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 ceramic resonator, 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 Atmega16U2 (Atmega8U2 up to version R2) programmed as a USB-to-serial converter.
Microcontroller: ATmega328. Operating Voltage: 5V. Input Voltage (recommended): 7-12V. Input Voltage (limits): 6-20V. Digital I/O Pins: 14 (of which 6 provide PWM output). Analog Input Pins: 6. DC Current per I/O Pin: 40 mA. DC Current for 3.3V Pin: 50 mA. Flash Memory: 32 KB (ATmega328) of which 0. 5 KB used by bootloader. SRAM: 2 KB (ATmega328). EEPROM: 1 KB (ATmega328). Clock Speed: 16 MHz.