XIAO ESP32S3 Plus

A feature-rich variant of the XIAO ESP32S3, offering expanded memory and interfaces for complex applications.

USB-C Native USB
XIAO ESP32S3 Plus board
21 × 17.8 mm
ESP32-S3
MCU
240MHz
clock
16MB
flash
512KB
SRAM
11· 9 ADC
GPIO
BLE 5.0+ WiFi
radio
On this page

Pinout

14 pins · 2.54 mm pitch
View:
XIAO ESP32S3 Plus pinout diagramXIAO ESP32S3 Plus pinout diagram (alternate view)
PinGPIOLabelsStatusCapabilitiesNotes
11D0A0GPIO1safeadc · pwm
22D1A1GPIO2safeadc · pwm
33D2A2GPIO3strappingadc · pwm
44D3A3GPIO4safeadc · pwm
55D4A4SDAGPIO5safeadc · pwm · i2c
66D5A5SCLGPIO6safeadc · pwm · i2c
743D6TXGPIO43strappinguart · pwm
8-5Vpower-5V power input/output
9-GNDground-
10-3V3power-3.3V power
119D10A10MOSIGPIO9strappingadc · pwm · spi
128D9A9MISOGPIO8safeadc · pwm · spi
137D8A8SCKGPIO7safeadc · pwm · spi
1444D7RXGPIO44strappinguart · pwm

Start with these

7 pins with no boot or system involvement
D0A0D1A1D3A3D4A4D5A5D9A9D8A8

Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.

Fine - with a little care

sampled at boot or shared with debug/serial
PinLabelWhat to knowRole
D2GPIO3Sampled at reset to select JTAG interface (USB Serial/JTAG controller vs. external pins). Improper use can disable external JTAG or alter debug interface.Strapping
D6U0TXD (GPIO43)Used for bootloader output and UART console logs. If repurposed, you will lose the default serial output (and programming via UART0).Other
D7U0RXD (GPIO44)Used for bootloader input (download mode via serial). If repurposed, you cannot use the default UART0 download mode for programming the chip.Other

Only if you know the tricks

wired to flash or USB - expect a fight
PinLabelWhat to knowRole
D10FSPIHDConnected to external flash (data/hold signal) on most modules. Not recommended for use as GPIO, since it must remain dedicated to flash communication.Flash
These are recommendations, not hard rules - with the right pull-ups, timing and boot-state awareness most pins can be made to work. When in doubt, start green.
Pinout notes Across 14 pins (2.54 mm pitch), the XIAO ESP32S3 Plus exposes 11 GPIO plus 5V , GND and 3V3 for power. For peripherals, I²C is mapped to SDA on GPIO5 and SCL…

Across 14 pins (2.54 mm pitch), the XIAO ESP32S3 Plus exposes 11 GPIO plus 5V, GND and 3V3 for power.

For peripherals, I²C is mapped to SDA on GPIO5 and SCL on GPIO6; the SPI bus (MOSI, MISO, SCK) is broken out in full; TX/RX on GPIO43 and GPIO44 cover serial logging and flashing.

On the analog side there are 9 ADC-capable pins for sensors and battery monitoring and PWM on every GPIO.

If you want zero surprises, D0, D1, D3, D4 and 3 more are free of any such role - the safest first picks. 3 of the exposed pins carry boot-time or system duties on the ESP32-S3 (D2, D6 and D7).

Getting started

flash your first firmware in ~2 minutes
Tool:
1
Connect over USB
Native USB - no driver, no serial chip. Not detected? Hold BOOT while plugging in.
2
Flash with your tool
Arduino IDE, PlatformIO, ESPHome or esptool - copy the settings on the right.
3
Verify it runs
The blink example uses GPIO1 - swap for your board's LED pin if different.
Tools → Board settings Copy
Board:            Xiao Esp32s3 Plus
USB CDC On Boot:  Enabled
Flash Size:       16MB · QIO
Upload Speed:     921600

// blink
pinMode(1, OUTPUT);
digitalWrite(1, LOW);   // on (often inverted)
platformio.ini Copy
[env:xiao-esp32s3-plus]
platform = espressif32
board = esp32-s3-devkitc-1
framework = arduino
monitor_speed = 115200
upload_speed = 921600
device.yaml Copy
esp32:
  board: esp32-s3-devkitc-1
  variant: XIAO_ESP32S3_PLUS
  framework:
    type: esp-idf

# blink - GPIO1
output:
  - platform: gpio
    pin: 1
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out
shell Copy
esptool.py --chip esp32s3 --port /dev/ttyACM0 \
  write_flash 0x0 firmware.bin
Build details: sketch space 8388608 B · data 327680 B · QIO

Good to know

board-specific quirks worth 60 seconds
XIAO ESP32S3 Plus illustration

Specifications

ESP32-S3 · 21 × 17.8 mm
Compute
MCU
ESP32-S3
Clock
240 MHz
SRAM · Flash
512 KB · 16MB · 8MB (OPI) PSRAM
Radio
Wi-Fi
802.11 b/g/n
Bluetooth
5.0 LE
Antenna
External
I/O
GPIO · ADC
11 · 9
UART · I²C · SPI
3 · 2 · 4
PWM
8 channels
Power
USB
USB-C
Serial
Native (CDC)
Boot address
0x0
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
QIO · QIO
Sketch · Data
8 MB · 320 KB
17.8 mm21 mm
21 × 17.8 mm · pin pitch 2.54 mm
The XIAO ESP32S3 Plus uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is QIO with QIO boot mode. The maximum sketch size is 8 MB with 320 KB available for data.

About this board

At 21 × 17.8 mm it's among the smallest boards in the whole ESP32 family.

At its core is the ESP32-S3 - a dual-core Xtensa with vector extensions suited to AI workloads.

Expect to pay about $20.00 - less than the ~$30 most ESP32-S3 boards go for.

The small footprint costs pins: 11 GPIO are broken out, versus 21 or so on a full-size board.

Onboard you'll find 8MB (OPI) PSRAM, a microSD slot, battery charging via Solder pads, status LEDs (User, Charge) and Reset/Boot buttons.

It flashes over native USB - no serial-converter driver needed, which isn't a given among ESP32-S3 boards.


The XIAO ESP32S3 Plus is a high-performance development board based on the ESP32-S3 dual-core processor with enhanced features. It supports WiFi 4 and Bluetooth 5 (LE), making it ideal for IoT, AI, and embedded applications.

With a compact yet powerful design, it includes a USB-C port for fast programming and power, and features additional onboard peripherals such as external PSRAM and additional castellated I/O.

The XIAO ESP32S3 Plus supports multiple communication interfaces, including UART, I2C, SPI, and ADC, making it a great choice for advanced embedded applications.
  • Dual-core Xtensa LX7 processor with enhanced AI capabilities
  • 8MB PSRAM + 16MB flash and extra broken-out GPIO pins vs the standard XIAO ESP32S3
  • Supports WiFi 4 and Bluetooth 5 (LE)
  • Ultra-small size (21x17.5 mm)

Where to buy

prices are typical street prices
XIAO ESP32S3 Plus
XIAO ESP32S3 Plus
$20.00per unit, typical

Resources

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