In this tutorial, we’ll build a simple Bluetooth audio Player using the ESP32. Once completed, you can stream music directly from your phone to a speaker through the ESP32
This project is perfect for:
- IoT learners
- Embedded beginners
- DIY audio enthusiasts
Components Required
- ESP32
- MAX98357A I2S amplifier module
- Speaker (4Ω or 8Ω)
- Jumper wires
- Breadboard (optional)
How It Works?
The ESP32 receives audio via Bluetooth (A2DP profile), then sends digital audio data through I2S to an amplifier.
Phone → Bluetooth → ESP32 → I2S → Amplifier → Speaker
Circuit Diagram
| ESP32 Pin | MAX98357A |
|---|---|
| GPIO14 | BCLK |
| GPIO15 | LRC (WS) |
| GPIO22 | DIN |
| GND | GND |
| 5V | VIN |
Required Libraries
Make sure you install on Arduino IDE:
- Arduino IDE
- ESP32 Board Package
- Library:
ESP32-A2DP - Library:
AudioTools
Code:
#include "AudioTools.h"
#include "BluetoothA2DPSink.h"
I2SStream i2s;
BluetoothA2DPSink a2dp_sink(i2s);
void setup() {
Serial.begin(115200);
// Configure I2S
auto cfg = i2s.defaultConfig();
cfg.pin_bck = 14; // BCLK
cfg.pin_ws = 15; // LRCLK
cfg.pin_data = 22; // DATA
i2s.begin(cfg);
// Start Bluetooth
a2dp_sink.start("MyMusic");
}
void loop() {
}Uploading the Code
- Connect ESP32 via USB
- Select Board: ESP32 Dev Module
- Choose correct COM port
- Click Upload
Connecting Your Phone
- Turn ON Bluetooth
- Search for “MyMusic”
- Connect to it
- Play any song
Your speaker should start playing audio wirelessly!