support for arduino pro micro

[jadeiseepy]

no idea if it's the same as the sparkfun promicro, but i tried running the USART example on mine and it doesn't work :(

also, it's probably worth mentioning that in order to access the serial, i have to unplug it and plug it back in again to get the board's serial port to show up again.

[Rahix]

The Arduino Pro Micro has an ATmega32U4 microcontroller which speaks USB directly instead of having a UART connected to a separate UART-to-USB chip.

You either have to connect a separate UART-to-USB to the RX/TX pins of the Arduino Pro Micro or do your own USB-serial on the ATmega32U4. The latter is very involved, see #40 and #572.