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 LCD 1.3 inch Holographic Display Screen 1.3inch 3D Transparent Refractive Prism Mini TV For Arduino Raspberry Pi 5 Audio user guide Core3566102000 Industrial USB to RS485 Converter DeepSeek XiaoZhi AI Voice Chat ESP32-S3 All-in-One-PCB-Kit N16R8 WROOM-1-N16R8 DevKitC-1 Development Board Arducam Raspberry Pi 3D Display Arduino IR Thermal Imaging Camera Raspberry Pi 5 PCIe to USB3 HUB Double 2.5G ETH RJ45 and M.2 NVMe SSD PI5 Expansion board HAT+ SIM8260G M2 3G/4G/5G/GNSS/GPS Sub-6G PCIe M.2 Moudle For LTE-A/NSA/SA For DFOTA /VoLTE For SIMCOM ESP32 S3 Development Board 2.8 inch Round LCD Display 480x480 QMI8658 Sensor / SD /MP3 Audio /Battery Port LVGL/HMI For Arduino Magnetic Encoder Servo Motor 35KG.CM 24V 360&deg; RS485 High Precision And Large Torque RSBL35-24-HS Raspberry Pi MLX90641 ESP32 S3 Development Board 1.5 inch Round Rotary OLED TouchScreen Smart Knob Display 1.5inch Display 466x466 LVGL for Arduino Raspberry Pi LCD SpotPear ESP32-C3 1.47 inch LCD Display Development Board 1.47inch Screen SD 172×320 DeepSeek AI Voice Chat ESP32 Development Board 3.5 inch TouchScreen Display 320x480 Luckfox PicoKVM KVM NanoKVM RV1106 Pico Remote Control /Power /Desktop Maintenance Server HDMI USB For PiKVM Raspberry Pi

Arduino Uno R3 Hardware Reference

UNO R3 Development board Case ABS UNO R3 case for Arduino