This port allows to use the ATWILC3000 connected via UART with BTstack running on a POSIX host system, see test setup below (which lacks a proper RESET button).
At start, the firmware file is first uploaded to the ATWILC3000, before BTstack start up.
Please note that it configures the ATWILC3000 for a higher baud rate it does not detect if the firmware has already been downloaded, so you need to reset the ATWILC3000 before starting an example.
Tested with the official [ATWILC3000 SHIELD](http://www.microchip.com/DevelopmentTools/ProductDetails.aspx?PartNO=ATWILC3000-SHLD) on OS X.