Retro Speaker Turned Bluetooth (Via ESP32)

I found this Panasonic RX-CW26 at an antique store and decided I wanted a nice speaker, but I wasn't going to use a speaker without Bluetooth, so I added Bluetooth. Nobody at the shop wanted another analog boombox, and the plastic case was already scuffed, so I was able to buy it for $20 Bucks. Instead of tossing it, I kept the speakers, the amp, and the 5-band graphic EQ, and gave it Bluetooth.

This project simply uses an ESP32 and a simple DAC to wirelessly transmit high-quality music.

Supplies

-Panasonic RX-CW26 portable stereo (or any boombox with rear RCA LINE IN)

-Solid Core Wire/Soldering equipment

-AAA Batteries with AAA cage

-ESP32 DevKit module with USB cable

-UDA1334A I2S DAC (https://www.amazon.com/dp/B0DRCN1HBV)

-RCA male screw-terminal plugs (https://www.amazon.com/California-JOS-Terminal-Adapter-Connector/dp/B0DTTJY74K)

If you don't have Arduino IDE yet, download it and set it up. When you are ready to go, you can download these board managers from GitHub, unzip them, and add them to your libraries.

Boards Manager URL

https://espressif.github.io/arduino-esp32/package_esp32_index.json

Board package

esp32 by Espressif Systems: ESP32 Dev Module/Devkit (Ensure you select this as your Board)

Libraries

https://github.com/pschatzmann/ESP32-A2DP

https://github.com/pschatzmann/arduino-audio-tools

Next, copy and paste this code into the IDE(Now you can upload it; this might take several minutes):

#include "AudioTools.h"

#include "BluetoothA2DPSink.h"

I2SStream i2s;

BluetoothA2DPSink a2dp_sink(i2s);

void setup() {

auto cfg = i2s.defaultConfig(TX_MODE);

cfg.pin_bck = 26;

cfg.pin_ws = 25;

cfg.pin_data = 22;

i2s.begin(cfg);

a2dp_sink.start("Boombox");

}

void loop() {

}

After uploading code to the board, use a flashlight battery holder or anything that will hold 3 batteries (in order to have about 4.5-5v) and solder a USB-C cord to the battery carriage.

You can also use any sort of corded power supply; just ensure you supply the ESP32 with 5 Volts

Solder your modules accordingly

ESP32 3V3 → UDA VIN

ESP32 GND → UDA GND

ESP32 D26 → UDA BCLK

ESP32 D25 → UDA WSEL

ESP32 D22 → UDA DIN

UDA Lout → LINE IN L

UDA Rout → LINE IN R

UDA GND → LINE IN GND

Now you can power the board, make sure the speaker has power, and connect it via bluetooth just like any other Bluetooth speaker.

Enjoy!