Arduino Uno R3 (Revision 3) Microcontroller Board - A000066

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  • Arduino Uno R3 (Revision 3) Microcontroller Board - A000066
  • Arduino Uno R3 (Revision 3) Microcontroller Board - A000066


Arduino Uno R3 (Revision 3) Microcontroller Board - A000066

The Arduino Uno R3 is a microcontroller board based on the ATmega328. It has 14 digital input/output pins (of which 6 can be used as Pulse Width Modulation (PWM) outputs), 6 analog inputs, a 16 MHz crystal oscillator, a USB connection, a DC power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with an AC-to-DC adapter or battery to get started.

We stock a wide range of plug-in accessory boards (shields), to enable most circuits to be built within minutes.
The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega16U2 which is configured as a USB-to-serial converter.
Revision 2 of the Uno board has a resistor pulling the 8U2 HWB line to ground, making it easier to put into Device Firmware Update (DFU) mode.

Revision 3 of the board has the following new features:

  • 1.0 pinout: added SDA and SCL pins that are near to the AREF pin and two other new pins placed near to the RESET pin, the IOREF that allow the shields to adapt to the voltage provided from the board. Shields will be compatible both with the board that uses the AVR, which operate with 5V, and with the Arduino Due which operates with 3.3V. The second one is a not connected pin, that is reserved for future purposes.
  • Stronger RESET circuit.
  • Atmega 16U2 replace the 8U2.


  • Microcontroller: ATmega328
  • Operating Voltage: 5V
  • Input Voltage (recommended): 7-12V
  • Input Voltage (limits): 6-20V
  • Digital I/O Pins: 14 (of which 6 provide PWM output)
  • Analog Input Pins: 6
  • DC Current per I/O Pin: 40 mA
  • DC Current for 3.3V Pin: 50 mA
  • Flash Memory: 32 KB (ATmega328) of which 0.5 KB used by bootloader
  • SRAM: 2 KB (ATmega328)
  • EEPROM: 1 KB (ATmega328)
  • Clock Speed: 16 MHz

On our YouTube Channel you will find a range of interesting video tutorials. They cover a wide use of Arduino Uno R3 features such as Pulse Width Modulation (PWM), Real-Time Clock (RTC), RGB LED, Serial Monitor, Stepper Motor, Thermal Array, RFID, Data logging, and many more.

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Additional Information

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28 Reviews

  • 5
    Title of review 454

    Posted by mrglennjon on 12th Dec 2012

    i love this arduino, its perfect for my electronics projects! it came superbly packaged as usual and a fast delivery time. i strongly recommend ordering from proto-pic they have never let me down.

  • 5
    Title of review 453

    Posted by Jago Lee on 11th Oct 2012

    Came well packaged and in working order!

  • 5
    Title of review 452

    Posted by Dave Boult on 4th Sep 2012

    Arrived the very next day and what a cracking product. I'm new to both Arduino and electronics so I'll no doubt be back for more bits and pieces (in fact, I already have been...)Excellent service, a great range and great prices too.

  • 5
    Title of review 451

    Posted by John on 11th Jul 2012

    I bought this and the Adafruit motor shield. Both arrived within a couple of days and have been working ever since. Great price & service.

  • 5
    Title of review 450

    Posted by Arduino fo on 3rd May 2012

    This is a great little board that can be programed using the free Visual Studio plugin called Visual Micro. Visual Studio allows us to easily understand code, drill down into compiler errors and much more.

  • 5
    Title of review 449

    Posted by Ewan on 1st Mar 2012

    Thanks very much!

  • 5
    Title of review 448

    Posted by Noah Schil on 1st Mar 2012

    As well as David Stone, I bought one of these elsewhere and it was faulty. I ordered one from here and it came directly the next day! For an amazing price. Amazing! I wouldn't buy ANY Arduino from anywhere else in the UK compared to here. Great shop

  • 5
    Title of review 447

    Posted by David Ston on 26th Feb 2011

    I bought one of these elsewhere and it was faulty, the seller didnt want to know. The guys at Proto-PIC sorted the problem out for me, ive since bought another 3 from them! Its a great piece of kit at a great price.

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