Pololu 2128 breakout board for a4988 stepper motor driver pololu 2128 this stepper motor carrier is a breakout board designed for use with the b a4988 b dmos microstepping bipolar stepper motor driver the increased performance from the 4 layer pcb improves thermal performance allowing the driver to deliver 20 more current than previous carriers the breakout board gives five different step resolutions full step half step quarter step eighth step and sixteenth step and there is adj