[Patrickwhite]

That error suggests that you are trying to initialize two things to the same PWM port. If all you have left are the drive system and sweeper subsystems, I would hazard a guess that either they are both trying to access PWM channel 2, or that somehow one of them (the one that uses PWM channel 2) is being initialized twice (the sort of scenario the singleton class is meant to prevent). Look through your getInstances to make sure they can only run the constructor once, make sure your constructors are private, and make sure there aren't any accidental calls to constructors outside of the subsystem classes.