This is a special SMD version (rev. #2) of the UNO with a
surface mount version of the ATmega328. Functionally this
version is the same as the regular UNO, but uses the smaller
size ATmega which is soldered onto the printed circuit board.
The Arduino Uno is a microcontroller board based on the
ATmega328 (datasheet). It has 14 digital input/output pins (of
which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz
crystal oscillator, a USB connection, a 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 a AC-to-DC adapter or battery
to get started. The Uno differs from all preceding boards in
that it does not use the FTDI USB-to-serial driver chip.
Instead, it features the Atmega8U2 programmed as a USB-to-serial
converter."Uno" means one in Italian and is named to mark the
upcoming release of Arduino 1.0. The Uno will be the reference
versions of Arduno, moving forward. The Uno is th