ESP32-C3-Zero Pro

Development Board

Code name: ESP32C3_DEV

ESP32-C3-Zero Pro is a development board based on the ESP32C3 microcontroller using RISCV32 architecture.

This board features a maximum CPU frequency of 160 MHz and 4MB flash memory.

About ESP32-C3-Zero Pro

ESP32-C3-Zero Pro is an upgraded version of the ESP32-C3-Zero, featuring a better ceramic antenna and an IPEX antenna mount for improved wireless performance. It is based on the Espressif ESP32-C3 Wi-Fi/Bluetooth dual-mode chip, with a 32-bit RISC-V single-core processor running at up to 160 MHz. It comes with 400 KB SRAM, 384 KB ROM, and 4 MB of onboard flash memory.

This board supports 2.4 GHz Wi-Fi (802.11 b/g/n) and Bluetooth 5 (LE), making it ideal for low-power IoT applications and wireless wearable devices. 📶

Compared to the ESP32-C3-Zero, the Zero Pro offers enhanced signal strength due to its dual-antenna design, making it more reliable for applications requiring strong wireless connectivity. It retains the same ultra-compact footprint (22.52 × 18 mm) while adding more connectivity options.

For user convenience, it includes both a RESET button and a BOOT button to facilitate development and debugging. 🚀

The board provides 11 digital I/O pins configurable as PWM outputs and 4 analog I/O pins for ADC inputs. It supports multiple serial interfaces, including 1× I2C, 1× SPI, and 2× UART, ensuring compatibility with a wide range of peripherals. ⚙️

Where to Buy ESP32-C3-Zero Pro

Starting from

$3 per unit

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📋 Technical Specifications

Complete technical specification details for ESP32-C3-Zero Pro

🛰️ Connectivity

WiFi 802.11 b/g/n (2.4 GHz)

Bluetooth 5.0

BLE 5.0

🧠 Microcontroller

Model esp32c3

Clock Speed 160 MHz

Flash Size 4MB

Architecture riscv32

✨ Features & Pins

Digital IO 11

Analog Input 4

PWM 11

Interrupts 22

• Improved wireless performance: Better ceramic antenna + IPEX antenna mount
• Ultra-small size: 22.52 × 18 mm
• Ultra-low power consumption: deep sleep current approximately 43 μA
• Onboard blue LED connected to GPIO8

Download Full Datasheet

ESP32-C3-Zero Pro Pinout Diagram

Complete pin reference for ESP32-C3-Zero Pro

The ESP32-C3-Zero Pro pinout is designed for versatility in a compact form factor. Key power pins include 5V, 3.3V, and GND, ensuring stable power delivery for various peripherals.

The board provides multiple communication interfaces:

UART: TX, RX
I2C: SDA, SCL
SPI: SCK, MISO, MOSI, SS

For analog input, it offers 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

IO0

IO1

IO3

IO10

💡 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
IO2	GPIO2	Must be held high during boot (if low on reset, normal flash boot may fail)	🛠️ Strapping
IO4	MTMS	Used during boot; JTAG TMS for debugging; acts as Quad-SPI flash IO (hold data line) in internal-flash variants	🔗 JTAG
IO5	MTDI	Used during boot; JTAG TDI for debugging; acts as Quad-SPI flash IO (write-protect data line) in internal-flash variants	🔗 JTAG
IO6	MTCK	Used during boot; JTAG TCK for debugging; provides flash clock in internal-flash variants	🔗 JTAG
IO7	MTDO	Used during boot; JTAG TDO for debugging; acts as Quad-SPI flash IO (data line) in internal-flash variants	🔗 JTAG
IO8	GPIO8	Must be held high during reset (if low, UART flashing/boot may not work)	🛠️ Strapping
IO9	GPIO9	Controls boot mode on reset (HIGH for normal flash boot, LOW enters serial download mode)	🛠️ Strapping
IO20	U0RXD	Used as UART0 receive (console/bootloader); repurposing may disable serial programming and debug logs	📡 UART
IO21	U0TXD	Used as UART0 transmit (console/bootloader); repurposing may disable serial console output and printing	📡 UART

Useful Links

Datasheets and resources for ESP32-C3-Zero Pro

Board Datasheet

Technical specifications

ESP32C3 Datasheet

Microcontroller reference

ESP32-C3-Zero Pro Custom Pin Mapping

Pin configuration and GPIO mapping for ESP32-C3-Zero Pro

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
4	IO0	GPIO0	BIDIRECTIONAL	GPIO, ADC, PWM
5	IO1	GPIO1	BIDIRECTIONAL	GPIO, ADC, PWM
6	IO2	GPIO2	BIDIRECTIONAL	GPIO, ADC, PWM
7	IO3	GPIO3	BIDIRECTIONAL	GPIO, ADC, PWM
8	IO4	GPIO4	BIDIRECTIONAL	GPIO, ADC, SPI SCK, PWM
9	IO5	GPIO5	BIDIRECTIONAL	GPIO, ADC, SPI MISO, PWM
10	IO6	GPIO6	BIDIRECTIONAL	GPIO, SPI MOSI, PWM
11	IO7	GPIO7	BIDIRECTIONAL	GPIO, SPI SS, PWM
12	IO8	GPIO8	BIDIRECTIONAL	GPIO, I2C Data line, PWM
13	IO9	GPIO9	BIDIRECTIONAL	GPIO, I2C Clock line, PWM
14	IO10	GPIO10	BIDIRECTIONAL	GPIO
15	IO20	TX	BIDIRECTIONAL	GPIO, UART Transmit
16	IO21	TX	BIDIRECTIONAL	GPIO, UART Transmit

Legend

Function Pin role

GPIO ESP32 pin

I/O Direction

# Pin number

Default Tools & Configuration

Build and upload settings for ESP32-C3-Zero Pro

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	1280 KB (1310720 bytes)
Maximum data size	320 KB (327680 bytes)