The Arduino source for this can be found on the project GitHub. Whilst [Frank] mentions that this assembly has a weight and torque advantage over a NEMA 17 sized stepper motor, but we see no hard ...

Adjust the phase current, crank up the microstepping, and forget about it — that’s what most people want out of a stepper motor driver ... of the underlying Arduino through its AUX3 pin ...

So you finally decided to hop on the Arduino bandwagon and start making ... and LED to the more advanced microSD card reader ...