A4988 Stepper Motor Driver Module

published: 25 October 2020 / updated 25 October 2020

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Caractéristiques

The A4988 is a complete Microstepping Motor Driver with built-in translator for easy operation. The driver has a maximum output capacity of 35 V and ± 2 A. It can operate bipolar stepper motors in full-, half-, quarter-, eighth-, and sixteenth-step modes.

A4988 Stepper Driver Module Features:

Alternatives for A4988: DRV8825, L6474, L6207, L6208, TMC2208, TMC2209

Pin Configuration

Pin Name Description
VDD & GND Connected to 5V and GND of Controller
VMOT & GND Used to power the motor
1A, 1B, 2A, 2B Connected to the 4 coils of motor
DIRECTION Motor Direction Control pin
STEP Steps Control Pin
MS1, MS2, MS3 Microstep Selection Pins
SLEEP Pins For Controlling Power States
RESET
ENABLE

How to Use A4988 Driver Module

As mentioned earlier A4988 has an inbuilt translator, so only two wires are required to connect it to controller board. Circuit Diagram for interfacing A4988 module with a microcontroller to control a stepper motor is shown below.

As shown in above diagram only two pins DIR and STEP of module is connected with Arduino. STEP pin used to control the steps while DIR pin is used to control direction. Micro-step pins (MS1, MS2 and MS3) are used to operate the driver module in different step functions. In the above circuit MS1, MS2, and MS3 pins left disconnected, that means the driver will operate in full-step mode. This motor driver has low-ESR ceramic capacitors on board, which makes it vulnerable to voltage spikes, so it is advised to use at least 47µf capacitor across motor power supply pins. Stepper Motor wires is connected with output pins (1A, 1B, 2A & 2B) of driver module. It is commonly used in controlling the NEMA series stepper motors like NEMA17, NEMA23, and NEMA34

Microstepping Resolution Truth Table

MS1MS2MS3 Microstep Resolution Excitation Mode
LLL Full Step2 Phase
HLL Half Step1-2 Phase
LHL Quarter StepW1-2 Phase
HHL Eighth Step2W1-2 Phase
HHH Sixteenth Step4W1-2 Phase