Arduino Uno R3

Arduino Uno is a microcontroller board based on the ATmega328P. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, 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 an AC-to-DC adapter or battery to get started. You can tinker with your UNO without worry too much about doing something wrong, worst case scenario you can replace the chip for a few dollars and start over again.
Arduino Uno Rev 3 is the ideal board for getting started with electronics, through fun and engaging hands-on projects. This board is one of the best entry to the unique Arduino experience and an essential tool for your rapid prototyping needs. Uno Rev 3 is perfect for learning the basics of how sensors and actuators work. Arduino Uno is the first in a series of USB-based Arduino boards.