A000010

A000010 Arduino Uno is a microcontroller board based on the ATmega328 (datasheet). It has 14 io pins, 6 Analogue inputs, a 16MHz crystal oscillator, a USB connection, a power jack, an ICSP header and a reset button. Uno differs from all preceding boards in that it does not use the FTDI USB to serial driver chip. Instead, it features ATmega16U2 programmed 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 DFU mode. Revision 3 of the board has the following new features: 1.0 pin out: 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 both with the board that use the AVR, which operate with 5V and with the Arduino Due that operate with 3.3V.