Arduino UNO R3 Product Reference Manual

Description

The Arduino UNO R3 is the perfect board to get familiar with electronics and coding. This versatile microcontroller is equipped with the well-known ATmega328P and the ATMega 16U2 Processor. This board will give you a great first experience within the world of Arduino.

Target areas:

• Maker
• Introduction
• Industries

Features

ATmega328P Processor

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

Security

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

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

ATMega16U2 Processor

• 8-bit AVR® RISC-based microcontroller
• Memory: 16 KB ISP Flash, 512B EEPROM, 512B SRAM
• debugWIRE interface for on-chip debugging and programming
• Power: 2.7-5.5 volts

Ratings

2.1 Recommended Operating Conditions

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

2.2 Power Consumption

3 Functional Overview

3.1 Board Topology

Top view: The board features several key components. A USB B connector (X2) is present for power and data. A power jack (X1) is also available. The main microcontrollers are the ATmega328P Module (J-ZU4) and the ATmega16U2 Module (U3). A voltage regulator (U1) and various capacitors (PC1, PC2) and an oscillator (Y1) are also visible.

Component List:

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

The power distribution starts with VIN and USBVCC. USBVCC goes through an OPAMP. Both VIN and USBVCC supply power to a Low Dropout (LDO) regulator, providing +5V. This +5V is then used by the ATMEGA16U2-MU(R) (drawing 261mA) and the ATMEGA328P-PU (drawing 410mA). The +5V also powers the KPT-2012SGC (Green LED) which draws 5.6mA, and four KPT-2012YC (Yellow LEDs) which draw 8.7mA. Another LDO converts the +5V to +3V3.

Legend: Component (square outline), Power I/O (grey circle), Max Current (red circle), Conversion Type (green circle), Voltage Range (blue circle).

4 Board Operation

4.1 Getting Started - IDE

To program the Arduino UNO offline, install the Arduino Desktop IDE [1]. Connect the Arduino UNO to your computer using a Micro-B USB cable, which also provides power and is indicated by an LED.

4.2 Getting Started - Arduino Web Editor

All Arduino boards, including this one, work with the Arduino Web Editor [2] after installing a simple plugin. The Web Editor is hosted online, ensuring it is always up-to-date. Follow [3] to start coding and uploading sketches via the browser.

4.3 Getting Started - Arduino IoT Cloud

Arduino IoT enabled products are supported on Arduino IoT Cloud, allowing users to log, graph, and analyze sensor data, trigger events, and automate homes or businesses.

4.4 Sample Sketches

Sample sketches for the Arduino UNO can be found in the “Examples” menu of the Arduino IDE or in the "Documentation" section of the Arduino Pro website [4].

4.5 Online Resources

Explore possibilities with the board by checking projects on ProjectHub [5], the Arduino Library Reference [6], and the online store [7] for sensors and actuators.

4.6 Board Recovery

Arduino boards have a built-in bootloader for USB flashing. If a sketch locks up the processor and the board is not reachable via USB, enter bootloader mode by double-tapping the reset button immediately after power-up.

5 Connector Pinouts

The pinout diagram illustrates the connections for digital and analog pins, power, and other functionalities.

5.1 JANALOG

5.2 JDIGITAL

5.3 Mechanical Information

5.4 Board Outline & Mounting Holes

The board outline is rectangular. Dimensions are provided in mils and millimeters. The overall length is approximately 2600 mils (66.04mm) and the width is approximately 2000 mils (50.80mm). Mounting holes are located at each corner. The distance between the mounting holes on the longer sides is approximately 2600 mils (66.04mm), and on the shorter sides, it's approximately 700 mils (17.78mm) and 1800 mils (45.72mm) from the edge. There are also mounting holes near the USB connector, approximately 600 mils (15.24mm) from the edge, and a central mounting hole approximately 100 mils (2.54mm) from the edge.

6 Certifications

6.1 Declaration of Conformity CE DoC (EU)

Arduino declares that the products conform to the essential requirements of the following EU Directives, qualifying for free movement within the European Union (EU) and European Economic Area (EEA).

• ROHS 2 Directive 2011/65/EU: Conforms to EN50581:2012
• Directive 2014/35/EU (LVD): Conforms to EN 60950-1:2006/A11:2009/A1:2010/A12:2011/AC:2011
• Directive 2004/40/EC & 2008/46/EC & 2013/35/EU, EMF: Conforms to EN 62311:2008

6.2 Declaration of Conformity to EU RoHS & REACH 211 01/19/2021

Arduino boards comply with RoHS 2 Directive 2011/65/EU and RoHS 3 Directive 2015/863/EU, restricting hazardous substances in electrical and electronic equipment. The maximum permitted limits (ppm) for substances like Lead (Pb), Cadmium (Cd), Mercury (Hg), Hexavalent Chromium (Cr6+), Poly Brominated Biphenyls (PBB), Poly Brominated Diphenyl ethers (PBDE), Bis(2-Ethylhexyl} phthalate (DEHP), Benzyl butyl phthalate (BBP), Dibutyl phthalate (DBP), and Diisobutyl phthalate (DIBP) are 1000 ppm, except for Cadmium (Cd) at 100 ppm. No exemptions are claimed.

Arduino Boards also comply with European Union Regulation (EC) 1907/2006 (REACH). Arduino declares that none of the Substances of Very High Concern (SVHC) or substances on the Authorization List (Annex XIV) or Candidate List (Annex XVII) are present in significant amounts (above 0.1% concentration) in their products or packaging.

6.3 Conflict Minerals Declaration

As a global supplier, Arduino is aware of obligations regarding Conflict Minerals (Dodd-Frank Act, Section 1502). Arduino does not directly source or process these minerals. They may be present in solder or metal alloys. Arduino has contacted suppliers to verify compliance and declares that its products contain Conflict Minerals sourced from conflict-free areas.

7 FCC Caution

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.

Industry Canada Compliance: 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, and (2) this device must accept any interference, including interference that may cause undesired operation of the device.

French Compliance: 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 ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible d'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.

IC SAR Warning (French): Lors de l'installation et de l'exploitation de ce dispositif, la distance entre le radiateur et le corps est d'au moins 20 cm.

8 Company Information

Company name: Arduino S.r.l

Company Address: Via Andrea Appiani 25 20900 MONZA Italy

9 Reference Documentation

10 Revision History