Overview of Stepper Motor

Stepper motor is a brushless DC motor that divides the full rotation angle of 360° into a number of equal steps.

The motor is rotated by applying a certain sequence of control signals. The speed of rotation can be changed by changing the rate at which the control signals are applied.

For more information about Stepper Motor and how to use it, refer the topic Stepper Motor in the sensors and modules section.

Connection Diagram of Stepper Motor with Arduino

Stepper Motor Control using Arduino Uno

Rotating stepper motor in clockwise and counter clockwise directions alternately.

Here, we are using six wire unipolar stepper motor. Only four wires are required to control this stepper motor. The two center tap wires of the stepper motor are connected to 5V supply.

ULN2003 driver is used to drive the stepper motor.

Note: To find winding coils and their center tap leads, measure resistance in between the leads. From center leads we will get half the resistance value as compared to the resistance between winding ends.

Stepper Motor Code for Arduino

void setup() {
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
}

void loop() {
	/* Rotation in one direction */
  for(int i = 0; i<12; i++)
  {
    digitalWrite(7, HIGH);
    digitalWrite(6, LOW);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    delay(100);
    digitalWrite(7, HIGH);
    digitalWrite(6, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    delay(100);
    digitalWrite(7, LOW);
    digitalWrite(6, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    delay(100);
    digitalWrite(7, LOW);
    digitalWrite(6, HIGH);
    digitalWrite(5, HIGH);
    digitalWrite(4, LOW);
    delay(100);
    digitalWrite(7, LOW);
    digitalWrite(6, LOW);
    digitalWrite(5, HIGH);
    digitalWrite(4, LOW);
    delay(100);
    digitalWrite(7, LOW);
    digitalWrite(6, LOW);
    digitalWrite(5, HIGH);
    digitalWrite(4, HIGH);
    delay(100);
    digitalWrite(7, LOW);
    digitalWrite(6, LOW);
    digitalWrite(5, LOW);
    digitalWrite(4, HIGH);
    delay(100);
    digitalWrite(7, HIGH);
    digitalWrite(6, LOW);
    digitalWrite(5, LOW);
    digitalWrite(4, HIGH);
    delay(100);
  }
  digitalWrite(7, HIGH);
  digitalWrite(6, LOW);
  digitalWrite(5, LOW);
  digitalWrite(4, LOW);
  delay(100);
  
	/* Rotation in opposite direction */
  for(int j = 0; j<12; j++)
  {
    digitalWrite(7, LOW);
    digitalWrite(6, LOW);
    digitalWrite(5, LOW);
    digitalWrite(4, HIGH);
    delay(100);
    digitalWrite(7, LOW);
    digitalWrite(6, LOW);
    digitalWrite(5, HIGH);
    digitalWrite(4, HIGH);
    delay(100);
    
    digitalWrite(7, LOW);
    digitalWrite(6, LOW);
    digitalWrite(5, HIGH);
    digitalWrite(4, LOW);
    delay(100);
    digitalWrite(7, LOW);
    digitalWrite(6, HIGH);
    digitalWrite(5, HIGH);
    digitalWrite(4, LOW);
    delay(100);
    
    digitalWrite(7, LOW);
    digitalWrite(6, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    delay(100);
    digitalWrite(7, HIGH);
    digitalWrite(6, HIGH);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    delay(100);
    
    digitalWrite(7, HIGH);
    digitalWrite(6, LOW);
    digitalWrite(5, LOW);
    digitalWrite(4, LOW);
    delay(100);
    digitalWrite(7, HIGH);
    digitalWrite(6, LOW);
    digitalWrite(5, LOW);
    digitalWrite(4, HIGH);
    delay(100);
  }
  digitalWrite(7, LOW);
  digitalWrite(6, LOW);
  digitalWrite(5, LOW);
  digitalWrite(4, HIGH);
  delay(100);
}

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Video of Stepper Motor Control using Arduino Uno