... analog inputs), a 16 MHz crystal oscillator, a micro USB connection, a power jack, an ICSP header, and ... simply connect it to a computer with a USB cable or power it with a AC-to- ... preceding boards in that the ATmega32u4 has built-in USB communication, eliminating the need for a secondary processor. ... , in addition to a virtual (CDC) serial / COM port. It also has other implications for the behavior of ...