This technical report describes a project to control the speed of a stepper motor using a mobile phone. A mobile phone is interfaced with a microcontroller using a DTMF receiver. The microcontroller controls the speed of the stepper motor based on touch tones received from the mobile phone. Key hardware components include an AT89S52 microcontroller, DTMF decoder, ULN2003 driver, stepper motor, and power supply. The software used is Keil and the system is designed to rotate the stepper motor automatically when receiving a predefined command from a user's mobile phone.

1. A
TECHNICAL REPORT ON
SPEED CONTROL OF
STEPPER MOTOR USING
MOBILE

2. BATCH NAMES
1. S.SRINIVASA REDDY
2. B.RAMESH
3. J.KARTHIK
4. K. SRINU
GUIDE NAME:- V.NARESH KUMAR

3. ABSTRACT
 This project uses the wireless
communication, DTMF. To receive the
tones from the user mobile, we need a
mobile and dtmf receiver. This mobile will
be interfaced to the microcontroller
through dtmf receiver interface. A mobile
provides the communication interface

4. EMBEDDED SYSTEMS
 INTRODUCTION
 An embedded system is a special-purpose
computer system designed to perform one
or a few dedicated functions

5. HARDWARE TOOLS
 Hardware tools:
 Microcontroller AT89S52.
 DTMF decoder.
 ULN driver and the stepper motor
 Stepper motor

6. AT89C52 MICROCONTROLLER
 INTRODUCTION:-
 The AT89C52 is a low-power, high-
performance CMOS 8-bit microcomputer
with 4 Kbytes of Flash Programmable and
Erasable Read Only Memory (PEROM).

7. LOGIC SYMBOL

8. HARDWARE IMPLEMENTATION ULN
2003
 Introduction:
 The UTC (unisonic technologies co. ltd)
ULN 2003 is high-voltage, high-current
Darlington driver comprised of seven
NPN Darlington pairs

9. Features:
 (1) Output current (single output) 500mA
MAX.
 (2) High sustaining voltage output
50V MIN.
 (3) Output clamp diodes.
 (4) Inputs compatible with various
types of logic.
 (5) Dual In-Line Plastic Package or
Small-Outline IC Package

10. STEPPER MOTOR
 Introduction
A stepper motor is a brushless AC
synchronous electric motor that can divide
a full rotation into a large number of steps
 Stepper motor characteristics:
 As motor speed increases, torque
decreases.

11. Types of stepper motor:
 (1). Variable Reluctance motors
 (2). Permanent magnet
 (3). Hybrid Motors

12. Variable Reluctance motors:

13. Permanent magnet:

14. Hybrid Motors:

15. Power Supply:
 Power supply is a reference to a source of
electrical power.
 A device or system that supplies electrical
or other types of energy to an output load
or group of loads is called a power supply
unit
 This power supply section is required to
convert AC signal to DC signal and also to
reduce the amplitude of the signal.

16. Voltage Regulator :
A voltage regulator is an electrical
regulator designed to automatically
maintain a constant voltage level.

17. SOFTWARE REQUIREMENT
 Keil Software:

18. BLOCK DIAGRAM:

19. CONCLUSION
 Themain aim of this project is rotate the
stepper motor automatically as soon as it
receives a predefined command from the
user by mobile.

20. THANK
YOU