A4988 Stepper Motor Driver Module with Heat Sink

Microstepping bipolar stepper driver (up to 1/16), 8-35V, standard RAMPS/3D-printer StepStick.

₹85 + 18% GST

SKU: BOTBIT-MOT-06 · Best for: Desktop FDM 3D printers on RAMPS 1.4, MKS and similar boards

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Overview

About A4988 Stepper Motor Driver Module with Heat Sink.

The A4988 is the classic StepStick microstepping driver for bipolar stepper motors, built around Allegro's A4988 chip. It is the driver that made desktop 3D printers and small CNC machines affordable, and it remains the default StepStick for RAMPS 1.4 boards, CNC shields and countless motion projects. It supports microstepping down to 1/16 step, an adjustable current limit via a trim potentiometer, and a simple STEP/DIR interface.

It is popular in India because it is cheap, tiny, standard-pinout and works with almost every NEMA 17 stepper. The included heat sink lets it run closer to its ~1A-per-phase continuous rating without thermal shutdown. Any motion-control firmware -- Marlin, GRBL, Klipper -- supports it, so it drops straight into existing printer and router electronics.

The A4988 accepts a logic supply of 3-5.5V and a motor supply of 8-35V, has built-in over-current and thermal protection, and needs only two microcontroller pins (STEP and DIR) to run once the microstep and enable pins are configured.

Key features

Why it stands out.

Adjustable current limit via onboard trim-pot for tuning to your motor

Microstepping resolution of full, 1/2, 1/4, 1/8 and 1/16 step (set by MS1/MS2/MS3)

Simple STEP/DIR interface -- two pins run the motor

Wide 8-35V motor supply, separate 3-5.5V logic supply

Built-in over-current, thermal-shutdown and crossover-current protection

Standard StepStick pinout for RAMPS 1.4, CNC shield and MKS boards, with heat sink included

Specifications

Selection facts.

Driver IC	Allegro A4988
Motor type	Bipolar stepper
Motor supply voltage (VMOT)	8 - 35V DC
Logic supply voltage (VDD)	3 - 5.5V
Continuous current per phase	Up to ~1A without heat sink, ~2A with heat sink/cooling
Peak current per phase	2A max
Microstep resolutions	Full, 1/2, 1/4, 1/8, 1/16
Control interface	STEP / DIR (plus ENABLE, MS1-MS3, RESET, SLEEP)
Protection	Over-current, thermal shutdown, crossover-current
Board format	StepStick / Pololu-compatible carrier

Applications

Where it is used.

Desktop FDM 3D printers on RAMPS 1.4, MKS and similar boards
Small CNC routers, engravers and plotters using GRBL and a CNC shield
XY/XYZ stages and camera sliders needing microstep precision
Automated dispensing, pick-and-place and lab automation rigs
Any NEMA 17 or NEMA 14 bipolar stepper positioning project

Buying guide

How to choose.

Buy the A4988 if you need an inexpensive, standard driver for a bipolar stepper up to about 1-1.5A per phase and 1/16 microstepping is enough. It is the safe default for a first 3D printer or GRBL CNC. If you need finer microstepping, higher current or silent operation, look at the DRV8825 (up to 1/32, ~2.2A) or TMC2209 (silent, 1/256).

Always set the current limit before running a motor: measure the Vref on the trim-pot and calculate the current from the board's sense-resistor value, or set current = Vref / (8 x Rsense). Under-setting causes missed steps; over-setting overheats the motor and driver. Use the heat sink and, for enclosed printers, add a small fan.

Pair it with a NEMA 17 bipolar stepper (4-wire), an 8-35V supply sized for your motors, and a controller running Marlin, GRBL or Klipper. Buy a spare -- StepSticks are consumable and can fail if the motor is unplugged while powered.

FAQ

Common questions.

How do I set the current limit?

Turn the small trim-pot while measuring Vref (the voltage on the pot wiper relative to GND). Current limit depends on the sense resistors: for common 0.1 ohm boards, current ~= Vref / 0.8 x adjustment; check your board's silkscreen or use the manufacturer formula. Set it just below your motor's rated current.

Which pins do I wire to my microcontroller?

At minimum connect STEP and DIR to two GPIO pins, tie RESET and SLEEP together (or high), pull ENABLE low to enable, and set MS1/MS2/MS3 for your microstep mode. VMOT/GND take the motor supply and VDD/GND take logic power.

Will it work on my RAMPS 1.4 / CNC shield?

Yes. The A4988 uses the standard StepStick pinout and plugs directly into RAMPS 1.4, the Arduino CNC shield, MKS boards and most 3D-printer mainboards. Mind the orientation printed on the board.

Can it run a 28BYJ-48 or unipolar motor?

No. The A4988 is for bipolar (4-wire) steppers such as NEMA 17. A unipolar motor like the 28BYJ-48 needs a ULN2003 board instead, unless you rewire it to bipolar.

Why does my motor skip steps or the driver get hot?

Usually the current limit is set wrong or cooling is inadequate. Set Vref correctly, fit the heat sink (included), add airflow, and never unplug the motor while VMOT is powered, as that can destroy the chip.

Is it available in India and what is in the box?

Yes, it is widely stocked in India. The package typically includes one A4988 StepStick module with a stick-on aluminium heat sink; wiring, motor and controller are separate.