Introduction

The E-Speaker is a smart, portable, and versatile audio system built using the ESP32 microcontroller. Leveraging the ESP32’s Wi-Fi and Bluetooth capabilities, this project creates an affordable and efficient smart speaker capable of streaming music, playing audio files, and providing basic voice assistant functionalities.

Features

Wireless audio streaming via Bluetooth and Wi-Fi

Support for multiple audio formats (MP3, WAV, etc.)

Integration with online music services (e.g., Spotify, internet radio)

Compact and portable design

Voice command support using a microphone

Control via a smartphone app or web interface

Block Diagram

Block diagram of ESP 32 Based Audio Player

Audio Files and Arduino IDE Audio Files

This is the most important part of this project. To play audio sounds on the ESP32 board, we need audio files in .wav format because ESP32 can play an audio file in .wav format only.

First of all we must be make the audio file ready that we want to play in our speaker. You can also record your own audio file in this case.

After that, download and install the Audacity Audio Editor App. This app will be used to change the file type, Sample Rate, and other properties.

Audacity

Once the installation is complete, open the Audacity app and then go to file > Open and select the audio file to edit.

Audacity

The first thing that needed to be changed is the sampling rate. For playing an audio file on ESP32, a sampling rate of 8000 to 16000 will be good as ESP32 doesn’t have much memory. So change the Project Rate to 16000.

Audacity

After that, navigate to File > Export > Export as WAV to save the audio file in .wav format.

Audacity

Now in the next window, select WAV  as file type and Unsigned 8-bit PCM as an Encoding format and then click on Save.

Audacity

Now we need a Hex Editor app to generate Hex codes for the audio file. So download and install the Hex Editor (HxD) from the given link. We can also use any hex editor as per the comfort. I have used editor in my case. After that, open the app, then go to File > open and open the .wav file. This will generate the Hex code for the .wav file.

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Then use ctrl+A to select the complete code and then go to Edit > Copy as > C to copy the code in C Language format.

hex editor

Then paste this code into sound.h part in Arduino IDE.

Coding

We are using ESP-32 as our main controller so, we must add esp 32 board from board manager of arduino IDE.

ESP-32 Board link for Arduino IDE : https://dl.espressif.com/dl/package_esp32_index.json

Here, we are going to use the XT DAC Audio library from XTronical. The XT DAC Audio library can be downloaded from here.

Once you download XT DAC Audio library in zip format you must add the library in your arduino IDE.

Setting audio library in arduino IDE

Once you add the library, you can conform weather the library is added to arduino IDE by going to example section.

Setting audio library in arduino IDE

If it is successfully added, you can see XT_DAC_Audio at the end of the example section. You can also open and upload wavspeed code to test weather the hardware is properly functioning or not.

It contain two file Wavspeed main file and sound.h file. Wavspeed contain the main code and sound.h contain the hex code of the audio file.

main file

sound.h file

select the respective board and port from the arduino IDE. Upload the code to esp 32 and enjoy with the audio output in your speaker.

Setting audio library in arduino IDE

Adding your own audio file

If you want to add your own audio file then you can download the code below:

codeDownload

Once you extract this you can two file here:

open code.ino file

Go to sound.h section. and replace it with the respective audio hex code. I have already discussed how we generate audio hex code above:

once you paste your hex file in sound.h section. make sure your data type must be const unsigned char as below:

PCB File

3d View

Real PCB

Conclusion

The E-Speaker using ESP32 is a cost-effective and feature-rich project that combines the power of modern microcontrollers with smart audio functionality. It is ideal for DIY enthusiasts looking to explore IoT and audio electronics. With its scalability and flexibility, the project opens the door to numerous enhancements and integrations.