Arduino UNO R3 is a board for all engineers. Whatever may be the task, simple or complex Arduino UNO will fit your work. Arduino uno is a ATMEGA328 based development kit. Arduino is a open source hardware and detailed specification will disclosed in the arduino website.
Arduino UNO is the best microcontroller development board having all in one functionality, versatile example will really make you crazy about this stuff. You can easily interface GSM Modem, GPS, Bluetooth, wifi, touch screen, TFT modules, and motor drivers for your robotics very easily. Programming is very simple in Arduino. It is some what java based scripting function.
1.It has 14 digital Input/output pins
2.PWM output on 6 GPIO's
3.Six Analog Inputs
4.16Mhz Crystal oscillator