The classic Arduino Nano is the smallest board to build your projects with. The Arduino Nano is a small complete and breadboardfriendly board
based on the ATmega328 (Arduino Nano 3.x). It has more or less the same
functionality of the Arduino Duemilanove but in a different package. It
lacks only a DC power jack and works with a MiniB USB cable instead
of a standard one.

• Microcontroller
  ATmega328

  Architecture
  AVR

• Operating Voltage
  5 V

• Flash Memory
  32 KB of which 2 KB used by bootloader
• SRAM
  2 KB
• Clock Speed
  16 MHz
• Analog IN Pins
  8

  EEPROM
  1 KB

• DC Current per I/O Pins
  40 mA (I/O Pins)
• Input Voltage
  712 V
• Digital I/O Pins
  22 (6 of which are PWM)
• PWM Output
  6
• Power Consumption
  19 mA
• PCB Size
  18 x 45 mm

  Weight
  7 g