AUTOMATIC LIGHTING SYSTEM FOR CHILDREN

Cheong Yew Wai

BEKM

APRIL 2009

i

“I hereby declared that I have read through this report and found that it has

comply the partial fulfillment for awarding the degree of Bachelor of Electrical Engineering

(Mechatronic)”

Signature :

Supervisor’s name : Pn. Ainain Nur binti Hanafi

Date : 22 April 2009

ii

AUTOMATIC LIGHTING SYSTEM FOR CHILDREN

CHEONG YEW WAI

A report submitted in partial fulfillment of requirements for the degree

of Bachelor of Electrical Engineering (Mechatronic)

Faculty of Electrical Engineering

UNIVERSITI TEKNIKAL MALAYSIA MELAKA

APRIL 2009

iii

I hereby declared that this report “Automatic Lighting System for Children” is a result of my

own work research except as cited in the references.

Signature :

Name : CHEONG YEW WAI

Date : 22 APRIL 2009

iv

ACKNOWLEDGEMENT

In preparing this report, i have go through various of resources such as publish materials,

journal, and contact with a lot of peoples. First of all, I would like to express my gratitude to

my project's supervisor, Puan Ainain Nur Hanafi for her guidance, helps, and most

importantly is her morale support to me. Without her, I am still in nowhere for this project.

She always giving me feedback during the time I need it. I am glad that I have a kind and

responsible supervisor for this project.

I would like to say thanks to all others contributor for the information regarding to my

final year report. These included my classmate especially Nicholas Su Shyn Sern and Shiva

Raj. Without them, I am not able to develop my ideas in preparing for this report and also for

the project. Not only that, I will not also forget the things you guys advise me and your morale

support through all years since we know each others.

For those who I am not mentioning which includes feedbacks from Internet surfers or

users, technical support from lab assistance, indirect materials and resources from previous

and this semester lecturers, research and thesis done by previous students not only from inside

but also from outside the university and also other courses friends. Thank you for all your

resources and materials which helps me in complete this project and also the report. Thank

you once again for all the indirect and direct people who involved in this project.

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ABSTRACT

Lighting is very important kind of generated energy to allow people clearly doing its jobs.

Lighting includes artificial light such as incandescent light and natural light which comes from

the sun. Artificial light can be normally obtained inside a building or under the roof. Not only

that, street also have artificial light for pedestrian and drivers at night time. For the artificial

light, normally a manual switch is available for each lighting system. In this report, priority or

precedence is focusing on how this artificial light can helps children at night. This artificial

light project is capable of helping and guiding children by automatic on and off during

necessary time, flexible to be used by everyone and everywhere and possess appropriate

illuminance which not too disturbing when use. Children normally confront with high

placement of the manual switch which is a difficult for them to reach. An approach to help

these children, the benefits and special features of PIC and PIR will be harness and utilize to

solve the problem. At the completion of the project, the children greatly having and gaining

advantages through a flexible device to guide them in doing their jobs.

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ABSTRAK

Cahaya merupakan sejenis bentuk tenaga yang dijanakan untuk membantu manusia untuk

melakukan atau membuat sesuatu kerja. Cahaya terdiri daripada cahaya buatan seperti lampu

dan cahaya semulajadi iaitu datangnya dari cahaya matahari. Cahaya buatan biasanya terdapat

di dalam bangunan atau tempat yang berteduh. Selain daripada itu, cahaya buatan juga

terdapat di jalan-jalan untuk membantu pemandu dan juga orang ramai pada waktu malam.

Untuk cahaya buatan, biasanya terdapat suis dalam setiap sistem cahaya buatan. Projek ini

memberi keutamaan dalam membantu kanak-kanak pada waktu malam. Projek cahaya buatan

ini dapat membantu dan memberi petunjuk kepada kanak-kanak dengan adanya sumber

cahaya automatik apabila diperlukan. Malahan ia fleksibel boleh digunakan oleh sesiapa

sahaja dan dimana-mana tempat, tidak terlalu malar dan memberikan kecerahan yang sesuai

supaya tidak menggangu penglihatan apabila digunakan. Kanak-kanak biasanya menghadapi

masalah dalam mencapai suis lampu kerana lokasinya yang tinggi. Dalam pendekatan ini,

kebaikan dan keistimewaan fungsi yang terdapat pada PIC dan PIR akan dicungkil untuk

menyelesaikan masalah ini. Pada akhir projek ini, kanak-kanak dapat memanfaatkan hasil

daripada alat fleksibel ini dalam membantu mereka membuat kerja mereka.

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TABLES OF CONTENTS

CHAPTER TITLE PAGE

SUPERVISOR’S ENDORSEMENT i

TITLE PAGE ii

DECLARATION PAGE iii

ACKNOWLEDGEMENT iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES x

LIST OF FIGURES xi

LIST OF ABBREVIATIONS AND SYMBOLS xiii

LIST OF APPENDICES xv

1 INTRODUCTION 1

1.1 Introduction 1

1.2 Problem Statement 1

1.3 Project objectives 2

1.4 Project scopes 2

2 LITERATURE REVIEW AND PROJECT BACKGROUND 4

2.1 Introduction 4

2.2 Power Supply 4

2.3 Motion Detector 5

2.3.1 Infrared Radiation 5

2.3.2 PIR Sensor 6

2.3.3 Fresnel Lens 8

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2.3.4 Frequency Range 9

2.3.5 Active Filter and Operational Amplifier 10

2.3.6 Amplification and Filtering Circuit 13

2.3.7 Disturbances and Comparator Circuit 15

2.4 Light Detector 16

2.5 Programmable Interface Controller 17

2.5.1 Analog to Digital Converter 18

2.5.2 Programming and PIC Programmer 20

2.6 Light Generator 21

3 MATERIALS AND METHODS 22

3.1 Introduction 22

3.2 Design System Circuit Diagram 23

3.3 Software Simulation 23

3.3.1 Pspice software 24

3.3.2 MikroC Compiler for PIC Software 25

3.3.3 Proteus Software 26

3.3.4 PIC Programmer 27

3.4 Hardware Implementation 28

3.4.1 Motion Sensor Hardware 28

3.4.2 PIC Programmer Hardware 29

4 RESULTS 30

4.1 Result on Hardware 30

4.1.1 Motion Sensor 30

4.1.2 PIC Programmer 32

4.2 Results on software 33

4.2.1 C programming 33

4.2.2 PSpice Simulation 36

4.2.3 Proteus Simulation 38

4.2.3.1 Proteus simulations when LDR > 39

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2.91V

4.2.3.2 Proteus simulations when LDR

2.91V

41

4.3 Results on completed motion sensor design 42

4.3.1 Result on the amplification 42

4.3.2 Result on the output 44

4.3.3 Result on the range of detection 44

5 DISCUSSION ON RESULTS 45

5.1 Output Signal 45

5.2 The Design 46

5.3 Sensing Distance 46

6 SUMMARY AND CONCLUSION 47

6.1 Summary of the entire work 47

6.2 Strength and weaknesses of the design 47

6.2.1 Strength of the design 48

6.2.2 Weakness of the design 48

6.3 Recommendation for future work 48

REFERENCES 50

APPENDICES 51

x

LIST OF TABLES

TABLE TITLE PAGE

2.1 Ideal Op Amp parameters 10

4.1 C programming code of the design along with the explanation 33

4.2 Expected results and simulation results of the design 39

4.3 Measured results before and after the amplification process 43

4.4 Range of detection 44

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LIST OF FIGURES

FIGURE TITLE PAGE

2.1 Design block diagram 4

2.2 Typical circuit of voltage regulator 5

2.3 Electromagnetic spectrum 6

2.4 PIR dual element construction 7

2.5 Operation of PIR sensor when motion detected 7

2.6 Plano Convex lens and Fresnel lens 8

2.7 Arrangement of Fresnel lens and the PIR sensor 8

2.8 Ideal Op Amp 10

2.9 Inverting op amp 10

2.10 Non inverting Op Amp 11

2.11 Bandpass filter circuit 12

2.12 Bandpass frequency response curve 12

2.13 Capacitor behaviour 13

2.14 First and Second stage of amplification circuit diagram 13

2.15 Alternative of first stage circuit 14

2.16 Amplified signal with noise disturbances and air movements 15

2.17 Input and output signal of a comparator circuit 16

2.18 LDR and its symbol 16

2.19 Voltage divider circuit and plot of resistance verses light intensity

of LDR

17

2.20 Pins diagram of PIC16f876A microcontroller 18

2.21 Conversion signal from analog to digital 19

2.22 PGA build in analog input configuration 19

2.23 Conventional circuit for amplification 20

2.24 Window of microC compiler for PIC 20

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2.25 Universal programmer 21

3.1 Flow chart of the project 22

3.2 Design system circuit diagram 23

3.3 Assembled circuit and the parameters 24

3.4 AC analysis setup 24

3.5 AC parameters setting 25

3.6 Simulation result 25

3.7 Building the written program 26

3.8 Design circuit 27

3.9 WinPic800 programmer software 27

3.10 Rough sketch of the design 28

3.11 Circuit diagram of the PIC programmer 29

4.1 Front view 30

4.2 Side view 31

4.3 Back interior view 31

4.4 Side exploded view 31

4.5 Side exploded view 2 32

4.6 PIC programmer 32

4.7 Flow chart of the program 35

4.8 PIR output before and after amplification and the respective

bandpass frequency

36

4.9 Disturbances amplification and bandpass filter signal waveform 36

4.10 Simulation when PIR > 3.01V 39

4.11 Simulation when PIR < 1.86V 40

4.12 Simulation when 1.86V PIR 3.01V 40

4.13 Simulation when PIR > 3.01V 41

4.14 Simulation when PIR < 1.86V 41

4.15 Simulation when 1.86V PIR 3.01V 42

xiii

LIST OF ABBREVIATIONS AND SYMBOLS

A - Ampere

AC - Alternating Current

ADC - Analog Digital Converter

C - Capacitor

DC - Direct Current

FET - Field Effect Transistor

Hz - Hertz

IR - Infrared

In - Input current

L - Working distance

LDR - Light Dependent Resistor

Op Amp - Operational amplifier

PIC - Programmable Interface Controller

PIR - Passive Infrared or Pyroelectric Infrared

R - Resistor

Rf - Feedback resistor

Rg - Input resistor

V - Volt

Vb - Velocity

Vcc - Power supply voltage

Vin - Input voltage

Vos - Input offset voltage

Vout - Output voltage

Zin - Input impedance

Zout - Output inpedence

a - Gain

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f - Frequency

fb - Focal length

mA - mili Ampere

mm - milimeter

m/s - meter/second

nF - nano Farad

nm - nanometer

uF - micro Farad

um - micrometer

xv

LIST OF APPENDICES

APPENDIX TITLE

A PIR LHi 968 sensor datasheet

B TS2937 voltage regulator datasheet

C Frequency verses velocity with various focal length

D PIC16F876A datasheet

E Operational Amplifier datasheet

CHAPTER 1

INTRODUCTION

1.1 Introduction

Everyday human activities are leads by light inconsiderate whether during daylight or

night time. Without the light as our guidance, human cannot complete their desire tasks such

as finding the route to their destination. Ancient human used firewood as their tool to guide

them and then slowly improve. Nowadays with latest and innovative creation human now

depends alternatively on artificial lighting system whether within a covered building or an

open areas. Few examples such as pilot landing the airplane by following and using guidance

from the lighting system on the route track, human staying within a building can see clearly

the path to their destination and do other activities even though is daylight, and vehicle using

artificial lighting system to see the route at night when traveling. Without the light, many

disaster and unwanted events may be happened such as car crash accident on the route at night,

pedestrian suffer from hurt when they hit or kick or bang into obstacles, and most apparent is

human have to live in the dark.

1.2 Problem Statement

Conventional lighting system normally designed for adults and youngster to reach for the

light. Children especially encounter problems to reach and turn on the light. This is because

the location of the switch normally mounted on a place where it is easy for youngsters and

adults to turn on but not for children. Some parents will taking an alternative way by

modifying the switch such as changing the whole wall switch with a switch where it have a

2

long stick for children to pull or adding another switch parallel with the switch so that

everyone can turn on the light.

Conventional lighting system has to be manually operated to turn on the light. At the night

time, peoples have to search the location of the switch in the dark environment to turn on the

light. Some peoples will get hurts and frustrated when searching the switch in the night time or

in the dark environment.

At outside from a building or open area, light not usually available everywhere. With

invention of dc power supplies such as battery, most peoples able to utilize this technology to

power up their portable device. By using this portable battery, a lighting system can be carry

all over the world without interruption such as have to fix at one position like ac lighting. In

other way, the design is very flexible to be used everywhere and anyone.

1.3 Project Objectives

The objectives of this project are to design a portable lighting system with automatic

lighting capability when it senses a motion from human when passing through the within

sensing areas. The design also capable to saving electricity because it will automatically turn

off after certain of time when human detection are no longer detected within sensing areas. By

using this design, human lifestyle can be improve because it is no longer required to depends

on the conventional manual switch and a new feature is added in that is the portability lighting

system capability which allow to carry and install or place at a desire place and location. This

design is focusing on helping children when no light present especially at night time or in dark

area to leads them to their destination or allow then to do their activities.

1.4 Project Scopes

The scopes of this project are to design a portable device mainly to detect presence of

3

the children, it is running dc power supply, the design detection range is in low range, it is only

used in indoor and the output is only light. Passive Infrared sensor (PIR) will be used as a

motion sensor detector. On and off control of the lighting is depends on the light dependent

sensor (LDR) and battery voltage 9 volt is being used in this project. Also this project used

microcontroller PIC 16f8776a as the embedded controller and the language for the

programming part is C language.

CHAPTER 2

LITERATURE REVIEW AND PROJECT BACKGROUND

2.1 Introduction

The overall design objective is to react with children motion and then turn on the light.

This chapter will cover the discussion on the block diagram as shown in the Figure 2.1.

Figure 2.1: Design block diagram

2.2 Power Supply

The crucial part of any devices in the world is the power supply. Without the power supply,

every device cannot operate at its behaviors. In the design, the power supply is comes from 9

volt battery. The supply voltage is then regulated to 5 volt which suit to the design operation.

In this design, the voltage regulator has been use and is model name was called TS2937. This

regulator will produce output current up to 500mA and it possess low drop out voltage at 0.6

volt which is the crucial parameter have to be consider when designing any portable

application devices. The reason that voltage drop out is important is shown in the Figure 2.2.

POWER

SUPPLY

MOTION

DETECTOR

LIGHT

DETECTOR

OPERATIONAL

AMPLIFIER AND

FILTERS

PIC LIGHT

GENERATOR

5

Figure 2.2: Typical circuit of voltage regulator

As seen from the Figure 2.2 if the voltage is less than 7 volt, the output voltage will decrease

with respect to the input voltage. The explanation on the input and output capacitor is covered

in the TS2937 data sheet along with others related information that have been attached in the

Appendix B.

2.3 Motion Detector

Motion sensor in this design is using Pyroelectric Infrared sensor or Passive Infrared

sensor or PIR in brief term. To apply motion sensor in the design, several parameter need to be

considered and understand which are infrared radiation, PIR construction, Fresnel lens,

frequency range, amplification circuit, disturbances and comparator circuit. All these

parameter need to be considered in order to design a motion detector. The detail of the PIR

sensor used in the design can be referring in the Appendix A.

2.3.1 Infrared Radiation [1]

To understand how infrared detector works, it is important to understand electromagnetic

spectrum. Visible emission is the light that all human can see and it is only a small portion out

of total of light spectrum. The wavelength of the visible spectrum is range from 400nm to

800nm. The infrared spectrum is range from 800nm to 1mm which is longer than visible light.

6

Object that generate heat, also generate infrared radiation and those objects include

animals and the human body, whose radiation is strongest at 9.4um. Figure 2.3 shows the

electromagnetic spectrum:

Figure 2.3: Electromagnetic spectrum

From the Figure 2.3, it is shown that human body emits Infrared radiation at approximately

10um. To detect this signal, a transducer is required to convert the infrared signal to a

detectable form with conventional circuitry.

2.3.2 PIR Sensor [2][3]

PIR sensor is made from a crystalline material that generates a surface electric charge

when exposed to heat in the form of infrared radiation. PIR sensor are passive device, it do not

emit or radiate any energy or beam. When the amount of radiation striking the crystal changes,

the amount of charge also changes and can then be measured with a sensitive FET device built

into the sensor. The sensor elements are sensitive to radiation over a wide range so a filter

window is added to the TO5 package to limit incoming radiation to the 8um to 14um range

which is the most sensitive to human body radiation. Figure 2.4 shows the PIR internal

construction.

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Figure 2.4: PIR dual element construction

The external resistor as shown in Figure 2.4 is function as to convert the FET current to a

voltage. The output voltage is a function of the amount infrared radiation sensed at the input.

Unfortunately the output is also affected by vibration, radio interference and sunlight. Motion

sensor can be improved by using dual element. The sensing elements are connected such that

one subtracts from the other. The arrangement causes any signal common to both elements to

be canceled. A body passing in front of the sensor activates first one and then the other

element while vibration and the other background signals, affect both elements simultaneously

and are cancelled. Figure 2.5 shows the operation of the sensor when a human body is passing

in front of the sensor.

Figure 2.5: Operation of PIR sensor when motion detected

FET IR filter

8

2.3.3 Fresnel Lens [3]

To enable detection few feet away, Fresnel lens is required. Beside that the PIR sensor

itself is inefficient if it does not have a lens to focus the radiation. A Fresnel lens is a Plano

Convex lens that has been collapsed on it to form a flat lens that retains its optical

characteristics but is much smaller in thickness and therefore has less absorption losses. Figure

2.6 shows the Plano Convex lens and Fresnel lens.

Figure 2.6: Plano Convex lens and Fresnel lens

Fresnel lens is normally made of an infrared transmitting material that has IR transmission

range of 8um to 14um that is most sensitive to human body radiation. It is designed to have its

grooves facing the IR sensing element so that a smooth surface is presented to the subject side

of the lens which is normally the outside of an enclosure that houses the sensor. Figure 2.7

shows the arrangement of the Fresnel lens with the PIR sensor.

Figure 2.7: Arrangement of Fresnel lens and the PIR sensor