Interfacing Stepper motorInterfacing Stepper motor

IntroductionIntroductionStepper motor is different for

ordinary motorsIt has named before the operation

and structure of the motor.Yes,ofcourse the motor runs in

steps and has many winding typesMotor was classified into two types

in both categories

ClassificationClassificationBased on windings

permanent-magnet (PM) stepper motors, variable-reluctance (VR) stepper motors, hybrid stepper motors

Based on steps 4 – steps 8 – steps

permanent-magnet stepper motor ◦The permanent-magnet stepper motor

operates on the reaction between a permanent-magnet rotor and an electromagnetic field. A basic two-pole PM stepper motor

Variable-reluctance Stepper Motors◦The variable-reluctance (VR) stepper

motor differs from the PM stepper in that it has no permanent-magnet rotor and no residual torque to hold the rotor at one position when turned off.

Permanent-magnet (PM) Stepper Motors

(a)PM stepper motor; (b) 90 step; (c) 45 step.

Variable-reluctance stepper motor and switching sequence.

A 4 – step stepper motorA 4 – step stepper motor

Connection of 4 – step Connection of 4 – step stepper motorstepper motor

Basic concept Basic concept If you give supply to the windings,

they started to get magnetized, and “the same poles repelled each other and opposite poles attract each other” concept is applicable for magnetized coil and inner magnetic shaft

The shaft started to move to the portion where there is no magnetic force to free itself.

At this position if the voltage applied to the coil changes continuously, motor also starts to rotate continuously.

Programming conceptProgramming conceptStart from the beginning , we are

going to give some 4 binary values from either microcontroller or PC.

As we know what to do for giving values form microcontroller, we can assign a char to give that value to particular port by using sfr.

That is it, value passed to motor and the motor rotates………

Program structureProgram structure#include<reg51.h>Sfr motordata=0x90; // Port 1 for motor

interfaceSbit control =P2^1; // controlling the motorVoid main(){Control=1;motordata=0;While(1){ If(control==1){motordata=0x88;

Program structure contd.Program structure contd. motordata =0x44; motordata=0x22; motordata=0x11; } else { motordata=0x88; motordata =0x11; motordata=0x22; motordata=0x44; } } }

Assignment for next classAssignment for next classRotate a particular degree in

motor

Rotate the motor 45* both clockwise and anticlockwise continuously.

Calculate the number of steps required for full rotation.