Extending Firmata For Stepper Motor Control

Excellent forum - this is my first post.

I need to strobe a digital pin smoothly for my stepper motor and so I thought to extend the FirmataClass and add a message type & function to handle it.

void StrobeFirmataClass::strobeDigitalPin(byte pin, int count, int period, float dutyCycle=.5);

So I think I could extend FirmataClass within the Arduino IDE and add this function & override processInput() but I'm not quite there.

Does anyone have an example of a descendant of FirmataClass? I started doing it in C++ but compiling Firmata with g++ turned into a huge pain in OSX. (Hence me trying to do this in the Arduino IDE.)

Thanks, Joe