This document presents a case study on interfacing a stepper motor with an 8086 microprocessor. It includes the following: 1) An overview of stepper motors, their windings, and protection of the windings. 2) A design to control a 4-phase stepper motor with clockwise and anticlockwise rotations using an 8086 program and hardware circuit. 3) The program uses assembly language instructions to output step signals to the motor in the proper sequence to rotate the shaft.

1. A Case Study on
CASE STUDY ON STEPPER MOTOR
Presentation by:
Ravada Tarun Kumar (17981A04I2)
Thadi Prem Kumar (17981A04K4)
Bikkina Mahesh (18985A0428)
S Dileep Kumar (17981A04I7)
Department of Electronics & Communication Engineering
RAGHU ENGINEERING COLLEGE
Visakhapatnam-531162 1

2. Question
 Design the stepper motor interfacing with 8086 using the
following specifications
 A) Identify the components required for the application
 B) Give the design (Block diagram and schematic diagrams)
 C) Develop the program using 8086 assembly language
 D) Show the output using Kit/Simulation tool
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3. Contents
 Stepper motor
 Stepper motor windings
 Winding arrangement
 Protection of winding
 Stepper motor design
 Interfacing program
 Hardware circuit
 Conclusion
 References
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4. Stepper motor
 It is a device used to obtain an accurate position control of
rotating shaft.
 The rotation of the shaft will be in the terms of steps.
 To rotate the shaft of the stepper motor, a sequence of pulses
is needed to be applied to the winding of the stepper motor,
in proper sequence.
 The number of pulses required for one complete rotation of
the shaft of the stepper motor are equal to its number of
internal teeth on rotor.
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5. Stepper motor
 The stator teeth and rotor teeth lock with each other to fix a
position of the shaft.
 With pulse applied to the winding input, the rotor rotates by
one teeth position or an angle ‘x’.
 The angle ‘x’ may be calculated
X = 360 degrees
No.of rotor teeth
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6. Stepper motor
 The typical stepper may have parameters like torque 3kg-cm,
operating voltage 12v, current rating 0.2A and a step angle 1.8
degrees.
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7. Stepper motor windings
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8. Stepper motor rotor
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9. Winding arrangement
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10. Protection of winding
 We have to protect the winding of stepper motor.
 Parallel to the winding ‘a’, they connected a diode.
 When the excess currents flows through that winding then
that diode will break down and the large current will flow
through that diode and that winding ‘a’ will be protected.
 The reason is that the current will always offer a low
resistance path.
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11. Protection of winding
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12. Stepper motor design
 We are going to design a stepper motor controller and writing
a ALP to rotate shaft of a 4-phase stepper motor. In clock 5
rotations and in anticlockwise 5 rotations.
Motion step A B C D
clockwise 1 1 0 0 0
2 0 1 0 0
3 0 0 1 0
4 0 0 0 1
5 1 0 0 0
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13. Stepper motor design
Motion step A B C D
Anticlockwise 1 1 0 0 0
2 0 0 0 1
3 0 0 1 0
4 0 1 0 0
5 1 0 0 0
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14. Interfacing program
ASSUME CS : CODE
CODE SEGMENT
START: MOV AL,80H
OUT CWR,AL
MOV AL,88H
MOV CX,1000
AGAIN1: OUT PORT A,AL
CALL DELAY
ROL AL,01
DEC CX
JNZ AGAIN1
MOV AH,88H
MOV CX,1000
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15. Interfacing program
AGAIN2: OUT PORT A,AL
CALL DELAY
ROR AL,01
DEC CX
JNZ AGAIN2
MOV AH, 4CH
INT 21H
CODE ENDS
END START
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16. Hardware circuit
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17. Conclusion
 In this way we can Design a stepper motor interfacing
with 8086 using the following specifications
 A) Identify the components required for the application
 B) Give the design (Block diagram and schematic
diagrams)
 C) Develop the program using 8086 assembly language
 D) Show the output using Kit/Simulation tool
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18. References
 https://www.google.com/search?q=steppermotor&aps+chro
me..69i57j0I3.1323j0j7&client=ms-android-
vivo&sourceid=chrome-mobile&ie=UTF-8
 https://www.google.com/search?q=intefacing&aps+chrome..
69i57j0I3.1323j0j7&client=ms-android-
vivo&sourceid=chrome-mobile&ie=UTF-8
 https://www.google.com/search?q=simulation
techniques&aps+chrome..69i57j0I3.1323j0j7&client=ms-
android-vivo&sourceid=chrome-mobile&ie=UTF-8
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19. THANK YOU
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