ESP32 C3 Zero Development Board

Code name: ESP32C3_DEV

ESP32 C3 Zero development board is based on esp32c3 microcontroller and uses riscv32 architecture. This board has a maximum CPU frequency of 160 MHz and a flash size of 4MB.

⚡ Tech Specs 📌 Pinout 🔗 Useful Links 🗺️ Mappings 🛠️ Tools

About ESP32 C3 Zero

The ESP32-C3-Zero is a compact development board featuring the Espressif ESP32-C3FN4 chip. It offers 2.4GHz Wi-Fi (802.11 b/g/n) and Bluetooth 5 (LE), making it ideal for IoT projects needing reliable wireless connectivity. 📶

Its small form factor makes it easy to integrate into space-constrained projects, and the onboard ceramic antenna ensures stable wireless performance without requiring an external antenna.

For ease of use, it includes a BOOT button and a RESET button, simplifying development and debugging. 🚀

With 15 GPIO pins and support for multiple interfaces (SPI, I2C, UART, I2S, ADC), the ESP32-C3-Zero is a flexible choice for your next embedded project! ⚙️

Where to Buy

Starting from

$4.90 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

🛰️ 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

Ultra-compact size: 23.5 × 18 mm
Low power consumption: deep sleep current ~43μA
Onboard WS2812 RGB LED (GPIO8)
15 digital IO pins
22 external interrupt pins
6 analog input pins
15 PWM pins

View Full Datasheet

ESP32 C3 Zero Pinout

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

The board features multiple communication interfaces:

UART: RX, TX
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

For general GPIO usage, these are the safest and most flexible choices:

🔹 IO0

🔹 IO1

🔹 IO3

🔹 IO10

Why Are These Pins Safe?

Not involved in bootstrapping → No impact on device boot mode or system startup
Not linked to flash memory or PSRAM → Won't interfere with storage or memory access
Not dedicated to USB or JTAG → Free for general use without affecting debugging
No special hardware connections → Freely assignable without internal conflicts

⚠️ Pins to Avoid or Use with Caution

Some pins are reserved for critical functions like bootstrapping, JTAG debugging, USB communication, and flash memory operations. Misusing these pins may lead to boot failures, programming issues, USB conflicts, or disruptions in flash storage.

Critical Pin Categories:

🛠️ Strapping Pins: Control boot behavior and flash voltage selection
🔗 JTAG Debugging Pins: Required for low-level debugging
🔌 USB Communication Pins: Used for USB Serial/JTAG communication
⚡ Flash Memory & SPI Pins: Connected to SPI flash memory and PSRAM
📡 UART Serial Communication Pins: Used for debugging and firmware uploads

PIN	Label	Reason	Function
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
IO18	USB_D-	By default connected to on-chip USB Serial/JTAG controller; to use as GPIO it must be reconfigured from its USB function	🔌 USB
IO19	USB_D+	By default connected to on-chip USB Serial/JTAG controller; not available for GPIO use unless USB functionality is disabled or remapped	🔌 USB
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

ESP32 C3 Zero Useful Links

🔗 Datasheet

https://www.waveshare.com/wiki/ESP32-C3-Zero

🔗 ESP32C3 Datasheet

https://www.espressif.com/sites/default/files/documentation/esp32-c3_datasheet_en.pdf

ESP32 C3 Zero Pin Mappings

This development board provides 15 digital IO pins, out of which 22 can be used as external interrupt pins , 6 as analog input pins and 15 pins have Pulse-Width Modulation (PWM) .

Pin	Function	ESP Pin	Input/Output	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	IO0	BIDIRECTIONAL	GPIO, ADC
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
10	IO6	IO6	BIDIRECTIONAL	GPIO
11	IO7	IO7	BIDIRECTIONAL	GPIO
12	IO8	SDA	BIDIRECTIONAL	GPIO
13	IO9	SCL	BIDIRECTIONAL	GPIO
14	IO10	RX	BIDIRECTIONAL	GPIO, LED
15	IO18	RX	BIDIRECTIONAL	USB DP
16	IO19	RX	BIDIRECTIONAL	USB DM
17	IO20	RX	BIDIRECTIONAL	GPIO, UART Receive (secondary)
18	IO21	TX	BIDIRECTIONAL	GPIO, UART Transmit

Function Pin Function

ESP Pin Pin on ESP32

I/O Input/Output Pin

Description Pin Description

ESP32 C3 Zero Pins Mapping Arduino IDE

Below you can find the ESP32 C3 Zero pinout. This development board provides 15 digital IO pins, out of which 22 can be used as external interrupt pins, 6 as analog input pins and 15 pins have Pulse-Width Modulation (PWM).

Pin	Analog	Touch	PWM	Other
0				IO0
1				IO1
2				IO2
3				IO3
4				SCK IO4
5				MISO IO5
6				MOSI IO6
7				SS IO7
8				LED_BUILTIN SDA IO8
9				SCL IO9
20				RX IO20
21				TX IO21

Analog Analog input pins

Touch Touch pins

Function Function pins

RX / TX Receive/Transmit

LED_BUILTIN Built-in LED

PWM Pulse-Width Modulation

Default Tools

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 B)
Maximum data size	320 Kb (327680 B)

The ESP32 C3 Zero development board by default uses esptool_py uploader tool, esp_ota network uploader tool for Over-the-air (OTA) uploads and esptool_py bootloader tool. The bootloader starts at address "0x0". Flash mode and boot mode for ESP32 C3 Zero development board by default is qio and qio respectively.