Spektrální analyzátor zvuku s vizualizací

Abstract

This bachelor’s thesis deals with the design and implementation of a fourteen-band spectrum analyzer with graphical visualization on a matrix of 280 LEDs. The aim is to interactively demonstrate the frequency composition of an audio signal to potential students interested in the study of electronics.

The thesis describes the complete process, from the theoretical analysis of spectral band processing, through market research and the design of a custom printed circuit board created in KiCad software, to the actual assembly, commissioning, and testing of the device.

The core of the selected solution is an Arduino microcontroller. It processes data obtained from two MSGEQ7 integrated circuits, whose internal oscillator timing was modified in order to achieve the required number of frequency bands.

Part of the solution is the development of software for controlling a matrix of fourteen LED bargraphs, each consisting of 20 addressable RGB light-emitting diodes. In addition, the software also enables an extra text-scrolling mode.

In the final part, practical testing of the frequency response and measurements of the current consumption were carried out in both operating modes, as well as during operation of the control circuit with all LEDs turned off.