Arduino Nano is a surface mount breadboard compatible embedded version of Arduino with integrated USB. It is the smallest, complete and breadboard friendly Arduino module. It has everything that Diecimila/Duemilanove has (electrically) with more analog input pins and onboard +5V AREF jumper. Physically, it is missing a power jack. The Nano automatically senses and switches to the higher potential source of power, so, there is no need for the power select jumper.
The Nano 3.0 has a number of facilities for communicating with a computer, another Arduino, or other microcontrollers. The ATmega328 provides UART TTL (5V) serial communication, which is available on digital pins 0 (RX) and 1 (TX).
A CH340G chip (replaces FTDI FT232RL) on the board channels this serial communication over USB and the CH40G drivers (included with the Arduino software) provide a virtual com port to software on the computer. The Arduino software includes a serial monitor which allows simple textual data to be sent to and from the Arduino board. The RXand TX LEDs on the board will flash when data is being transmitted via the CH340G chip and USB connection to the computer (but not for serial communication on pins 0 and 1).
Operating Voltage (logic level):5 V
Input Voltage (recommended):7-12 V
Input Voltage (limits):6-20 V
Digital I/O Pins:14 (of which 6 provide PWM output)
Analog Input Pins:8
DC Current per I/O Pin:40 mA
Flash Memory:32 KB (of which 2KB used by bootloader)