Interactive Board Pinout
Arduino UNO R3
Pinout for the classic ATmega328P board. Click any exposed header pin to inspect alternate functions, electrical behavior, and practical wiring notes without leaving the page.
ATmega328P
Microcontroller
5V
Logic level
16 MHz
Clock
14 pins
Digital I/O
6 channels
Analog inputs
6 pins
PWM outputs
I2C / REFERENCE
DIGITAL I/O
POWER
ANALOG IN
USB-B
DC IN
ATmega328P
ATmega16U2
ICSP
L
16 MHz
USB UART
UNO R3