Arduino Uno Rev. 3

A000066 Arduino Uno Rev 3: a new and improved Duemilanove

This latest edition version of the Arduino Uno board includes the many improvements already incorporated into the Duemilanove.

Just like its big sister, it offers:

• a header extension and a RESET button to make your board easier to use with a shield;
• a 500 mA fuse to protect your computer’s USB port;
• a circuit for switching, without a jumper, from a USB supply to an external power supply;/li>
• low energy consumption.

Like all Arduino Arduino boards, it is also inexpensive and gives you access to an entire open source Arduino-specific programming system.

Need help choosing the right Arduino? Check out our guide!

New features of the Arduino Uno Rev. 3

In addition to continuing all the advantages of the Duemilanove, the Arduino Uno Rev. 3 has a number of new features, particularly in terms of its USB interfacing hardware. You also have an Arduino pinout extension for your I2C pins and an IOREF pin for adapting your shield to the board regardless of its voltage (3.3 or 5V).

A second, unconnected pin is also available next to the IOREF pin in anticipation of subsequent uses.

Also note that the A000066 Arduino Uno Rev. 3 board is backward-compatible with the hardware used on Duemilanove and earlier versions of the Arduino Uno.

Finally, this board’s designers have replaced the ATmega8U2 with a more powerful ATmega16U2 chip.

Technical specifications of the A000066 Arduino Uno Rev. 3

• Microcontroller: ATmega328
• Operating voltage: 5V
• Recommended supply voltage: 7–12V
• Supply voltage (limits): 6–20V
• Digital I/O pins: 14 (including 6 providing PWM output)
• Analogue input pins: 6
• Direct current per I/O pin: 40 mA
• Direct current (3.3V pin): 50 mA
• Flash memory: 32 kB
• SRAM: 2 kB
• EEPROM: 1 kB
• Frequency: 16 MHz

Resources for the Arduino UNO R3 A000066

The open-source IDE can be downloaded for free (currently for Mac OS X, Windows, and Linux). Some tutorials are available on the official Arduino web site. These tutorials help you to write your first program with Arduino boards.

Eagle Files - Reference Design for Arduino Uno Rev3 

Datasheet ATmega238P for Arduino Uno Rev3