ESP32-S3 Voice Assistant Design

flux

I found suitable library parts for the requested ESP32-S3 voice-assistant board and will now create the schematic blocks with named rails/buses.

flux

Implemented the complete ESP32-S3 AI voice assistant schematic: ESP32-S3-WROOM-1-N16R8, USB-C native programming, TP4056 LiPo charging, 3.3 V LDO, OLED I2C, INMP441 mic, MAX98357A speaker amp, W25Q128 SPI flash, microSD SPI, reset/boot buttons, named nets, and support passives. ERC/passive/component checks returned no ERROR/WARNING/UNCERTAIN results.
Open items:
  • OLED library pin is labeled 5V but connected to 3V3; verify your actual 0.96" SSD1306 module supports 3.3 V VCC.
  • This is schematic-only; PCB placement/routing has not been done yet.
Suggested next steps:
  1. Place components and define board outline.
  2. Route USB, power, SPI, I2C, and I2S nets.
  3. Add test points for USB_VBUS, BAT, 3V3, GND, EN, and key buses.
  4. Review the docs: Project Specification, Board Bring-Up Plan, and Firmware Notes.
Layout, tests, review
Start PCB layout
Add test points
Fix OLED power
Check BOM cost

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Project Specification
Overview
Portable AI voice assistant development board inspired by Xiaozhi AI robot hardware.
Core Requirements
  • Main MCU/module: ESP32-S3-WROOM-1-N16R8
  • External 16 MB SPI NOR flash: W25Q128-class device
  • I2C 0.96 in SSD1306 OLED with SDA/SCL pull-ups
  • I2S MEMS microphone: INMP441-class
  • I2S Class-D amplifier: MAX98357A-class, driving 2-pin speaker terminal
  • microSD socket on shared SPI bus with dedicated CS
  • USB-C for 5 V input and native ESP32-S3 USB D-/D+ on GPIO19/GPIO20
  • TP4056 single-cell Li-ion charger with status LEDs and PROG current resistor
  • JST-PH 2-pin LiPo connector
  • 3.3 V LDO from BAT to board 3V3 rail
  • EN reset and GPIO0 boot buttons with RC debounce
Named Nets
USB_VBUS, BAT, 3V3, GND, USB_D-, USB_D+, I2C_SDA, I2C_SCL, SPI_SCK, SPI_MOSI, SPI_MISO, FLASH_CS, SD_CS, I2S_BCLK, I2S_LRCLK, I2S_MIC_SD, I2S_AMP_DIN, EN, BOOT.
Design Notes
The ESP32-S3-WROOM-1-N16R8 already includes 16 MB onboard flash and 8 MB PSRAM; the additional W25Q128 is implemented as asset/storage flash on a general SPI bus, not as boot flash.

  • Overview

  • Core Requirements

  • Named Nets

  • Design Notes

Documents

  • Project Specification

  • Board Bring-Up Plan

  • Firmware Notes

Assets

Assets are files uploaded to this project which can be used in various ways.

ESP32-S3 AI Voice Assistant Dev Board thumbnail
Portable ESP32-S3 AI voice assistant development board with USB-C programming, LiPo charging, OLED, I2S microphone/amplifier, SPI flash, and microSD expansion.

Properties

Properties describe core aspects of the project.

Pricing & Availability

Distributor

Qty 1

Arrow

$4.00–$7.98

Digi-Key

$9.53–$10.10

HQonline

$4.25–$4.39

LCSC

$35.61–$35.80

Mouser

$11.57

TME

$1.23

Verical

$4.49–$12.01

Controls