Implementing classical transforms for audio signal processing on ESP32

Santos Santander J.A.; Arguelles Bendezú I. · Proceedings of the LACCEI international Multi-conference for Engineering, Education and Technology (2025) · DOI: 10.18687/leird2025.1.1.912

Resumen

This study addresses the practical implementation of classical digital signal processing techniques, specifically the Fast Fourier Transform (FFT) and the Z-transform, on the ESP32 microcontroller, an inexpensive and versatile platform programmed using the Arduino IDE. Spectral analysis and audio filtering examples were developed, applying the FFT to identify frequency components and suppress unwanted ranges through spectral editing, and using the Z-transform to design a band-stop FIR filter. Experimental validation was carried out with a PCM5102A DAC, with the outputs observed on an oscilloscope, which demonstrated real-time signal reconstruction and manipulation. The results showed that the FIR filter based on the Z-transform exhibited lower latency and greater temporal continuity compared to the FFT method, making it more suitable for embedded applications. Overall, this work constitutes an accessible educational resource that bridges mathematical theory and experimental practice, fostering learning and innovation in digital audio processing on low-cost platforms. © LEIRD 2025.All rights reserved.

Instituciones: Universidad Tecnológica del Perú