The A4988 Stepper Motor Driver Carrier from Pololu is a breakout board for Allegro’s A4988 microstepping bipolar stepper motor driver. The A4988 includes a fixed off-time current regulator, an adjustable potentiometer for setting the maximum current output, and protection against over-temperature and under-voltage. The carrier board provides an operating voltage range comfortably above and below the typical 5–15 V range of A4988 itself. It also offers a big prototyping area and an extra row of pins that breaks out the rest of the A4988 pins, broken out along with other commonly used pins such as the microcontroller I/O lines, the EN and MS3 pins, the current control pins and the power connections. The A4988 is designed to drive bipolar stepper motors, and it is capable of outputting up to 2 A per winding without additional cooling or heatsinking. Its adjustable current control lets you set the maximum current output with a potentiometer, which lets you use voltages above your stepper motor’s rated voltage to achieve higher step rates. The A4988 Stepper Motor Driver Carrier from Pololu includes two dedicated flyback diodes that protect the IC and provide superb spike immunity. The on-board 3.3 V regulator allows the logic level of the control lines coming from the microcontroller to be safely reduced from 5 V to 3.3 V. Besides its ability to drive a bipolar stepper motor up to 2 A, the A4988 features adjustable rise and fall times, as well as built-in translator which makes it easy to control in many applications with just two microcontroller pins and eliminating the need for a library.