ESP32 Audio Project: Signal Generator & Audio Processing

In this project, we’ve developed an advanced audio system based on the ESP32 microcontroller. The system combines signal generation with audio processing functions for professional applications.

Project Overview

The ESP32 audio project includes:

• Signal GeneratorGeneration of various waveforms (sine, square, triangle)
• Audio ProcessingReal-time audio processing and filtering
• Wi-Fi connectivityRemote control via web interface
• LCD displayLocal display of parameters and status

Technical specifications

Hardware

• ESP32 DevKit V1
• I2S Audio Codec (MAX98357A)
• .8″ TFT LCD display
• Rotary encoder for control
• External amplifier circuit

software

• Arduino IDE / PlatformIO
• ESP-IDF framework
• FreeRTOS for multitasking
• Web server for remote control

Implementation

Signal generation

void generateSineWave(float frequency, float amplitude) {
    for (int i = 0; i < BUFFER_SIZE; i++) {
        float sample = amplitude * sin(2 * PI * frequency * i / SAMPLE_RATE);
        audioBuffer[i] = (int16_t)(sample * 32767);
    }
}

Audio processing pipeline

1. Input CaptureMicrophone input via I2S
2. Digital FilteringHigh-pass/Low-pass filter
3. Effects ProcessingReverb, echo, compression
4. OutputI2S audio output

Application areas

• Measurement technologyCalibration of audio equipment
• Music productionPortable audio effects
• educationDemonstration of audio signals
• PrototypingRapid development of audio concepts

results

The finished system offers:

• Frequency range: 20 Hz – 20 kHz
• Sampling rate: 44.1 kHz
• Bit depth: 16-bit
• Latency: <10 ms
• WiFi control with responsive web interface

Conclusion

This project demonstrates the versatility of the ESP32 for audio applications. The combination of powerful hardware and flexible software enables professional audio solutions at a fraction of the cost of commercial systems.

Interested in a similar project? Contact us for a personal consultation!