Pololu
A4988 Stepper Motor Driver Carrier
A breakout board for the Allegro A4988 DMOS microstepping stepper motor driver with translator and overcurrent protection. It lets you control one bipolar st...
Get notified when back in stock
A breakout board for the Allegro A4988 DMOS microstepping stepper motor driver with translator and overcurrent protection. It lets you control one bipolar stepper motor at up to 2 A per coil (with sufficient cooling) using a simple step-and-direction interface.
The board ships with all surface-mount components installed. A 1×16-pin breakaway 0.1″ male header is included but not soldered, ready for use with breadboards or 0.1″ connectors.
Key Features
- Simple Control Interface – Step and direction pins for easy microcontroller integration
- Five Microstep Resolutions – Full, half, quarter, eighth, and sixteenth step
- Adjustable Current Limiting – Onboard potentiometer sets the maximum output current, allowing voltages above the motor's rated voltage for higher step rates
- Intelligent Chopping Control – Automatically selects fast or slow current decay mode
- Built-In Protection – Over-temperature thermal shutdown, under-voltage lockout, crossover-current, short-to-ground, and shorted-load protection
- Motor Supply – 8–35 V
- Logic Supply – 3–5.5 V
- Max Current – 2 A per coil (with heat sink; ~1 A without)
Current Limit Setting
The current limit can be set by measuring VREF on the board. The formula is:
IMAX = VREF / (8 × RCS)
where RCS is 0.068 Ω on boards manufactured from January 2017 (0.050 Ω on earlier boards). For example, for a 1 A current limit with 68 mΩ sense resistors, set VREF to 540 mV.
Microstep Resolution
- MS1 Low, MS2 Low, MS3 Low – Full step
- MS1 High, MS2 Low, MS3 Low – Half step
- MS1 Low, MS2 High, MS3 Low – Quarter step
- MS1 High, MS2 High, MS3 Low – Eighth step
- MS1 High, MS2 High, MS3 High – Sixteenth step
Also Available
- A4988 Black Edition – four-layer PCB with ~20% better thermal performance
Resources
Package Contents
- 1× A4988 Stepper Motor Driver Carrier
- 1× 1×16-pin 0.1″ Male Header (not soldered)
Jargon buster
Plain-language definitions for the technical terms used above.
- breakout
- A breakout board carries a small or fine-pitched component and brings its connections out to standard, breadboard- and header-friendly pins. Describing a part as a breakout means it can be wired into a project without soldering directly to the component's tiny contacts.
- CS
- CS stands for chip select, a control pin used by SPI devices to tell which connected device should listen. It matters when you connect more than one SPI module to the same microcontroller, because each device usually needs its own CS pin.
- electrolytic capacitor
- An electrolytic capacitor is a type of capacitor that can store relatively large amounts of electrical charge in a small package. It is commonly used for smoothing power supplies, reducing noise, and short-term energy storage, but it usually has polarity so it must be installed the correct way around.
- GND
- GND is the ground or reference connection (0 V) for a circuit. When connecting two devices together, their grounds must be joined so both agree on what counts as a low or high signal.
- microcontroller
- A microcontroller is a small computer on a single chip that runs a stored program and controls connected inputs and outputs such as buttons, sensors, displays and communication interfaces. In a device built around one, it is the part that executes the code and coordinates the device's behaviour.
- motor driver
- An electronic circuit that lets a low-power controller switch and control a motor that needs more current than the controller pins can safely provide. Checking motor driver support matters because pumps and motors usually cannot be connected directly to a microcontroller output.
- PCB
- A printed circuit board (PCB) is a board, usually rigid, with etched copper tracks that connect electronic components together without loose wiring. Components are mounted on the board and signals route between them through the copper layout.
- potentiometer
- A variable resistor usually turned with a knob or shaft to create an adjustable electrical signal. It is often used for inputs such as volume, brightness or position, so it helps beginners learn how a microcontroller reads changing values.
Find this product in
Brands
Robotics & Motion
Resources & Downloads
Guides, code examples, and more
Related Tutorials
Free guides on learn.littlebird.com.au
