USB to UART bridge

Dependencies:   USBDevice mbed

Fork of XBee-ExplorerLite by Norimasa Okamoto

UARTpinout
TXDp9
RXDp10
RTSp5
DTRp6

Windows serial driver:
https://developer.mbed.org/handbook/USBSerial
https://developer.mbed.org/media/uploads/samux/serial.zip