ESP32-S3-Zero Mini Development Board

Introduction

The ESP32-S3-Zero are ultra-compact boards with castellated holes, designed for seamless integration into other host circuits. The ESP32-S3-Zero is equipped with a Type-C USB connector, providing access to most of the unutilized pins while maintaining a small footprint. It features the ESP32-FH4R2 SoC, which supports low-power Wi-Fi and Bluetooth 5.0, along with 4MB Flash and 2MB PSRAM. The module is also integrated with hardware-based encryption accelerators, RNG, HMAC, and Digital Signature modules, catering to the security requirements of IoT applications. With its low-power mode, the board is ideal for use in a variety of scenarios, including IoT devices, mobile gadgets, wearable technology, and smart home solutions.

Specifications

Specification	Details
Processor	Xtensa® 32-bit LX7 dual-core, up to 240MHz
Wi-Fi & Bluetooth	2.4GHz Wi-Fi (802.11 b/g/n), Bluetooth® 5 (LE)
Memory	512KB SRAM, 384KB ROM, 4MB Flash, 2MB PSRAM
Module Features	Castellated module with onboard ceramic antenna, direct soldering
Power Efficiency	Flexible clock and independent power supply settings
USB Controller	Full-speed USB serial port controller
GPIO Pins	24 configurable GPIO pins
Interfaces	4 × SPI, 2 × I2C, 3 × UART, 2 × I2S, 2 × ADC, etc.

Features

Equipped with Xtensa® 32-bit LX7 dual-core processor, operating at a maximum frequency of 240MHz.
Supports 2.4GHz Wi-Fi (802.11 b/g/n) and Bluetooth® 5 (LE).
Includes 512KB of SRAM, 384KB of ROM, 4MB of onboard Flash memory, and 2MB of PSRAM.
Features a castellated module with an integrated ceramic antenna, enabling direct soldering to carrier boards.
Supports flexible clock settings, independent power supply options for the module, and other controls to optimize power efficiency in various use cases.
Comes with a full-speed USB serial port controller.
Provides 24 GPIO pins offering versatile pin assignments.
Offers 4 SPI, 2 I2C, 3 UART, 2 I2S, and 2 ADC interfaces, among others.

Hardware overview

ESP32-S3-Zero Pinout (Short Description):

Power Pins: 5V, GND, 3V3 for powering the board.
Communication: Supports UART (TX/RX), I2C, SPI, and I2S.
GPIOs: Configurable as PWM, ADC, UART, or digital I/O.
Special Pins: GPIO8–15 for SPI/UART; GPIO17 as general-purpose.
Programming: C-Type USB interface for uploading code and debugging.

⚠️ Strapping / boot-sensitive pins (use with care)

These pins are sampled at reset.
They are usable after boot, but must not be strongly driven during reset.

⚠️ Use carefully:

Rules:

No strong pull-ups / pull-downs (<10k)
No devices driving them at boot
GPIO46 is input-only

⚠️ USB-related pins (special behavior)

ESP32-S3 has native USB, usually wired internally on Zero/Mini boards.

⚠️ Usually tied to USB:

Often not broken out
If broken out, do not use unless you disable USB completely