Six new features of Arduino Uno R3

In Italian,the word "Uno" means one.It was named to remember the creation of Arduino 1.0.Now for most people who have interest in the Arduino Uno R3 projects,Arduino UNO R3 is the most advanced board in the Arduino world.
The Arduino Uno R3 board has six 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. In future, shields will be compatible with both the board that uses the AVR, which operates with 5V and with the Arduino Due that operates with 3.3V. The second one is a not connected pin, that is reserved for future purposes.
Stronger RESET circuit.
The Arduino Uno R2 has an ATMEGA8U2 USB microcontroller on board while the Arduino Uno R3 development board has an ATMEGA16U2 on it.It's more advanced than R2.
The arduino uno R3 board adds a diode across the USB ATMEGA reset pin pull-up resistor.

The USB Chip Position is different.On the Arduino Uno R2 board, the ATMEGA8U2 is positioned at 45 degrees. This is changed back to square position on the R3 board.
The Arduino Uno R2 has a LED and resistor connected in series on Arduino pin 13. The Arduino Uno R3 board protect this LED/resistor through a unity gain op-amp. This is the spare op-amp that was unused on previous boards.

Some parameters of Arduino Uno R3

Sainsmart Uno R3 is usually a microcontroller board dependent to the ATmega328. It's got 14 digital input/output pins, 6 analog inputs, a sixteen MHz crystal oscillator, a USB connection, a power jack, an ICSP header, and a reset button. It has almost everything essential to support the microcontroller. It is easy to attach it to a computer by a USB cable.

The board can function on an external supply of six to twenty volts. If supplied with considerably less than 7V,the 5V pin could provide less than five volts and the board might be unstable. If working with a lot more than 12V, the voltage regulator may perhaps overheat and hurt the board. The perfect range is seven to twelve volts.
The power pins:
VIN. The input voltage to the Arduino board when it making use of an external electric power source. It is possible to provide voltage by using of this pin.
5V. The regulated power supply to power the microcontroller as well as other elements around the board. This tends to appear either from VIN through an on-board regulator, or be equipped by USB or an additional regulated 5V source.
3V3. A 3.3 volt supply generated by the on-board regulator.
GND. Ground pins.
The Arduino Uno contains a lot of components to communicating with a computer, another Arduino, or other microcontrollers. The ATmega328 presents UART TTL (5V) serial conversation, which happens to be readily available on digital pins 0 (RX) and one (TX). An arduino ATmega8U2 on the board channels this serial communication above USB and seems like a digital comport to software program on the computer.On the other hand, on Windows, a .inf file is required. The Arduino software has a serial monitor which allows textual statistics to generally be despatched to and from the Arduino board