This article presents a developed system built on the STM32 Smart V2.0 board based on the STM32F103C8T6 microcontroller. The created system allows the calculation of estimates of the excess kurtosis of signals, including audio signals, which is currently used in a wide range of tasks. Since existing implementations of systems for calculation of the excess kurtosis are too expensive, large in size, or designed to perform other more resource-intensive tasks, the creation of a compact and affordable system remained a challenge. The system proposed in this article, with the exception of the computer, consists of affordable components of small size, and also has the ability to exchange information via the USB interface, which allows for the processing of digital signals sent from other devices. The article outlines the problems and limitations of the system, conducts a study of its performance, and also determines the errors in calculating estimates of the excess kurtosis. Calculations performed using the microcontroller were verified using the MATLAB® application software package.