Hardware Guide

This guide covers the hardware components, bill of materials, and assembly path for a LongWave Audio endpoint.

Bill of Materials

ComponentDescriptionLink
XIAO ESP32-S3 PlusMicrocontroller for each endpoint.Seeed Studio
Wi-Fi HaLow moduleWio-WM6180 or custom mm8108 PCB.See options below.
Audio DAC hatCustom I2S PCB.OSHWLab
Enclosure3D printed two-part case.OnShape
SpeakerPassive or active speaker.User choice.
Power supplyUSB-C or battery supply.User choice.

Server-side hardware: Any Linux-capable device can run the server, including a Raspberry Pi, old laptop, NAS, or VM, provided it has network access to the Wi-Fi HaLow AP or bridge.

Microcontroller

The Seeed Studio XIAO ESP32-S3 Plus is the endpoint controller. The Plus variant is required because it has the pre-soldered 40-pin connector used by the Audio DAC hat.

Wi-Fi HaLow Options

Option A: Seeed Wio-WM6180

An off-the-shelf XIAO add-on module using the FGH100M chipset. It is the fastest path for a first build.

Purchase from Seeed Studio

Option B: Custom PCB

An open hardware OSHWLab / EasyEDA design based on the mm8108 board path.

View the OSHWLab project

Audio DAC Hat

The DAC hat is a custom open-hardware PCB that connects to the ESP32-S3 through I2S and provides stereo analogue output. It is available on OSHWLab for direct fabrication ordering, or you can manufacture it yourself using the files below.

Hardware files (v1.1):

Endpoint Stack

  1. Bottom: XIAO ESP32-S3 Plus microcontroller.
  2. Middle: Wi-Fi HaLow module, either Wio-WM6180 or custom PCB.
  3. Top: Audio DAC hat.

Assembly Steps

  1. Attach the Wi-Fi HaLow module to the XIAO ESP32-S3 Plus. For Wio-WM6180, use the snap-on socket. For the custom PCB, solder standard 2.54 mm pitch connectors and trim flush.
  2. Connect the DAC hat through the header.
  3. Power the endpoint through USB-C on the XIAO board.
  4. Connect speakers or an amplifier to the DAC hat output.

Prototype Photos

The current endpoint prototype stacks the ESP32-S3 carrier, HaLow board, and audio DAC hardware into a compact assembly. The enclosure files in this repository are early 3D print parts for the case shown below.

LongWave endpoint board beside a blue prototype enclosure with antenna
Prototype board next to a printed enclosure with antenna.
Isometric view of the assembled LongWave endpoint board stack
Assembled endpoint stack — XIAO ESP32-S3 Plus, HaLow module, and DAC hat.
Top-down view of the LongWave audio endpoint with SMA and 3.5 mm jack
Top-down view: SMA antenna connector and 3.5 mm audio output.

Enclosure

The enclosure is a two-part 3D printed case. The CAD source is on OnShape — copy the document to make your own edits. STL files for direct printing: