Reference

AI-S3 Pinout

The pin reference for the AI-S3, an ESP32-S3-WROOM-1 development board with dual USB-C, native USB and an onboard addressable RGB LED.

21 september 2026 2 min read

The AI-S3 is an ESP32-S3 development board: dual USB-C ports, an onboard WS2812 RGB LED, and a full GPIO breakout on a compact board. This site’s AI-C3 board covers the same family’s RISC-V sibling, this is the Xtensa LX7, AI-accelerated version. This guide covers the AI-S3’s real pinout: what’s confirmed from the board’s own documentation, and what needs checking against Espressif’s own ESP32-S3 datasheet before you rely on it.

System-on-chip and module

The ESP32-S3 is Espressif’s dual-core, 240MHz Xtensa LX7 chip, with Wi-Fi 802.11 b/g/n, Bluetooth 5 (LE), and vector instructions aimed at edge-AI workloads (face/audio detection).

The board is built on the ESP32-S3-WROOM-1 module: flash, PSRAM, crystal and antenna in one shielded package.

The AI-S3 dev board breaks the module’s GPIOs out to a labeled header, adds BOOT and RESET buttons, two USB-C connectors (one for flashing, one for native USB OTG), and an onboard WS2812 RGB LED for status feedback, all on a compact purple PCB.

Key features

Dual-core 240MHz Xtensa LX7
Wi-Fi 802.11 b/g/n, Bluetooth 5 LE
Native USB (device and host/OTG)
14 capacitive touch GPIOs
Two 12-bit ADCs
Up to 20 PWM-capable channels
SPI, UART, I²C, I2S, RMT
Secure boot and flash encryption support
Onboard WS2812 RGB LED on GPIO48

GPIO quick reference

The pins this board’s own documentation calls out specifically, not an exhaustive list of every GPIO the ESP32-S3-WROOM-1 module exposes, check Espressif’s own ESP32-S3 datasheet for the complete pin map before a board-spanning design.

GPIO	Function	ADC	Touch	Notes
0	BOOT strap, touch	No	Yes	Hold low at reset to enter flash mode
1–10	ADC1, several also touch	Yes	Yes (0–13 range)
8	I²C SDA (suggested default)	Yes	Yes	Remappable with `Wire.begin(SDA, SCL)`
9	I²C SCL (suggested default)	Yes	Yes	Remappable
19	USB D+	No	No	Native USB, avoid using as plain GPIO
20	USB D−	No	No	Native USB, avoid using as plain GPIO
34	SPI CS (suggested default)	No	No
35	SPI MOSI (suggested default)	No	No
36	SPI CLK (suggested default)	No	No
37	SPI MISO (suggested default)	No	No
43	UART0 TX	No	No	To onboard USB-serial, to your PC
44	UART0 RX	No	No	From onboard USB-serial, from your PC
48	WS2812 RGB LED	No	No	Built-in, addressable

Avoid ADC2 (GPIO11–20) while Wi-Fi is active, the two share internal resources and readings can be unreliable during a Wi-Fi connection.

Programming

Any of Arduino IDE (with ESP32-S3 board support), PlatformIO, or ESP-IDF works. The left-hand USB-C port is the one wired to the onboard USB-serial converter, used for flashing and the serial monitor. The second USB-C port is the ESP32-S3’s own native USB, usable as a USB host or device once your firmware sets that up.

Function	Pin	Description
TXD0	GPIO43	Serial output to PC
RXD0	GPIO44	Serial input from PC
BOOT	GPIO0	Hold low during upload if it doesn’t start automatically
EN	EN pin	Resets the chip

Conclusion

The AI-S3 gives you the ESP32-S3’s extra compute, native USB and touch/AI capabilities in a breadboard-friendly board with a built-in USB-serial adapter, no separate programmer needed. For a lower-power, cheaper RISC-V alternative from the same board family, see the AI-C3. Need something smaller instead? See the coin-sized ESP32-S3 Zero or Seeed’s XIAO ESP32S3.