1

ARDUINO UNO
The Arduino Uno R3 is a popular Microcontroller Board designed
for beginners and hobbyists to easily create interactive
electronic projects. It's part of the Arduino family of boards, which
are open-source hardware platforms that provide a simple and
accessible way to develop various electronic projects, from
simple blinking LEDs to more complex Automation Systems.

BUY ARDUINO
UNO R3 NOW
2

FEATURES
1) ATMega328P Processor

2) Memory
• AVR CPU at up to 16 MHz
• 32KB Flash
• 2KB SRAM
• 1KB EEPROM

3) Security
• Power On Reset (POR)
• Brown Out Detection (BOD)

4) Peripherals
• 2x 8-bit Timer/Counter with a dedicated period register and compare channels
• 1x 16-bit Timer/Counter with a dedicated period register, input capture and
compare channels
• 1x USART with fractional baud rate generator and start-of-frame detection
• 1x controller/peripheral Serial Peripheral Interface (SPI)
• 1x Dual mode controller/peripheral I2C
• 1x Analog Comparator (AC) with a scalable reference input
• Watchdog Timer with separate on-chip oscillator
• Six PWM channels
• Interrupt and wake-up on pin change

5) ATMega16U2 Processor
• 8-bit AVR® RISC-based microcontroller

6) Memory
• 16 KB ISP Flash
• 512B EEPROM
• 512B SRAM
• debugWIRE interface for on-chip debugging and programming

7) Power
• 2.7-5.5 volts
3

CONTENTS
1) The Board
1.1 Application Examples
1.2 Related Products

2) Ratings
2.1 Recommended Operating Conditions
2.2 Power Consumption

3) Functional Overview
3.1 Board Topology
3.2 Processor
3.3 Power Tree

4) Board Operation
4.1 Getting Started - IDE
4.2 Getting Started - Arduino Web Editor
4.3 Getting Started - Arduino IoT Cloud
4.4 Sample Sketches
4.5 Online Resources

5) Connector Pinouts
5.1 JANALOG
5.2 JDIGITAL
5.3 Mechanical Information
5.4 Board Outline & Mounting Holes

6) Certifications
6.1 Declaration of Conformity CE DoC (EU)
6.2 Declaration of Conformity to EU RoHS & REACH 211 01/19/2021
6.3 Conflict Minerals Declaration

7) FCC Caution

8) Company Information

9) Reference Documentation

10) Revision History

4

1) The Board
1.1 Application Examples
The UNO board is the flagship product of Arduino. Regardless if you are new to the world of
electronics or will use the UNO as a tool for education purposes or industry-related tasks.

First entry to electronics: If this is your first project within coding and electronics, get started with our
most used and documented board; Arduino UNO. It is equipped with the well-known ATmega328P
processor, 14 digital input/output pins, 6 analog inputs, USB connections, an ICSP header, and a
reset button. This board includes everything you will need for a great first experience with Arduino.

Industry-standard development board: Using the Arduino UNO board in industries, there are a
range of companies using the UNO board as the brain for their PLCs.

Education purposes: Although the UNO board has been with us for about ten years, it is still widely
used for various education purposes and scientific projects. The board's high standard and top-
quality performance make it a great resource for capturing real-time from sensors and triggering
complex laboratory equipment to mention a few examples.

1.2 Related Products

• Starter Kit
• Tinkerkit Braccio Robot
• Example

2) Ratings
2.1 Recommend Operating Condition

NOTE:
In extreme temperatures, EEPROM, voltage regulator, and the crystal oscillator, might not
work as expected due to the extreme temperature conditions
5

2.2 Power Consumption

3) Functional Overview
3.1 Board Topology
6

3.2 Processor
The Main Processor is an ATmega328P running at up to 20 MHz. Most of its pins are connected to the
external headers, however, some are reserved for internal communication with the USB Bridge
coprocessor.

3.3 Power Tree

7

4) Board Operation
4.1 Getting Started- IDE
If you want to program your Arduino UNO while offline you need to install the Arduino Desktop IDE.
To connect the Arduino UNO to your computer, you’ll need a Micro-B USB cable. This also provides
power to the board, as indicated by the LED.

4.2 Getting Started- Arduino Web Editor

All Arduino boards, including this one, work out-of-the-box on the Arduino Web Editor, by just
installing a simple
plugin.

The Arduino Web Editor is hosted online, therefore it will always be up-to-date with the latest
features and support for all boards. Follow to start coding on the browser and upload your sketches
onto your board.

4.3 Getting Started- Arduino IoT Cloud

All Arduino IoT-enabled products are supported on Arduino IoT Cloud which allows you to Log,
graph, and analyze sensor data, trigger events, and automate your home or business.

4.4 Sample Sketches

Sample sketches for the Arduino XXX can be found either in the “Examples” menu in the Arduino IDE
or in the “Documentation” section of the Arduino Pro website.

4.5 Online Resources

Now that you have gone through the basics of what you can do with the board you can explore the
endless possibilities it provides by checking exciting projects on ProjectHub, the Arduino Library
Reference, and the online store where you will be able to complement your board with sensors,
actuators and more.
8

5) Connector Pinouts
9

5.1 Janalog

5.2 JDigital
10

5.3 Mechanical Information

5.4 Board Outline and Mounting Holes

11

6) Certifications
6.1 Declaration of Conformity CE DoC EU
We declare under our sole responsibility that the products above conform with the essential
requirements of the following EU Directives and therefore qualify for free movement within markets
comprising the European Union (EU) and European Economic Area (EEA).

6.2 Declaration of Conformity to EU RoHS & REACH 211 1/19/2021

Arduino boards are in compliance with RoHS 2 Directive 2011/65/EU of the European Parliament and
RoHS 3 Directive 2015/863/EU of the Council of 4 June 2015 on the restriction of the use of certain
hazardous substances in electrical and electronic equipment.

Arduino Boards are fully compliant with the related requirements of European Union Regulation (EC)
1907 /2006 concerning the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH).
We declare none of the SVHCs (https://echa.europa.eu/web/guest/candidate-list-table), the
Candidate List of Substances of Very High Concern for authorization currently released by ECHA, is
present in all products (and also package) in quantities totaling in a concentration equal or above 0.1%.
To the best of our knowledge, we also declare that our products do not contain any of the substances
listed on the "Authorization List" (Annex XIV of the REACH regulations) and Substances of Very High
Concern (SVHC) in any significant amounts as specified by the Annex XVII of Candidate list published
by ECHA (European Chemical Agency) 1907 /2006/EC.
12

6.3 Conflict Minerals Declaration

As a global electrical components, Arduino is aware of our obligations to laws and regulations
regarding Conflict Minerals, specifically the Dodd-Frank Wall Street Reform and Consumer
Protection Act, Section 1502. Arduino does not directly source or process conflict minerals such as
Tin, Tantalum, Tungsten, or Gold. Conflict minerals are contained in our products in the form of
solder or as a component in metal alloys. As part of our reasonable due diligence, Arduino has
contacted component suppliers within our supply chain to verify their continued compliance with
the regulations. Based on the information received thus far we declare that our products contain
Conflict Minerals sourced from conflict-free areas.

7) FCC Caution
Any Changes or modifications not expressly approved by the party responsible for compliance
could void the user’s authority to operate the equipment.
This device complies with part 15 of the FCC Rules. Operation is subject to the following two
conditions:
(1) This device may not cause harmful interference
(2) this device must accept any interference received, including interference that may cause
undesired operation.

FCC RF Radiation Exposure Statement:

1. This Transmitter must not be co-located or operating in conjunction with any other antenna or
transmitter.
2. This equipment complies with RF radiation exposure limits set forth for an uncontrolled
environment.
3. This equipment should be installed and operated with minimum distance 20cm between the
radiator & your body.

English: User manuals for license-exempt radio apparatus shall contain the following or equivalent
notice in a conspicuous location in the user manual or alternatively on the device or both. This
device complies with Industry canada license-exempt RSS standard(s). Operation is subject to the
following two conditions:
(1) this device may not cause interference
(2) this device must accept any interference, including interference that may cause undesired
operation of the device.

French: Le présent appareil est conforme aux CNR d’Industrie Canada applicables aux appareils
radio exempts de licence. L’exploitation est autorisée aux deux conditions suivantes :
(1) l’ appareil nedoit pas produire de brouillage
(2) l’utilisateur de l’appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage
est susceptibled’en compromettre le fonctionnement.

IC SAR Warning:
English This equipment should be installed and operated with minimum distance 20 cm between
the radiator and your body.

French: Lors de l’ installation et de l’ exploitation de ce dispositif, la distance entre le radiateur et le

corps est d ’aumoins 20 cm.