#ifndefs don't work if i define in the sketch before the include
moved the pin initializations to the intialization function
library working using OC toggle to drive GS and interrupt for serial data
happy with where this is on an arduino uno. trying out a sfe pm
pro micro running at 8MHz just doesn't have the oomf to do more than one driver. shame.
changed a loop index to 16-bit because 8-bit would only fit two drivers
made serialCycle() private
got it working with three drivers with minimal stutter.