ESP32-S3-Zero

Development Board

Code name: ESP32S3_DEV

ESP32-S3-Zero is a development board based on the ESP32S3 microcontroller using XTENSA architecture.

This board features a maximum CPU frequency of 240 MHz and 4MB flash memory.

About ESP32-S3-Zero

The ESP32-S3-Zero is a compact development board featuring the Espressif ESP32-S3FH4R2 dual-core processor, operating at up to 240MHz. It offers 2.4GHz Wi-Fi (802.11 b/g/n) and Bluetooth 5 (LE) capabilities, making it ideal for IoT projects requiring robust wireless connectivity. 📶

With its small form factor of 23.5 × 18 mm, the board is designed for easy integration into space-constrained applications. The onboard ceramic antenna ensures stable wireless performance without the need for an external antenna.

For user convenience, the ESP32-S3-Zero includes both a BOOT button and a RESET button, facilitating straightforward development and debugging processes. 🚀

Equipped with 24 multifunctional GPIO pins, the board supports various interfaces, including:

4 × SPI
2 × I2C
3 × UART
2 × I2S
2 × ADC

Where to Buy ESP32-S3-Zero

Starting from

$6.27 per unit

Amazon.com Ships worldwide

View Price

Amazon.de Ships to EU

View Price

AliExpress Best value

View Price

Prices are subject to change. We earn from qualifying purchases as an Amazon Associate.

Technical Specifications

Complete technical specification details for ESP32-S3-Zero

Connectivity

WiFi 802.11 b/g/n (2.4 GHz)

Bluetooth 5.0

BLE 5.0

Microcontroller

Model esp32s3

Clock Speed 240 MHz

Flash Size 4MB

Architecture xtensa

✨ Features & Pins

Digital IO 24

Analog Input 2

PWM 24

Interrupts 24

• Ultra-compact size: 23.5 × 18 mm
• Low power consumption: supports various power modes for energy-efficient applications
• Onboard WS2812 RGB LED connected to GPIO21

Download Full Datasheet

Quick Setup

Copy-paste configs for ESP32-S3-Zero - auto‑generated from this board's exact hardware specs.

ESP32S3 240 MHz 4MB QIO Xtensa

In Arduino IDE 2 select Esp32s3 Dev from the esp32 by Espressif package. In PlatformIO use board = esp32-s3-devkitm-1. ESP32S3 · 240 MHz · 4MB · QIO.

Tools menu settings

Board (select in Arduino IDE) Esp32s3 Dev

CPU Frequency 240 MHz

Flash Size 4MB

Flash Mode QIO

Upload Speed 921600

Architecture Xtensa

In Arduino IDE 2, open Boards Manager, search "esp32" by Espressif and install it. Then go to Tools → Board and select "Esp32s3 Dev" for the ESP32-S3-Zero.

platformio.ini


[env:esp32-s3-zero]
platform  = espressif32
board     = esp32-s3-devkitm-1
framework = arduino

; Exact hardware config for ESP32-S3-Zero
board_build.mcu        = esp32s3
board_build.f_cpu      = 240000000L
board_build.flash_size = 4MB
board_build.flash_mode = qio
board_upload.flash_size = 4MB

The board value is a close generic match - check PlatformIO board registry for an exact fit.

esp32: block (YAML)


esp32:
  board: esp32-s3-devkitc-1
  framework:
    type: arduino   # or "esp-idf"

# ESP32-S3-Zero - 240 MHz ESP32S3
# Flash: 4MB | USB: N/A

Paste into your device's .yaml. See ESPHome ESP32 docs for full options.

esptool.py - flash command


esptool.py \
  --chip esp32s3 \
  --baud 921600 \
  write_flash \
    --flash_mode qio \
    --flash_size 4MB \
    0x0 bootloader.bin \
    0x8000    partitions.bin \
    0xe000    boot_app0.bin \
    0x10000   firmware.bin

Install: pip install esptool - replace firmware.bin with your binary - bootloader at 0x0

ESP32-S3-Zero Board Dimensions

Physical measurements for ESP32-S3-Zero

ESP32-S3-Zero dimensions - height, width

Width 18.00mm

Length 23.50mm

Pin Gap 2.54mm

ESP32-S3-Zero Pinout Diagram

Complete pin reference for ESP32-S3-Zero

The ESP32-S3-Zero pinout is engineered for versatility within a compact footprint. Key power pins include 5V, 3.3V, and GND, ensuring reliable power delivery for various peripherals.

The board offers multiple communication interfaces:

UART: TX (GPIO43), RX (GPIO44)
I2C: SDA, SCL
SPI: SCK, MISO, MOSI, SS

For analog input, it provides ADC pins suitable for reading sensor data or voltage levels.

Safe Pins to Use

These pins are safe for general GPIO usage without boot or system conflicts

IO1

IO2

IO4

IO5

IO6

IO7

IO8

IO15

IO16

IO17

IO18

Why Are These Pins Safe?

✓ No boot sequence involvement

✓ No flash/PSRAM connections

✓ No USB or JTAG conflicts

✓ Freely assignable without issues

Pins to Avoid or Use with Caution

Reserved for critical functions. Misuse may cause boot failures, programming issues, or system conflicts.

Strapping Pins

Boot behavior & flash voltage

JTAG Debugging

Low-level debugging interface

USB Pins

USB Serial/JTAG communication

Flash/SPI Pins

Memory & PSRAM connections

UART Serial

Debugging & firmware uploads

PIN	Label	Why Avoid	Type
IO3	GPIO3	Sampled at reset to select JTAG interface (USB Serial/JTAG controller vs. external pins). Improper use can disable external JTAG or alter debug interface.	🛠️ Strapping
IO9	FSPIHD	Connected to external flash (data/hold signal) on most modules. Not recommended for use as GPIO, since it must remain dedicated to flash communication.	⚡ Flash
IO10	FSPICS0	Used to select the external flash chip. It is required for flash access and cannot be repurposed without losing flash connectivity	⚡ Flash
IO11	FSPID	Used as a data line for flash (and in-package PSRAM). It should not be used as GPIO when the flash/PSRAM is in use.	⚡ Flash
IO12	FSPICLK	Drives the flash (and PSRAM) clock. This critical signal must be reserved for memory and not used as general GPIO.	⚡ Flash
IO13	FSPIQ	Used as a data line for flash/PSRAM transfers. Not available for other uses when flash/PSRAM is connected.	⚡ Flash
IO14	FSPIWP	Connected to external flash (data/write-protect signal). Not recommended as GPIO because it’s reserved for flash operations.	⚡ Flash
IO38	FSPIWP	On flash-equipped chips, this pin is tied to the flash’s WP# (or D3) line. It should be avoided for other use, as it’s needed for flash operations.	⚡ Flash
IO39	MTCK (GPIO39)	Default JTAG debugging TCK pin. If JTAG is needed, this pin must be free; it may also be used internally for PSRAM chip select on certain modules, so avoid repurposing it.	🪛 Other
IO40	MTDO (GPIO40)	Default JTAG TDO output for debugging. Using it as GPIO will interfere with JTAG debugging functionality.	🪛 Other
IO41	MTDI (GPIO41)	Default JTAG TDI input for debugging. Should be reserved for JTAG or left unused if JTAG is to remain available.	🪛 Other
IO42	MTMS (GPIO42)	Default JTAG TMS signal for debugging. Using this pin for other purposes will disable the JTAG interface (unless JTAG is rerouted to USB).	🪛 Other
IO45	GPIO45	Determines flash/PSRAM power voltage (3.3 V vs 1.8 V) at boot. Must match hardware configuration; using as GPIO can upset flash supply setting.	🛠️ Strapping

Useful Links

Datasheets and resources for ESP32-S3-Zero

Board Datasheet

Technical specifications

ESP32S3 Datasheet

Microcontroller reference

ESP32-S3-Zero Custom Pin Mapping

Pin configuration and GPIO mapping for ESP32-S3-Zero

Digital I/O Pins

Interrupt Pins

Analog Inputs

PWM Pins

Pin	Function	ESP Pin	I/O Type	Description
1	5V	5V	POWER INPUT	5V power input for the board
2	GND	GND	POWER GROUND	Ground connection
3	3V3	3.3V	POWER OUTPUT	3.3V power output
5	IO1	IO1	BIDIRECTIONAL	GPIO, ADC
6	IO2	IO2	BIDIRECTIONAL	GPIO, ADC
7	IO3	IO3	BIDIRECTIONAL	GPIO, ADC
8	IO4	IO4	BIDIRECTIONAL	GPIO, ADC
9	IO5	IO5	BIDIRECTIONAL	GPIO, ADC
10	IO6	IO6	BIDIRECTIONAL	GPIO, ADC
11	IO7	IO7	BIDIRECTIONAL	GPIO, ADC
12	IO8	IO8	BIDIRECTIONAL	GPIO, ADC
13	IO9	IO9	BIDIRECTIONAL	GPIO, ADC
14	IO10	IO10	BIDIRECTIONAL	GPIO, ADC
15	IO11	IO10	BIDIRECTIONAL	GPIO, ADC
16	IO12	IO10	BIDIRECTIONAL	GPIO, ADC
17	IO13	IO10	BIDIRECTIONAL	GPIO, ADC
18	IO14	IO10	BIDIRECTIONAL	GPIO, ADC
19	IO15	IO10	BIDIRECTIONAL	GPIO, ADC
20	IO16	IO10	BIDIRECTIONAL	GPIO, ADC
21	IO17	IO10	BIDIRECTIONAL	GPIO, ADC
22	IO18	IO10	BIDIRECTIONAL	GPIO, ADC
23	IO38	IO10	BIDIRECTIONAL	GPIO
24	IO39	IO10	BIDIRECTIONAL	GPIO
25	IO40	IO10	BIDIRECTIONAL	GPIO
26	IO41	IO10	BIDIRECTIONAL	GPIO
27	IO42	IO10	BIDIRECTIONAL	GPIO
28	IO45	IO10	BIDIRECTIONAL	GPIO

Legend

Function Pin role

GPIO ESP32 pin

I/O Direction

# Pin number

Default Tools & Configuration

Build and upload settings for ESP32-S3-Zero

Setting	Value
Bootloader tool	esptool_py
Uploader tool	esptool_py
Network uploader tool	esp_ota
Bootloader address	`0x0`
Flash mode	qio
Boot mode	qio
Maximum upload size	4096 KB (4194304 bytes)
Maximum data size	512 KB (524288 bytes)