Hardware Requirements:

• Original ESP32/WROOM-32 with Bluetooth Classic
• PCM5102A DAC
• Arduino IDE

What we are Building

• Bluetooth A2DP receiver
• Stereo bass, mid and treble EQ
• Flat, Rock, Jazz and Classical presets
• Serial control for initial tuning

It uses the current ESP32-A2DP and Arduino Audio Tools approach. ESP32-A2DP receives SBC audio as 16-bit stereo PCM, and Audio Tools provides the I²S output layer.

Required Libraries

In Arduino IDE → Library Manager, install:

• ESP32-A2DP by Phil Schatzmann
• Arduino Audio Tools by Phil Schatzmann
• btAudio - https://github.com/tierneytim/btAudio#c

Select an original ESP32 board, such as ESP32 Dev Module. The ESP32-S3 and C3 are unsuitable because they do not support Bluetooth Classic A2DP.

Pinout

If exposed:

• FMT → GND for standard I²S
• XSMT → 3.3 V for unmuted operation
• SCK → GND on the common PLL-equipped modules

These pin assignments correspond to the established ESP32-A2DP PCM5102 setup.

Code

Using btAudio

#include <btAudio.h>

// Sets the name of the audio device
btAudio audio = btAudio("ESP_Speaker");

void setup() {
 
 // Streams audio data to the ESP32   
 audio.begin();
 
 // Re-connects to last connected device
 audio.reconnect();
 
 // Outputs the received data to an I2S DAC, e.g. https://www.adafruit.com/product/3678
 int bck = 26; 
 int ws = 27;
 int dout = 25;
 audio.I2S(bck, dout, ws);
}

void loop() {

}

References