DESIGN AND CONSTRUCTION OF DTMF BASED HOME AUTOMATION

SYSTEM.

BY OGUNDELE, OLADIMEJI EMMANUEL

(2005/22070EE)

DEPARTMENT OF ELECTRICAL/COMPUTER ENGINEERING

OCTOBER 2010

DESIGN AND CONSTRUCTION OF DTMF BASED HOME AUTOMATION

SYSTEM.

BY: OGUNDELE, OLADIMEJI EMMANUEL

(2005/22070EE)

A PROJECT SUBMITTED TO THE DEPARTMENT OF ELECTRICAL/COMPUTER

ENGINEERING. FEDERAL UNIVERSITY OF TECHNOLOGY,

MINNA IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE AWARD

BACHELOR OF ENGINEERING (B.Eng) DEGREE

DECLARATION

I Oladimeji Ogundele Emmanuel declare that this work was done by me and has never

been presented elsewhere for the award of a degree. I also relinquish the copyright to

Federal University of technology, Minna.

Oladimeji Ogundele Emmanuel Mr. lAjiboye

(Name of supervisor)

~ .;i~.~~.~. (H~01" (Signature and date) (Signature and date)

Eng A.G Raji

('11 (Name ofR.O.D)

\Jl\r4.( {~. \ l· Q§;)\ 1\ (Signature and date) I '/

(Nmne of externru ex~{r~(r ~

(Signature and date)

iv

DEDICATION

This project is dedicated to the Almighty God, my parents and my siblings.

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ACKNOWLEDGEMENT

I would like to express sincere gratitude to God Almighty for the gift of life, my family for

their support and finally my supervisor; Mr. Ajiboye and Mr. Olawoye for their patience

and understanding. God bless you all.

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ABSTRACT

This project is a remote control system using DTMF (Dual tone multi-frequency) signals. This home automation project (system) employs the use of telephone lines. The system consists of two systems (the phones and the receiver system); the remote control system (the caller phone) and the phone monitoring system (the receiver system). Any phone could be the remote control system but the receiver system has a phone attached to it. The remote control system uses the dual tone multi-frequency signals to control the operation of the various appliances connected to the phone monitoring system. The devices connected to the phone monitoring system are controlled by predetermined commands. There also a provision for feedback to tell the human if the task was executed or not.

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TABLE OF CONTENTS

Dedication

Declaration

Acknowledgement

Abstract

List of figures

1.0 Chapter one: Introduction

1.1 Background

1.2 Scope of work

1.3 Methodology

1.4 Concept of dual tone multi-frequency

1.5 Statement of problem

1.6 Sources of information

2.0 Chapter two: Literature review

2.1 Development of remote control appliances

3.0 Chapter three: Design objectives

3.1 Design consideration

3.2 Design calculations

3.2.1 Power supply

3.2.2 Drive circuitry

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III

IV

V

VI

Vll

1

1

1

1

2

3

3

5

5

10

10

11

11

16

3.2.2.1 Crystal oscillator 16

3.2.2.2 Steering circuit 17

3.2.2.3 Microcontroller 18

3.3 Working operation of the interface device 19

3.4 Software design 20

C.s [ 4.0 Chapter four: Testing and Discussion 24

4.1 Power supply testing and discussion 24

4.2 Main circuitry testing and implementation 25

4.3 Soldering 25

4.4 Casing construction and assembly 26

4.4.1 Physical factors 26

4.4.2 Environmental factors 26

4.5 System reliability and maintenance 27

4.6 Applications 28

4.7 Problems encountered 28

5.0 Chapter five: Conclusion 29

5.1 Summary of work done 29

5.2 Conclusion 29

5.3 Recommendation 30

Reference 31

Appendix 33

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List of figures

Fig 3.1 A typical DC power supply block diagram.

Fig 3.2 Voltage output at the transformer; rectifier and filter .

Fig 3.3 Load resistance of relays in the circuit.

Fig 3.4 Load resistance of the decoder and microcontroller.

Fig 3.5 A part of the drive circuit; the tone decoder.

Fig 3.6 The steering circuit of the decoder.

Fig 3.7 Block diagram description of the cell phone remote control.

Fig 3.8 A flowchart description of the microcontroller program. ' .

Fig 3.9 The circuit diagram of the device.

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