Arduino Uno Rev3 is a microcontroller board based on the ATmega328P, an 8-bit microcontroller with 32KB of Flash memory and 2KB of RAM. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started. The Uno board is the first in a series of USB boards and it is the reference model for the Arduino platform.
Schematics: https://www.arduino.cc/en/uploads/Main/Arduino_Uno_Rev3-schematic.pdf Reference Design: https://www.arduino.cc/en/uploads/Main/arduino_Uno_Rev3-02-TH.zip











