This document provides information about the pins and functions of an Arduino Uno board. It includes a pinout diagram labeling the physical pin connections and their associated functions. Key aspects highlighted are the ATmega328 microcontroller, analog and digital pin mappings, power specifications noting a maximum of 150mA per source and 200mA total, and serial port connections for programming and communication.

1. LEGEND
RESET PCINT5 PC6 1 28 PC5 PCINT13 ADC5 A5 SCL
GND
0 RXD PCINT16 PD0 2 27 PC4 PCINT12 ADC4 A4 SDA
POWER
CONTROL 1 TXD PCINT17 PD1 3 26 PC3 PCINT11 ADC3 A3
PHYSICAL PIN 2 INT0 PCINT18 PD2 4 25 PC2 PCINT10 ADC2 A2
PORT PIN OC2B PWM 3 INT1 PCINT19 PD3 5 24 PC1 PCINT9 ADC1 A1
ATMEGA328
ATMEGA328 PIN FUNC T0 4 XCK PCINT20 PD4 6 23 PC0 PCINT8 ADC0 A0
DIGITAL PIN VCC 7 22 GND
ANALOG-RELATED PIN GND 8 21 AREF
PWM PIN OSC1 XTAL1 PCINT6 PB6 9 20 VCC
SERIAL PIN
OSC2 XTAL2 PCINT7 PB7 10 19 PB5 PCINT5 SCK 13
ARDUINO PIN
OC0B PWM 5 T1 PCINT21 PD5 11 18 PB4 PCINT4 MISO 12
Source Total 150mA
OC0A PWM 6 AIN0 PCINT22 PD6 12 17 PB3 PCINT3 OC2A 11 PWM MOSI
Source Total 150mA
7 AIN1 PCINT23 PD7 13 16 PB2 PCINT2 OC1B 10 PWM SS
General Information
ICP1 8 CLKO PCINT0 PB0 14 15 PB1 PCINT1 OC1A 9 PWM
Pay Attention
No Really
PAY ATTENTION
LED
USB
POWER JACK www.pighixxx.com
BARREL
JACK BY PIGHIXXX
Absolute max per pin 40mA 29 JAN 2013
THE reccomended 20mA
UNOFFICIAL Absolute max 200mA SCL
R3 Only
for entire package SDA
ARDUINO Reserved
AREF AREF
UNO
GND GND
13 19 PB5 PCINT5 SCK
R3 Only IOREF IOREF 12 18 PB4 PCINT4 MISO
RESET RESET 11 17 PB3 OC2A PCINT3 PWM MOSI
PINOUT DIAGRAM 3V3 3,3V 10 16 PB2 OC1B PCINT2 PWM SS
ATMEGA328
5V 5V 9 15 PB1 OC1A PCINT1 PWM
GND GND 8 14 PB0 CLKO PCINT0 ICP1
GND GND
Vin Vin 7 13 PD7 AIN1 PCINT23 Sink Total 100mA
6 12 PD6 AIN0 PCINT22 PWM OC0A
PCINT8 ADC0 PC0 23 A0 5 11 PD5 T1 PCINT21 PWM
PCINT9 ADC1 PC1 24 A1 4 6 PD4 T0 PCINT20 XCK
RESET
PCINT10 ADC2 PC2 25 A2 3 5 PD3 INT1 PCINT19 PWM OC2B
Sink Total 100mA SCK
PCINT11 ADC3 PC3 26 A3 2 4 PD2 INT0 PCINT18 Sink Total 100mA
MISO
SDA PCINT12 ADC4 PC4 27 A4 TX 1 3 PD1 TXD PCINT17 TX Connected to the ATMega
and used for USB program
SCL PCINT13 ADC5 PC5 28 A5 RX 0 2 PD0 RXD PCINT16 RX and communicating with it
ICSP
5V
MOSI
GND