What is it

Loud Esparagus is a compact media center device aimed to be paired with small-to-medium-sized speakers in a small room. It uses a dual MAX98357 Hi-Fi DAC that will output 3W per speaker. Admittedly not much, but well enough for a kid's room or workplace. Due to the D-class amp, it barely uses power and can be paired with a standard USB wall charger.

Motivation

I did few audio projects in the past, some using ESP32, some using larger Orange Pi and Raspberry Pi devices. Each has its pros and cons, and with each iteration, I'm trying to focus on the details that were working best for me, while actually using them.

What I like about ESP32 is how lightweight it is. It barely draws power, so you may not care to turn it off at all. It boots in seconds and is ready for use in a snap. Still, it is capable and works at par with Linux SBC solutions for audio applications while costing a fraction of their price. Combined with a proper Hi-Fi DAC, you would not be able to tell the difference between it and commercial devices standing side by side and costing much more.

Over the last few years, I have seen a few amazing software products created to deliver audio on the ESP32, like squeezelite-esp32 or  euphonium. Esparagus HiFi MediaLink is designed specifically to run these great pieces of software and bring a new life into aging audio equipment that most of us have at home, but do not use that much these days, since it is not working with Spotify and the family.

Features

	HiFi Esparagus	Loud Esparagus	Louder Esparagus
Image
MCU	ESP32-WROVER-N8R8	ESP32-WROVER-N8R8	ESP32-WROVER-N16R8
DAC	PCM5100A 32bit Stereo DAC -100 dB typical noise level	Dual I2S DAC (MAX98357) with built-in D-Class amp	Stereo I2S DAC (TAS5805M) with built-in D-Class amp
Output	Non-amplified stereo output, 2.1V RMS	2x 5W (4Ω), 2x 3W (8Ω)	2x 32W (4Ω, 1% THD+N), 2x 22W (8Ω, 1% THD+N)
Power	5V over USB-C, 2x LP5907 3.3 V Ultra-Low-Noise LDO for analog section	5V (up to 2.5A) from USB-C	Up to 20V from USB-C PD (PD version); Up to 26V from external PSU (NOPD version)
PSRAM	8MB PSRAM (4MB usable)	8MB PSRAM (4MB usable)	8MB PSRAM (4MB usable)
Connectivity	WiFi + BT4.2 + BLE	WiFi + BT4.2 + BLE	WiFi + BT4.2 + BLE; W5500 Ethernet
Size	80 x 50 x 20mm	80 x 50 x 20mm	100 x 80 x 38mm
Software support	Arduino samples, squeezelite-esp32, snapcast, ESPhome config	Arduino samples, squeezelite-esp32, snapcast, ESPhome config	Arduino samples, squeezelite-esp32, snapcast, ESPhome config

Onboard PSRAM

Audio streaming requires proper buffering to work, even with ESP32 500K of RAM it is a challenging task. Esparagus HiFi MediaLink is based on a WROVER module that has an onboard PSRAM chip.

Board Pinout

Audio

Peripheral

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 the 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 a minimum web-radio 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.

ESPHome and Home Assistant

Being an ESP32-based device, you can easily integrate it into your Home Assistant using ESPHome. Please find detailed instructions in the linked repo

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. More details and setup instructions can be found here

Hardware

Loud Esparagus

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

Boxed

Loud Esparagus

PCB

Loud Esparagus