Arduino UNO R3 SMD is the open source Embedded Development board launched by Arduino based on Atmega328 SMD Package Microcontroller. 
 
Microcontroller : ATmega328 SMD.
Operating Voltage : 5V.
Supply Voltage recommended :  7-12V DC.
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.