Arduino Micro Development Board

Arduino Micro Development Board is a microcontroller board based on the Atmel ATmega32u4. The board has 20 digital input/output pins (of which 7 can be used as PWM outputs and 12 as analog inputs), a 16 MHz crystal oscillator, a micro USB connection, an ICSP header, and a reset button. 

The board has everything needed to support the microcontroller. Simply connect it to a computer with a micro USB cable to get started. The form factor enables the board to be easily placed on a breadboard. 

The Micro is similar to the Arduino Leonardo in that the ATmega32u4 has built-in USB communication, eliminating the need for a secondary processor. This allows the Micro to appear to a connected computer as a mouse and keyboard, in addition to a virtual (CDC) serial / COM port.