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： ESP32-S3 1.14inch LCD ESP32 S3 5inch DeepSeek XiaoZhi AI Voice Chat Robot BOX ESP32-S3 Development Board 1.28 inch Round LCD 1.28inch TouchScreen N16R8 IPS spotpear Pi5 VGA to LVDS Raspberry Pi 10.1 inch QLED Quantum Dot Display 1280x720 Capacitive Touchscreen For Computer PC/Jetson/Game 1.54 inch Passive NFC e-Paper BW Display E-ink Screen No Need Battery Wireless Powered & Data Transfer Milk-V Duo S eMMC version firmware burning Arduino Board Managers Tutorial User Guide Raspberry Pi 5 Pure-Copper Cooler ESP32-P4 ESP32-C6 Development Board RISC-V WiFi6 MIPI CSI Camera 7/10.1 inch DSI Display /RJ45 Ethernet /Mic /Audio Size Compatible with Raspberry Pi Raspberry Pi 5 DSI ESP32-P4 Pico WIFI6 Development Board C6 MIPI DSI 10.1-inch Display /CSI Camera /Audio Speaker Mic AI Deepseek Raspberry Pi 5 Power Raspberry Pi Pico 2 RP2350A Audio Box 1.85-inch LCD Round 1.85inch TouchScreen Speaker 360x360 Raspberry Pi ST7789 RS232 to RJ45

Arduino Uno R3 Hardware Reference

UNO R3 Development board Case ABS UNO R3 case for Arduino