field of engineering and exact sciences, there is a constant demand for experimental verification of control strategies, and modulation schemes, among other aspects. For this reason, undergraduate laboratory classes should have modern approaches to control systems education using simulations and experiments to facilitate the learning process. This paper presents the development of a low-cost hardware-in-the-loop platform for linear system emulation. The platform is an AD-DA system that simulates mathematical models in discrete time. The project consists of software and hardware elements that allow the user to send to the microcontroller the parameters by a PC application. The app sends the sampling frequency and the transfer function to the STM32F103 microcontroller board that runs the difference equations in real time. Experimental results done with first and second-order systems, varying the sampling frequency demonstrated the quality of the didactic platform in control system laboratory classes. https://doi.org/10.53316/sepoc2022.028