: 1. The Pro Micro is to the Pro mini except with a ATmega32U4 on board. The USB transceiver inwardly the 32U4 us to add USB connectivity on board and do away with large foreign USB interface. . . This petite piddling board all of the neat-o Arduino tricks that you 're fellow with : 4 channels of 10-bit ADC, 5 PWM pins, 12 DIOs as well as hardware serial connections Rx and Tx. Running at 16 MHz and 5V, this board will you a lot of your past favourite Arduino-compatible boards but this piddling guy can go just about anywhere. If you 're supplying unregulated power to the board, be to connect to the `` RAW '' pin on not VCC. : ATmega32U4 running at 5V/16MHz Supported by Arduino IDE v1 .0.1 On-Board Micro-USB connector for programming 4 x 10-bit ADC pins, 12 x Digital I/Os Rx and Tx Hardware program Connections Note : When you start the Arduino IDE software, pls go to the tool and choose the board `` Arduino Leonardo '' Package included : 3 * Pro Micro ATmega32U4 5V/16MHz Development Board .