Vizualizacija zvočnega signala z matričnim LED prikazovalnikom

KOROŠEC, JAKA (author), Pirc, Matija (mentor)

V tem diplomskem delu sta predstavljena izdelava in delovanje matričnega LED prikazovalnika, ki prikazuje frekvenčni spekter avdio signala. Matrični LED prikazovalnik je sestavljen iz gibljivih LED trakov SM16703, krmiljen pa s pomočjo mikrokrmilnika STM32G431KBT6. Poleg metode razvoja, je natančneje predstavljen in osmišljen vsak posamezni sestavni del projekta ter njegova vloga v celotnem sistemu. Podrobno razložim način nadzorovanja LED traku in predstavim rezultate meritev s katerimi sem preverjal zahtevano časovno točnost za krmiljenje LED traku ter odstopanje ugotovitev od zahtev specificiranih v podatkovnem listu. Utemeljim tudi izbrano metodo za zajemanje vzorcev avdio signala ter način obdelave tega signala pred zajemanjem. V grobem je opisan tudi način generiranja kontrolnega signala za LED trak. Preveril sem učinkovitost posameznih metod za pridobitev frekvenčne vsebine avdio signala. Predstavljene so tri različne metode; strogo matematična, uporaba splošnih knjižic za programski jezik C ter uporaba knjižic prilagojenih za ARM mikrokrmilnike. Opisana je tudi izvedba programa, kjer sem za vsak del programa izmeril koliko časa mikrokrmilnik zanj porabi ob uporabi najučinkovitejše metode. Rezultat tega projekta je vizualni modul, ki prikazuje frekvenčno vsebino avdio signala. Raziskal sem najučinkovitejše metode za razvoj takega projekta na sistemu Nucleo-G431KB.

• Language: Slovenian
• Keywords: matrični LED prikazovalnik, mikrokrmilnik, avdio signal, Fourierjeva transformacija, frekvenčni spekter
• Work type: Bachelor thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2020
• PID: 20.500.12556/RUL-119817
• Publication date in RUL: 11.09.2020

Secondary language

• Language: English
• Title: Audio Signal Visualization Using an LED Matrix Display

Abstract

In this thesis I present the development and funcionality of a matrix LED display, which displays the frequency spectrum of an audio signal. The matrix LED display is built from flexible LED strips. The driver for the LED strips is an STM32G431KBT6 microcontroller. Apart from the development method, I present each component of the project and its role in the whole system. I explain the controlling of the LED strip in detail and present the results of the measurment I made to test the required timing accuracy required to drive the LED strips, as well as the deviation of the findings from timing requierments specified in the data sheet. I also argue the chosen method for sampling and processing the audio signal. Generation of the LED strip control signal is also briefly discussed. I tested the efficiency of specific methods used to extract the frequency content of the audio signal. I present three methods; the strictly mathematical one, the use of general libraries for the C programming language and the use of libraries specialized for the ARM microcontrollers. The final program is also described, where I also measured the time each part of the program takes to execute while using the most efficient method. The result of this project is a visual module, which shows the frequency content of an audio signal. I researched the most efficient methods for the development of a project like this on the Nucleo-G431KB development system.

• Keywords: matrix LED display, microcontroller, audio signal, Fourier transform, frequency spectrum