A microcontroller board called the Arduino Leonardo is based on the ATmega32u4 chip. It contains a 16 MHz crystal oscillator, 20 digital input/output pins, a micro USB port, a power jack, an ICSP header, and a reset button. It comes with everything needed to support the microcontroller; to get started, just plug in a USB cable, an AC-to-DC adapter, or a battery. The ATmega32u4 on the Leonardo is different from all other boards in that it includes built-in USB connectivity, doing away with the requirement for a separate processor.