A4988 Stepper Motor Driver Carrier with Voltage Regulators A4983/A4988 stepper motor driver carrier with voltage regulators with dimensions. Overview This product is a carrier board or breakout board for Allegros A4988 DMOS Microstepping Driver with Translator and Overcurrent Protection we therefore recommend careful reading of the A4988 datasheet (380k pdf) before using this product. This stepper motor driver lets you control one bipolar stepper motor at up to 2 A output current per coil (see the Power Dissipation Considerations section below for more information). Here are some of the drivers key features: Simple step and direction control interface Five different step resolutions: full-step, half-step, quarter-step, eighth-step, and sixteenth-step Adjustable current control lets you set the maximum current output with a potentiometer, which lets you use voltages above your stepper motors rated voltage to achieve higher step rates Intelligent chopping control that automatically selects the correct current decay mode (fast decay or slow decay) Over-temperature thermal shutdown, under-voltage lockout, and crossover-current protection Short-to-ground and shorted-load protection This carrier has reverse power protection on the main power input and built-in 5 V and 3.3 V voltage regulators that eliminate the need for separate logic and motor supplies and let you control the driver with microcontrollers powered at 5 V or 3.3 V. We also sell a smaller, higher-performace version of the A4988 carrier without voltage regulators. Like nearly all our other carrier boards, this product ships with all surface-mount components including the A4988 driver ICinstalled as shown in the product picture.Some unipolar stepper motors (e.g. those with six or eight leads) can be controlled by this driver as bipolar stepper motors. For more information, please see the frequently asked questions. Unipolar motors with five leads cannot be used with this driver. Included Hardware The A4988 stepper motor driver carrier with voltage regulators comes with 0.1 male header pins that can be broken into smaller strips and soldered in for use with solderless breadboards or 0.1 female connectors. You can also solder your motor leads and other connections directly to the board. Using the driver Minimal wiring diagram for wiring a 5V microcontroller to an A4983/A4988 stepper motor driver carrier with voltage regulators (full-step mode). Power connections The driver requires a logic supply voltage (3 5.5 V) to be connected across the VDD and GND pins and a motor supply voltage (8 35 V) to be connected across VMOT and GND. The logic voltage can be supplied from an external source, such as that powering the logic of the rest of the system, or by jumpering the output of the 5 V or 3.3 V voltage regulator outputs to VDD. There are also surface-mount pads that allow VDD selection to be made by making a solder bridge across the appropriate pads. Note that the drivers regulators can also be used to power other electronics in the system, such as the controlling MCU. The motor power supply should be capable of delivering the expected currents for the stepper motors being used (peaks up to 4 A). Motor connections Four, six, and eight-wire stepper motors can be driven by the A4988 if they are properly connected a FAQ answer explains the proper wirings in detail.