Arduino Uno R3 Hardware Reference

In the Arduino development board family, the Uno development board is the most beginner-friendly Arduino development board. Because it is easy to learn, stable and reliable, the Uno development board is also the most widely used development board with the most reference materials.

Arduino Uno is a development board based on microcontroller ATmega328P. It has 14 digital input/output pins (6 of these pins can be used as PWM output pins), 6 analog input pins, 16 MHz quartz crystal oscillator, USB interface, power interface, supports in-circuit serial Programming and reset buttons. Users only need to connect the development board to the computer through the USB interface to use it.

If you choose the Arduino clone board, you can learn how to install the driver for the Arduino clone board through our tutorial.

The main technical parameters

Microcontroller: ATmega328P

Working voltage: 5 volts

Input voltage (recommended) : 7-12 volts

Input voltage (limit) : 6-20 volts

Digital input and output pins: 14 (6 of which can be used as PWM pins)

PWM pins: 6

Analog input pins: 6

Input/Output Pin DC Current : 20mA

3.3V pin current: 50 mA

Flash Memory (flash memory): 32 KB (ATmega328P) of which 0.5 KB is used for system boot (bootloader)

SRAM (static memory): 2 KB (ATmega328P)

EEPROM: 1KB (ATmega328P)

Built-in LED pins: 13

Length: 68.6mm

Width: 53.4mm

Weight : 25g

Clock frequency: 16MHz

Pin Description Diagram

TAG： Raspberry Pi Transparent LCD Raspberry Pi Pico 2 RP2350 2 inch LCD Capacitive TouchScreen Development Board 240x320 Display QMI8658 6-Axis /OV5640 Camera /SD /Battery Port Raspberry Pi DSI display ESP32 C6 AI 0.85inch Development Board 0.85 inch DeepSeek RGB surround light Dual mike Industrial-grade isolated 2-way RS485 hub repeater One RS485 TO Two RS485 Raspberry Pi 5 1.3inch LCD and Audio Speaker Raspberry Pi Zero 4G Cat1 With USB Hub Expansion Board LTE/GPS/EA/EU also For Zero 2W Raspberry Pi LCD 3D Display Raspberry Pi CM5 Gigabit/2.5G Dual Ethernet Expansion Board with RJ45 GPIO IO Base Raspberry Pi Pico 2 RP2350 CAN Onboard XL2515 CAN Controller RP2350A Milk-V Duo User Guide SK18 Computer AI Deepseek Voice Keyboard Linux 18x1.58inch LCD Screen Customize keys ESP32 S3 Development Board 2.8 inch Round LCD Display 480x480 QMI8658 Sensor / MIC / SD /MP3 Audio /Battery Port LVGL/HMI For Arduino Metal Case Retail electronic Tag Raspberry Pi 5 PCIe TO Gigabit ETH USB3.2 HAT+ USB HUB Laser 450nm 5W high precision module Adjustable focal length For Laser Carving / Laser 3D Printing Raspberry Pi SIM7670G LTE-4G-Cat-1/GNSS/USB-HUB Expansion Board

Arduino Uno R3 Hardware Reference

UNO R3 Development board Case ABS UNO R3 case for Arduino