ESP32 Audio Docks and Louder ESP

ESP32 Audio Docks is a range of extension boards (i.e. docks) that allow you to develop Audio solutions based on ESP32 chips. These were created to make Audio development entry as easy and inexpensive as possible.

Motivation

I spent last few years developing different solutions based on ESP delices. It all started with ESP8266, where CPU power is not really sufficient to do real-time decoding, so you're limited to rather simple ding-dong business. Then ESP32 came, bringing two much more capable cores, so you have powerhouse to handle communication and decoding at the same time. Perhaps most importantly it also came with SPIRAM, so you can do decent buffering (essential for streamed content).

Now new ESP32 C-Series and S-Series chips are entering the market, and their potential is mostly unrealized as for today.

I created those docks, to be able quick prototype for whole range of ESP8266 and ESP32 chips, starting with the simplest finger-sized toys and going all the way up to full-sized speakers.

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)
Connectivity	WiFi (ESP8266, ESP32S2) WiFi + BT5.0 (ESP32C3)	WiFi + BT4.2 + BLE	WiFi + BT4.2 + BLE	WiFi + BT4.2 + BLE Ethernet

Onboard PSRAM

Audio streaming require 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 chip.

All ESP32 Docks has 8MB PSRAM chip onboard, connected via high-speed SDIO interface. This effectively turns your regular WROOM module into WROVER module with no effort required. Any code using PSRAM with just work out-of-the box.

Boards Pinout

ESP Audio Solo

	I2S CLK	I2S DATA	I2S WS
ESP8266	15	3	2
ESP32C3	5	20	6
ESP32S2	12	37	16

ESP Audio Duo

	I2S CLK	I2S DATA	I2S WS	PSRAM CE	PSRAM CLK
ESP32	26	22	25	16	17

HiFi-ESP

	I2S CLK	I2S DATA	I2S WS	PSRAM CE	PSRAM CLK
ESP32	26	22	25	16	17

Louder ESP

	I2S CLK	I2S DATA	I2S WS	PSRAM CE	PSRAM CLK	TAS5805 SDA	TAS5805 SCL	TAS5805 PWDN	TAS5805 FAULT
ESP32	26	22	25	16	17	21	27	33	34

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

	SPI CLK	SPI MOSI	SPI MISO	SPI CS	SPI HOST/SPEED	ETH INT	ETH RST
ESP32	18	23	19	05	2/20MHz	35	14

Software samples

In the software section two firmware examples 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 playlist as an input in 'data' folder.
• Squeezelite-ESP32 - see more details below

Platformio IDE

All samples are provided as Plarformio IDE projects. After installing it, open sample project. Select proper environment based on your dock. Run Build and Upload commands to install necessary tools and libraries, build and upload prject 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 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 connect to all major on-line 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, that can be flashed using nothing but 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 device to USB port and select if from the list
Press Flash and wait around 2 minutes
(Optional) You may enter 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 captive portal let 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
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 (STEREO, BTL mode) dac_controlset: {"init":[{"reg":3,"val":2},{"reg":3,"val":3}],"poweron":[{"reg":3,"val":3}],"poweroff":[{"reg":3,"val":0}]} (MONO, PBTL mode) dac_controlset: {"init":[{"reg":3,"val":2},{"reg":3,"val":3},{"reg":2,"val":4}],"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
Louder ESP, Rev E Update Ethernet configuration, if you're planning to use Ethernet module eth_config: model=w5500,cs=5,speed=20000000,intr=35,rst=14 spi_config: mosi=23,clk=18,host=2,miso=19 Press Commit button
(Optional) You may change device names to something close to you 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 PCB are shared as multi-layer PDFs.

ESP Audio Solo

Image	Legend
	MAX98357 DAC Speaker Terminal

ESP Audio Duo

Image	Legend
	MAX98357 DAC Speaker Terminals 8MB PSRAM IC

HiFi-ESP

Image	Legend
	PCM5100A DAC Speaker Terminals 8MB PSRAM IC Ultra-Low noise LDO 3V3 Voltage regulator

Louder ESP

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	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 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, additonal header is exposed to allow datasheet-speced connectivity

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

Louder ESP power considerations

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

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), impedance (say 8 ohm) 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 voltage your speakers can take, otherwise amp will blow you speakers in no time.

Where to buy

You may support my work by ordering these product at Tindie

• ESP Audio Dock
• Louder ESP32