What is it

Louder ESP Audio Dock combines 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 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, simultaneously providing a powerhouse for handling communication and real-time decoding. 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 ESP32 (Rev H)	Louder ESP32-S3 (Rev J)
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Docks with	ESP8266, ESP32C3, ESP32S2 Mini modules	ESP32 Mini Module	ESP32 Mini Module	ESP32-WROVER-N16R8 onboard	ESP32-S3-WROOM-N16R8 onboard
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	Stereo I2S DAC (TAS5805M) with built in D-Class amp
Output (4Ω)	3W	2x 3W	Non-amplified stereo output	2x 32W (4Ω, 1% THD+N)	2x 32W (4Ω, 1% THD+N)
Output (8Ω)	1.5W	2x 1.5W	Non-amplified stereo output	2x 22W (8Ω, 1% THD+N)	2x 22W (8Ω, 1% THD+N)
Adds		8MB PSRAM (4MB usable)	8MB PSRAM (4MB usable)	8MB PSRAM (4MB usable)	8MB PSRAM (all usable, and use faster interface)
Connectivity	WiFi (ESP8266, ESP32S2) WiFi + BT5.0 (ESP32C3)	WiFi + BT4.2 + BLE	WiFi + BT4.2 + BLE	WiFi + BT4.2 + BLE Ethernet	WiFi + BLE Ethernet (No Bluettoth Classic)
Software support	Arduino samples, ESPhome config	Arduino samples, squeezelite-esp32, snapcast, ESPhome config	Arduino samples, squeezelite-esp32, snapcast, ESPhome config	Arduino samples, squeezelite-esp32, snapcast, ESPhome config	Arduino samples, squeezelite-esp32 (experimental build), ESPhome config

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 the 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 the pinout according to the above section

ESPHome and Home Assistant

Being an ESP32-based device, you can easily integrate it into your Home Assistant using ESPHome. Start with esphome web installer, which will give you ESPHome base install and WiFi configuration in minutes. Some S2/S3 boards have issues with we-installer, you may need to use Adafruit flasher instead with binaries pulled from the HA.

Next, navigate to your Home Assistant (assuming you have your ESPHome integration installed), and adopt the newly created node

ESPHome will give you ESPHome configs for Solo board running with ESP32-S2/S3, as well as Duo/HiFi-ESP and Louder ESP working with ESP32.

Few words of explanation.

• media_player publishes the media player into the Home assistant, so you can use it together with the native player or Music Assistant. You have a volume knob in the HA as well.
• 
• Volume set up to 50% on player start. Especially for Louder-ESP32, this is helpful :)

Bonus - automation example

The true power of the native speaker in the eHA is the use of automation. One example that I find useful. This simple automation will be pronounced every hour between 8 AM and 9 PM. Another one is used to pronounce bedtime, you get the point...

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 Installer for ESP Audio Dock to flash firmware first. It has been preconfigured to work with ESP Audio boards and will configure all hardware automatically.

Select the correct device first
Connect the device to the 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 wifi network and provide valid credentials
You can use provided IP address (http://192.168.1.99/ on the screenshot) to access settings page
(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 the hardware section for board schematics and PCB designs. Note that PCBs are shared as multi-layer PDFs.

Louder ESP

Image	Legend
	TAS5805M DAC Speaker Terminals 8MB PSRAM IC 3V3 Drop-Down voltage regulator (powers ESP32) Input Voltage terminal
(REV B, C, D)	TAS5805M DAC Speaker Terminals - 8MB PSRAM IC (Hidden under ESP32 module) - 3V3 Drop-Down voltage regulator (powers ESP32, hidden under ESP32 module) Input Voltage terminal

Louder ESP32 (rev H)

Image

Louder ESP32-S3 (rev J)

Image

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

BTL and PBTL mode

TAS5805M DAC Allows 2 modes of operation.

	BTL	PBTL
Descriotion	Bridge Tied Load, Stereo	Parallel Bridge Tied Load, Stereo
Rated Power	2×23W (8-Ω, 21 V, THD+N=1%)	45W (4-Ω, 21 V, THD+N=1%)
Schematics
Speaker Connection

Starting from Rev E, an additional header is exposed to allow datasheet-speed connectivity

Image	Legend
Stereo Mode - leave open
Mono (PBTL) Mode, close horisontally

Louder ESP power considerations

Barrel jack used is spaced at 6mm hole/2mm pin, which is typically 5.5/2.5mm jack on the male side.

The screw terminal is connected parallel to the barrel jack, you can use either interchangeably.

The power adapter specs depend on the speaker you're planning to use. DAC efficiency is close to 100%, so just take the power rating of your speaker (say 2x10w), and impedance (say 8 ohms) and you'd need at least 9 volts rated at 1.2 amps per channel, round up to 3 total amps.

It is not recommended to go beyond the voltage your speakers can take, otherwise amp will blow your speakers in no time.

Important: do not connect Vin and USB-C at the same time, or you will cook your USB-C port! I didn't want to lose voltage on the voltage-select circuit, so these two sources are connected. While developing and debugging, a USB-C power source will be sufficient to run DAC with a power limit of ~5W per channel.

Case

Louder-ESP32 is mechanically compatible with Raspberry Pi 3/4 cases, tested with transparent ones (last photos in the gallery). Also, community members created a few 3-D printable designs that can be found here and here