How to interface the Stepper Motor with 8051

Stepper Motor

Stepper Motor

A stepper motor is a brushless DC motor that divides a full 360° rotation into a series of equal steps.

The motor rotates by following a specific sequence of control signals, and its speed can be adjusted by changing the rate of these signals. Stepper motors come in a variety of step angles and torque ratings to suit different applications.

A microcontroller can be used to send control signals to the motor, enabling precise rotation as needed for specific tasks.

For more details on stepper motors and their usage, refer to the “Stepper Motor” section in the sensors and modules category.

Stepper Motor Connection with 8051 using ULN2003

In this example, we’ll interface a 6-wire unipolar stepper motor with an 8051 microcontroller.

Only four wires are needed to control the stepper motor, while the two common wires are connected to a 5V supply. A ULN2003 driver is used to drive the stepper motor effectively.

To identify the winding coils and their center tap leads, measure the resistance between the leads. The center tap leads will show half the resistance value of each winding.

Example

Let’s program the AT89S52 to rotate the stepper motor 360° clockwise using a half-step sequence and 360° counterclockwise using a full-step sequence.

8051 Stepper Motor Code

#include <reg52.h>

#define Stepper_Port P2			/* Define Stepper Motor Port */

/* Function to provide delay of 1ms at 11.0592 MHz */
void delay(unsigned int count)
{
    int i,j;
    for(i=0; i<count; i++)
			for(j=0; j<112; j++);
}

int main(void)
{
	int i,period;
	period = 100;	/* Set period in between two steps of Stepper Motor */
	while (1)
	{
		/* Rotate Stepper Motor clockwise with Half step sequence */
		for(i=0; i<12; i++)
		{
			Stepper_Port = 0x09;
			delay(period);
			Stepper_Port = 0x08;
			delay(period);
			Stepper_Port = 0x0C;
			delay(period);
			Stepper_Port = 0x04;
			delay(period);
			Stepper_Port = 0x06;
			delay(period);
			Stepper_Port = 0x02;
			delay(period);
			Stepper_Port = 0x03;
			delay(period);
			Stepper_Port = 0x01;
			delay(period);
		}
		/* last one step to acquire initial position */ 
		Stepper_Port = 0x09;
		delay(period);
		delay(1000);
		/* Rotate Stepper Motor Anticlockwise with Full step sequence */
		for(i=0; i<12; i++)
		{
			Stepper_Port = 0x09;
			delay(period);
			Stepper_Port = 0x03;
			delay(period);
			Stepper_Port = 0x06;
			delay(period);
			Stepper_Port = 0x0C;
			delay(period);
		}
		Stepper_Port = 0x09;
		delay(period);
		delay(1000);
	}
}