Hi all, I realize this is an ancient thread. However, after dealing with lots of strange issues with the serial device on Mac/OSX I just broke down and used libusb. Here’s a really crappy UDP server that reads x y data from UDP packets and controls 2 servos accordingly: gist.github.com/asm/8b5217ed6d688c26ad70. Hopefully this will help someone 
Note the controller sends its data back in packed form so the structs in the protocol.h that comes with the SDK won’t work on architectures that byte align.