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Microduino-A4982 is a DMOS micro-step drive with a converter and overcurrent protection. It can be used to operate bipolar steepper motors in full, half,1/4,1/8 and 1/16 step model.Widely used in control system.


  • Easily to control;
  • Four optional stepping modes:full, 1/2,1/4 and 1/16
  • Perfect protection mechanisms:
    • Overtemperature shutdown circuit, undervoltage lockout, crossover current protection;
    • Ground short circuit protection, load short-circuit protection;
  • Use potentiometer to adjust the current;
  • Automatic current decay mode detection / selection;
  • Compliance with smoke-free fire (NSNF) specification (ET package);
  • The unique plug way and more space savings.


  • Support bipolar stepper motor;
  • Just input a pulse for the "STEP", it will drives the motor to produce micro-step. Without the need for phase sequence tables, high frequency control lines, or complex interfaces to program;
  • The maximum output current can be adjusted via potentiometer, resulting in higher step rate;
  • Four optional stepping modes:
    • full,1/2,1/4 and 1/16;

Electrical Specifications

  • VCC voltage:
    • 3.3~5V
  • VMOT voltage:
    • 6~25V
  • Maximum operating current:
    • 1.4A
  • Under the Low current sleep mode, the current less than 10uA;
  • Automatic current decay mode detection/selection;
  • Overtemperature shutdown circuit, undervoltage lockout, crossover current protection;
  • Ground short circuit protection, load short-circuit protection;

Pin Description

Microduino A4982 Pin Microduino Pin function
STEP Microduino IO port Pulse drives the stepper motor produces micro-stepping
DIR Microduino IO port Control the rotation direction of the stepper motor
EN Microduino IO port Open or close the drive (active low)
VMOT External power source External power supply to the stepper motor
VCC VCC power to A4982 and Microduino


Eagle PCB File:Microduino-A4982.zip

Main component


Arduino library and support package

Stepper motor wiring

  • Stepper motor connects with Microduino A4982:
    • Four-wire two-phase stepper motor has two sets of coils a, b, the coil resistance is very small, only several ohms. a and b are totally insulated from the group, not communicating. Measured with a multimeter, connectivity is a set;
    • After measured out, a set of coils connect to OUT1A, OUT1B, another coil connects to OUT2A, OUT2B.
  • By changing the MS1 & MS2 to change the stepping mode (Microduino A4982 default is 1/16 step mode);


Program download

Testing Program:File:Program Test A4982.zip

A4982 Simple Application

  • Connect the Micorduino core module,Microduino A4982 and the stepper motor.
  • Prepared hardware:Microduino FT232R、Microduino Core、Microduino A4982、Four-wire two-phase stepper motor、9V~12V power;
  • Prepared software:Microduino provides testing program(Arduino part)、Arduino IDE(1.0 release upper)、AccelStepper library,
  • Put the downloaded library to the libraries folder of the Arduino IDE installation folder;
  • Strat Ardino IDE, open the testing program, card type chooses “Microduino Core (Atmega328P@16M,5V)”, download directly;
  • Use the pegboard setting up the circuit: (blue line at the bottom),as following picture:
Pegboard wiring diagram
  • Microduino A4982 drives a stepper motor:[ Test_A4982]
    • External 9V or 12V power supply, the motor does not rotate in initialization state;
    • Press the button, the stepper motor begins to rotate as setting speed, and LED indicator lights, reverse rotation after a few laps, the cycle repeated;
    • Press the button again to close the drive, LED indicator lights off. Key detection through an interrupt, turn the switch driver.


Microduino A4982 Front
Microduino A4982 Back
Microduino A4982 Erection