issues interfacing with OS X

I'll need to look at this - unless someone else gets there first ;)

I imagine it's something that needs to be set up with stty. On Raspberry Pi I've used:

stty -F /dev/ttyAMA0 9600 -parenb -parodd cs8 hupcl -cstopb cread clocal -crtscts ignbrk raw min 0 time 5

but there may be different settings needed on Mac. If I'm honest I'm not 100% sure on this, but it's probably just a matter of turning flow control off.