The Arduino Uno is a microcontroller board based on the ATmega328. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with an 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 Atmega16U programmed as a USB-to-serial converter.
Features:
Digital I/O pins: 14 (of which 6 provide PWM output)
Analogue input pins: 6
Contains: 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset button
Specifications:
Power supply: 6-20 V max. (adapter not included)
Microcontroller: ATmega328
Digital I/O pins: 14 (of which 6 provide PWM output)
DC current per I/O pin: 40 mA
DC current for 3.3 V pin: 50 mA
Analogue input pins: 6
Flash memory: 32 kB (ATmega328) of which 0.5 KB used by bootloader