What is it

Louder ESP Audio Dock is a combination of an external I2S DAC capable of driving full-size speakers (I mean grown-up home stereo) and a PSRAM chip. This combination provides your compact ESP32 module with both the necessary memory and capabilities to develop Hi-Fi products.

Motivation

Over the past few years, I dedicated my time to developing various solutions using ESP devices. It all began with the ESP8266, which had limited CPU power, restricting it to basic tasks like simple sound alerts. However, with the arrival of the ESP32, everything changed. This new model brought two significantly more capable cores, providing a powerhouse for handling communication and real-time decoding simultaneously. Furthermore, the inclusion of 4MB of PSRAM proved to be crucial, enabling effective buffering for streamed content.

I developed a diverse selection of ESP32 docks that allow for rapid prototyping across the entire spectrum of ESP32 chips. These docks cater to various needs, ranging from small, compact devices resembling toys to large, full-sized speakers. The Louder ESP is a high-end Hi-Fi powerhouse, offering top-of-the-line performance and capabilities.

Features

	ESP Audio Solo	ESP Audio Duo	Hifi ESP	Louder ESP
Image
Docks with	ESP8266, ESP32C3, ESP32S2 Mini modules	ESP32 Mini Module	ESP32 Mini Module	ESP32 Mini Module
DAC	Single I2S DAC (MAX98357) with built in D-Class amp	Dual I2S DAC (MAX98357) with built in D-Class amp	PCM5100A 32bit Stereo DAC -100 dB typical noise level	Stereo I2S DAC (TAS5805M) with built in D-Class amp
Output (4Ω)	3W	2x 3W	Non-amplified stereo output	2x 15W at 12V Vin
Output (8Ω)	1.5W	2x 1.5W	Non-amplified stereo output	2x 23W at 22V Vin
Adds		8MB PSRAM (4MB usable)	8MB PSRAM (4MB usable)	8MB PSRAM (4MB usable)

Onboard PSRAM

Audio streaming requires proper buffering to work, even with ESP32 500K of RAM it is a challenging task. For that reason, most of the projects will require WROVER modules that have onboard PSRAM IC.

Louder ESP has an 8MB PSRAM chip onboard, connected via a high-speed SDIO interface. This effectively turns your regular WROOM module into a WROVER module with no effort required. Any code using PSRAM will just work out-of-the box.

Board Pinout

Starting from revision E, Louder ESP exposes an Ethernet header, compatible with the popular W5500 module

Software samples

In the software section two firmware examples are provided.

• esp32-i2s-bare is base I2S implementation based on ESP-IDF implementation directly.
• esp32-i2s-esp8266audio is based on excellent ESP8266Audio library (it works with the whole ESP range, don't get fooled by the name), providing minimum code implementation.
• esp32-i2s-web-radio is based on the same library, providing minimum web-readio stream player. It expects a playlist as an input in the 'data' folder.

Platformio IDE

All samples are provided as Plarformio IDE projects. After installing it, open the sample project. Select the proper environment based on your dock. Run the Build and Upload commands to install necessary tools and libraries, and build and upload project to the board. Communication and proper upload method selection will be handled by IDE automatically.

Arduino IDE

Follow the ESP8266Audio library guide. Default settings will work out of the box with ESP8266 and ESP32 boards. For ESP32C3 and ESP32S2 board please adjust pinout according to the above section

Squeezelite-ESP32

Squeezelite-ESP32 is a multimedia software suite, that started as a renderer (or player) of LMS (Logitech Media Server). Now it is extended with - Spotify over-the-air player using SpotifyConnect (thanks to cspot) - AirPlay controller (iPhone, iTunes ...) and enjoy synchronization multiroom as well (although it's AirPlay 1 only) - Traditional Bluetooth device (iPhone, Android)

And LMS itself - Streams your local music and connects to all major online music providers (Spotify, Deezer, Tidal, Qobuz) using Logitech Media Server - a.k.a LMS with multi-room audio synchronization. - LMS can be extended by numerous plugins and can be controlled using a Web browser or dedicated applications (iPhone, Android). - It can also send audio to UPnP, Sonos, Chromecast, and AirPlay speakers/devices.

All ESP32-based boards are tested with Squeezelite-ESP32 software, which can be flashed using nothing but a web-browser. You can use Squeezelite-ESP32 installer for that purpose.

How to flash and configure ("ESP Audio Duo", "HiFi-ESP" and "Louder ESP")

Use Squeezelite-ESP32 installer to flash firmware first.

Use Generic/I2S profile
Connect the device to USB port and select it from the list
Press Flash and wait around 2 minutes
(Optional) You may enter the serial console to get more information
Device is in recovery mode. Connect to squeezelite-299fac wifi network with squeezelite password (your network name suffix will be different)
When redirected to the captive portal let the device scan the wifi network and provide valid credentials
You can use provided IP address (http://192.168.1.99/ on the screenshot) to access settings page
ESP Audio Duo, HiFi-ESP Navigate to Hardware section and provide following updates in the DAC Options DAC model: I2S Clock GPIO: 26 Word Select GPIO: 25 Data GPIO: 22 Press Save button
["Louder ESP"] Navigate to NVS Editor section and provide following updates dac_config:  model=I2S,bck=26,ws=25,do=22,sda=21,scl=27,i2c=45  dac_controlset:  {"init":[{"reg":3,"val":2},{"reg":3,"val":3}],"poweron":[{"reg":3,"val":3}],"poweroff":[{"reg":3,"val":0}]}  i2c_config: scl=27,sda=21,speed=400000,port=1  set_GPIO: 33=vcc Press Commit button
(Optional) You may change device names to something close to your heart
Exit recovery

You can use it now

Bluetooth	Spotify Connect	AirPlay	LMS Renderer

Hardware

Please visit hardware section for board schematics and PCB designs. Note that PCBs are shared as multi-layer PDFs.

The Dock

Image	Legend
(Rev A)	TAS5805M DACSpeaker Terminals8MB PSRAM IC3V3 Drop-Down voltage regulator (powers ESP32)Input Voltage terminal
(Rev B)	TAS5805M DACSpeaker Terminals - 8MB PSRAM IC (Hidden under ESP32 module) - 3V3 Drop-Down voltage regulator (powers ESP32, hidden under ESP32 module)Input Voltage terminal

Louder Optional SPI Ethernet module

Image	Legend
Optional Ethernet header is exposed on the bottom side of the PCB
Use popular W5500 based module as displayed on the picture