ESP32 MP3 Music Player with SD Card and I2S Amplifier

ESP32 MP3 Player reads MP3 and WAV audio files from MicroSD card and outputs audio through MAX98357A I2S amplifier driving 3W speaker. ESP32-AudioI2S library handles real-time MP3 decoding using dual cores. Web interface lets you browse files, play/pause/next/previous, adjust volume. Supported formats: MP3, AAC, FLAC, WAV, OGG. Also supports internet radio streams when WiFi connected. Physical controls: rotary encoder for volume, 3 push buttons. OLED display shows song title, progress bar, volume. SD card via SPI: GPIO5=CS, GPIO23=MOSI, GPIO19=MISO, GPIO18=SCK. I2S: GPIO25=BCLK, GPIO26=LRC, GPIO22=DIN. Libraries: ESP32-audioI2S, SD, SPI, U8g2.

Detailed Project Description

ESP32 MP3 Music Player with SD Card and I2S Amplifier focuses on a specific hardware interface or peripheral and shows exactly how to wire it, drive it from firmware and verify it is working.

How It Works
1. The peripheral is connected to the controller using the required bus (SPI/I2C/UART/I2S/CAN/RS-485/PWM/ADC).
2. The driver library is initialised and the peripheral configured.
3. Firmware exchanges data with the peripheral and processes it (measure, decode, render, play).
4. Results are verified on a display, serial monitor or the receiving device.

Key Components and Their Role
- ESP32: dual-core Wi-Fi + Bluetooth microcontroller that runs the firmware, reads the sensors and hosts the network connection.
- OLED display (SSD1306): 128x64 I2C display used to show live readings and status.
- I2S audio interface: digital audio bus used for microphones and amplifiers.
- microSD card module: storage for logs, audio or images over SPI.

Implementation Steps
1. Collect the components and study each module's datasheet (pin-out, voltage, interface).
2. Wire the circuit on a breadboard following the pin mapping; power sensors from the correct rail (3.3 V / 5 V).
3. Install Arduino IDE, ESP32-audioI2S Library, U8g2 Library and the required libraries; flash a minimal test sketch for each module separately.
4. Write the main firmware: read sensors → process → drive outputs / send data.
5. Configure network or cloud credentials and test communication end-to-end.
6. Calibrate thresholds, add error handling (reconnect, sensor time-out) and run a long-duration test.
7. Finalise on a PCB / enclosure and document wiring, code and results.

Key Features
- Correct wiring and bus configuration
- Driver setup
- Data processing
- Verification on real hardware

Expected Output
On completion the student will have a working peripheral that is measured/driven exactly as intended.

Deliverables
- Complete source code with comments
- Circuit diagram and pin mapping
- Project report with screenshots and results
- Demonstration-ready build