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Arduino Uno Rev3 Open-Source MCU has Digital and Analog I/Os

Written by Stephen Vicinanza

Arduino Uno Rev3 open-source MCU has digital and analog I/Os. Arduino’s microcontroller (MCU) board based on the Microchip ATmega328P microcontroller is open-source.

The board has 14 digital inputs/output pins, 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header, and a reset button. The Uno Rev3 has everything required to support the microcontroller users can just simply connect it to a computer with a USB cable or power it with an AC-to-DC adapter or battery to get started.

The long and short of it is there is very little that could go wrong when tinkering with an Arduino Uno. The worst that can happen is the user needs to replace the chip, for a few bucks.

The term Uno was chosen because it marks the release of the Arduino Software (IDE) 1.0. The Uno board and the software version 1.0 were reference versions of Arduino, which now evolved to newer releases. The Uno board is the first in a series of USB Arduino boards, and the reference model for the Arduino platform, for an extensive list of current, past or outdated boards, see the Arduino index of boards.


  • Microcontroller ATmega328P
  • Input Voltage 7-12V Input Voltage (limit) 6-20V
  • Digital I/O 14 (of which 6 provide PWM output)
  • PMW Digital I/O Pins 6
  • Analog Input Pins 6
  • DC Current per I/O pin 20 mA
  • DC Current for 3.3V Pin 50 mA
  • Flash Memory 32KB of which 0.5 KB is used by the bootloader
  • SRAM 2 KB
  • Clock Speed 16 MHz
  • Dimension L 68.6 mm W 53.4 mm Weight 25g

To find out more about the Arduino Uno Rev3 check out the product page here.

Arduino |

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For the past 8 years, I have been writing about embedded technologies, added to my technical, academic, and medical editorial experience, with companies like Elsevier and Cambridge University Press. I tell people to read what I write, not try to pronounce my last name. I am always available for comments and suggestions you can reach me at and I promise I will take the time to reach back out to you. I live in the North East with my wonderful family.

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Arduino Uno Rev3 Open-Source MCU has Digital and Analog I/Os

by Stephen Vicinanza time to read: 1 min