galant project

7/31/2019 Galant Project

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CHAPTER ONE: INTRODUCTION

1.0 BACKGROUND

The society we live in today is one of convenience, many things we do

involve using automated processes in one form or another. For example, when

we are in shopping malls, we can take escalators to different floors, when we

want to communicate, we can pick up our cell phones and talk to persons

thousands of kilometres away. Modern marvels such as these have changed our

lives.

Since time immemorial, man had maintained a stance of creativity and

development of innovations that made it possible for the emergence of tenable

solutions whenever confronted with inconveniences, thus necessity is the

mother of invention.

The application of electronics and mechanical devices to the world

around us is nearly limitless. Since the advent of semiconductor devices till

date, the world has seen electronics become a major influence in every aspect of

our daily life. It is virtually impossible to do daily tasks without relying on

electronics and automation.

This project work is based on the application of microcontroller with its

ancillary components and mechanics. Almost all areas of technology have

started taking the advantage of the inexpensive computer control that the

microprocessor can provide. The automatic door opener with motor driver

described here automates the entrances to residential and public buildings such

as banks, shopping malls, hotels, company offices, airports and packing lots to

residential homes, organizations, automobile terminus and public car parks. It

consists of sensors placed at a close proximity to the entrance and exit which

senses an interruption caused by a person or any opaque object at the entrance


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and exit, and the microcontroller which monitors the state of the sensors. The

microcontroller in turn sends a signal to the motor which in accordance with the

program opens and closes the door via motor driver.

1.1 PROBLEM STATEMENT

The inconvenience experienced in trying to open or close entrances and

exits doors respectively by visitors or strangers entering into large buildings

such as big shopping malls, hotels, airports, large offices and some residential

homes, carrying items bought from shopping malls for example, or those

carrying their luggage to the airports as well as the unfortunate disposition of

the elderly or physically challenged- those who cannot on their own open

entrance doors but would depend on helping hands, are the problems that

necessitated this research work.

A need for the automation of entrance and exit doors is thus needed, and

it is the intention of this research work to design an automatic door with a

display that is based on a microcontroller.

1.2 OBJECTIVE

The objective of this study is to design and construct a microcontroller

based automatic door opener with a counter and LCD display for use in public

buildings such as company offices, banks, shopping malls and some residential

homes so as to provide convenience, easy access and in order to monitor the

number of persons in the building.


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1.3 SCOPE

This project work is the design and construction of a microcontroller

based automatic door that opens and closes upon sensing any person

approaching the sensors close to the door, with an LCD display that displays a

count not exceeding 255 persons entering or leaving the building.

1.4 SIGNIFICANCE

Inhabitants of and visitors to public and residential buildings, tourism and

entertainment venues like airports and hotels, would benefit from this study as it

checks the frequent inconvenience experienced in entrance and exit by strangers

or visitors.

The research work would be beneficial to Electrical and Electronics

Engineering students across higher institutions as it would go a long way to

exposing them to the application of microcontrollers for development of simple

and complex automation.

1.5 ORGANIZATION

This project report is made up of five chapters and what each chapter

handles is stated below;

I) Chapter one deals with the general introduction to the project work; it

consists of the background, problem statement, objective, scope and

significance of the work.

II) Chapter two handles the literature review; information on previous

work relevant to the topic.


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III) Chapter three deals with the design and construction procedures,

details of all calculations and working drawings and design

considerations for the choice of component values.

IV) Chapter four covers the performance and cost evaluation; it contains

the results and findings of the research work, and the respective cost

of all components used.

V) Chapter five handles the summary, conclusions and recommendations

for further work.


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CHAPTER TWO: LITERATURE REVIEW

2.0 INTRODUCTION

The need for automatic doors has been on the increase in recent times.

The system described here incorporates the use of microcontroller as a

controller in achieving the purpose of this project. As affirmed by Shoewu and

Baruwa [1], the microcontroller has revolutionalized the electronics industry

and has had a remarkable impact on many aspects of our lives. Almost all areas

of technology have started taking advantage of the inexpensive computer

control that microprocessor can provide. Some typical applications include

electronic games, CD players, automatic braking systems, industrial process

controls, electronic measuring instruments, automobile emission controls,

microwave ovens, traffic controllers, and a rapidly growing number of new

products.

The automatic door described here automates the entrances to public

buildings such as banks, shopping malls, office buildings, airports, residential

homes, automobile terminus, and public car parks. It uses the microcontroller

convenience to avoid the stress of manually opening and closing the entrance

doors. The technology used eliminates door monitoring and manning by human

beings. The door uses the state-of-the-art entry system, the doors have to

perform gyrations-open, auto-reverse, stop, fully close and fully stop.

The automatic door is not a security device and should not be construed

as one. It provides a convenient access and intelligent feature that makes it

distinct from all other door which brings it so close to security device.


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2.1 REVIEW OF AUTOMATIC DOORS

The automatic door operation is accomplished when the open or initiate

command is transmitted from the activation device to the control box. A wide

variety of devices can be used to activate the doors including wall switches,

motion or proximity sensors, infrared beams, or any device that switches using

dry contents. Krutz [2] asserted that a microcontroller based control board

controls the hold open time and functionality of the doors. Hold open times can

be set 1-99 seconds by means of the control board and opening times can be

adjusted from 1.5 to 5 seconds by changing air regulator pressure and air flow

controls.

McGlen [3] said that series operator can be easily mounted to any

conventional door frame header and the face of the door. Easy to use templates

and an extensive installation and owners manual are included with the units

allowing for simple installation.

Private door openers [4] revealed that the control box is microcontroller

based to insure maximum reliability and flexibility for the end user. The system

has been designed to be easy to set up and operate. The control unit is design to

be connected to a constant power source of 220V, 60Hz, which powers the

control box and a wide variety of activation devices with 24AC power. The

control box can be mounted up to 25 feet away from the operator. The only

connection between the control box and the operators are two flexible

diameter air lines. Air supply to the control box is accomplished through a

single air line, if multiple sets of operators are connected to a single control

box, a larger air supply line to the control box may be required.


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2.2 REVIEW OF SENSORS

LIGHT DEPENDENT RESISTORS (LDR)

Floyd, [5] defines light dependent resistor (LDR) as a device which has

resistance which varies according to the intensity of light falling on its surface.

He further explained that light dependent resistors are vital component in any

electric circuit which is to be turned on or off automatically according to the

level of ambient light-for example, solar powered garden lights, and night

security light.

Fig. 2.1: A typical light dependent resistor.

Neal [6] interfaced a simple LDR sensor circuit to a microcontroller to

control a light/dark detector. According to him, there are two basic circuits

using the LDR, the first is activated by darkness, the second is activated by

light. The two circuits are very similar and just require an LDR, some standard

resistors, a variable resistor and any small signal transistor.

According to Floyd [5], LDRS or light dependent resistors are very

useful especially in light/dark sensor circuits. Normally the resistance of an

LDR is very high, sometimes as high as 1M, but when they are illuminated

with light resistance drops dramatically.

When the light level is low the resistance of the LDR is high. This

prevents current from flowing to the base of the transistors. Consequently thelight emitting diode (LED) does not light. However, when light shines onto the


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LDR its resistance falls and current flows into the base of the first transistors

and then the second transistor, the LED lights.

The present resistor can be turned up or down to increase or decrease

resistance, in this way it can make the circuit more or less sensitive.

Vo ( )Vin

The LDR was used to design and construct a device that would be of use

to persons who are in the habit of falling asleep while watching or listening to

music. The scope of the work ranges from the conceptualization of the idea and

theories behind the operation of the device to the stage of packaging the design.

The unit provides automatic disconnection of the appliances from the

alternating current (AC) main supply upon the expiration of a pre-set time delay

period. The system works by detecting a transition from light to darkness in a

room. This triggers the device into a time-out mode. During the time delay

period, the appliances e.g. compact disk player is connected to main supply.

Disconnection occurs after the pre-set time delay period elapses.

A key feature of this device is that its operation is light dependent, that is,

the device is activated only when it is powered ON in the absence of ambient

light or in a sufficiently dark environment making it a light dependent

automatic-off timer for electrical appliances. The light dependent automatic-off

timer uses a light dependent resistor (LDR) as its light sensor.

INFRARED SENSOR

Infrared radiation is part of the electromagnetic spectrum which includes

radio waves, microwaves, visible light, ultraviolet light, as well as gamma and

x-rays.


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The infrared range falls between the visible portion of the spectrum and

radio waves. Infrared wavelengths are usually expressed in microns, with the

infrared spectrum extending from 1.7 to 1000 temperature measurement.

Using advanced optic systems and detectors, non-contact infrared

thermometers can focus on nearly any portion or portions of the 0.7-14 micron

band. Because every object emits an optimum amount of infrared energy at a

specific point along the infrared band, each process may require unique sensor

models with specific optics and detectors types. For example, a sensor with a

narrow spectral range centred at 3.43 macrons is optimized for measuring the

surface temperature of polyethylene and related materials. A sensor set up for 5

microns is used to measure glass surfaces.

As explained, the intensity of object emitting infrared energy varies in

proportion to its temperature. It is the emitted energy, measured as the targets

emissivity that indicates an objects temperature. Emissivity is a term used to

quantify the energyemitting characteristics of different materials and surfaces.

Infrared sensors have adjustable emissivity settings usually from 0.1 to 10,

which allow accurate temperature measurement of several surface types.

The emitted energy comes from an object and reaches the infrared sensor

through its optical system, which focuses the energy onto one or more

photosensitive detectors, the detector then convert the infrared energy into an

electrical signal ,which is in turn convert into a temperature value based on

sensors calibrations equation and the targets emissivity. This temperature

value can be displayed on the sensor or in the case of the smart sensor,

converted to a digital output and displayed on computer terminal.


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2.3 REVIEW OF COMPUTER MEMORIES

The purpose of electronic memories is the same as that of human

memory-to retain information so that it can be used at a later time, Tokheim [7].

Although human memory is able to store a wide variety of items, such as

names, languages, images of scenes, scent, digital electronic memory is limited

by being able to remember only sequences of zeros and ones or highs and lows.

Much of the effort invested in computer science at the present time is devoted

toward finding efficient ways to store and retrieve information about languages,

images and perhaps even scent in digital memories.

The development of electronic memories or electronic storage elements

has been an integral part of the development of computers, as a result, the

language used to describe memories is the language of computer architecture

and computer science; the converse is also true. In fact, early computers were

called stored program devices, or stored program calculating machines,

indicating that at least in the beginning, one of the most important features of

computer was the memory.

A wide variety of memories or storage elements have been used within

the relatively short computer era. The earliest computers used relays and

punched paper tapes memories. Other early elements included acoustic delay

lines (an electromechanical analogue of a shift register) and magnetic drums.

Since then punched cards, magnetic tapes, magnetic disks of many types and

magnetic cores have been used.

In the last decade, integrated solid state memories have come to dominate

the computer memory market.


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2.4 REVIEW OF THE ATMEL AT89S52 MICROCONTROLLER

According to Mazidi [8], the AVR Atmel Corporation, in 1981

introduced an 8-bit microcontroller called the AT89S52.This microcontroller

had 256 bytes of RAM,8K bytes of on-chip ROM, three timers, one serial port

and four ports (each 8-bit wide) all on a single chip. At the time, it was also

referred to as a system on a chip. The AT89S52 is an 8-bit processor,

meaning that the CPU can work on only 8 bits of data at time. Data larger than 8

bits has to be broken into bits pieces and be processed by the CPU. The

AT89S52 has a total of four input and output ports, each 8 bits wide. Although

the AT89S52 can have a maximum of 64k bytes of on-chip ROM, many

manufacturers have put only 4k bytes on the chip.

The AT89S52 became widely popular after Atmel allowed other

manufacturers to make and market any flavour of the AT89S52, they are

pleased with the condition that they remain code-compatible with the

AT89S52.This has led to many versions of the AT89S52 with different speeds

and amounts of on-chip ROM marketed by more than half a dozen

manufacturers. It is important to note that although there are different flavours

of the AT89S52 in terms of speed and amount of on-chip ROM, they are all

compatible with the original AT89S52 as far as the instructions are concerned.

This means that if you write your program for one, it will run on any one of

them regardless of the manufacturer.

FEATURE QUANTITY

ROM 8K bytes


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RAM 256 bytes

Timer 3

I/O pins 32

Serial port 2

Interrupt

Sources

8

Table 2.1: Features of the AT89S52 microcontroller.

2.5 REVIEW OF DISPLAYS

Shoewu and Baruwa [1] used a 7-segment configuration to form the

decimal characters 0 through 9 and the hex characters A through F. The displayunit comprised of the following; Z80 PIO, BCD-to-7-Segment Decoder/Driver

and a7-Segment display.

The Z80 PIO used in the display unit provides two 8-bit I/O ports, which

have been programmed as output ports. The output of the PIO cannot be fed

directly to the 7-segment display; therefore, it needs a driver. The unit sends

signals to the driver each time a vehicle crosses the gate. A BCD-to-7-Segment

Decoder/Driver is used to take a four-bit BCD input and provide the outputs

that will pass through the appropriate segments to display the decimal digits.

Figure 2.4 shows the BCD-to-7-Segment Decoder/Driver (74LS47) being used

to drive a 7-Segment common anode LED readout. Each segment consists of

one or two LEDs. The anodes of the LEDs are all tied to Vcc (+5V). The


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cathodes of the LEDs are connected through currentlimiting resistors to the

appropriate outputs of the decoder/driver.

The decoder/driver has active-LOW outputs, which are open-collector driver

transistors that can sink a fairly large current. This is because LED readouts

may require 10 to 40mA per segment, depending on their type and size.

The display unit is used to show in decimal values, the number of vehicles that

passed through the entrance gate (number of vehicles coming in) and the

number of vehicles going out through the exit gate. The difference between the

two gives the number of vehicles in the facility at any time. This serves as acounter.

The system is designed in such a way that it monitors the space available in the

park.

Fig. 2.2: Display unit.


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2.6 REVIEW OF DOOR CONTROL

Shoewu and Baruwa [1], in an endeavour to design and construct a

microprocessor based automatic gate, employed the use of the following

devices to achieve automatic gate control;

- PNP and NPN transistors

- Diode

- Motor

The PNP and NPN transistors are arranged in such a way that a pair (PNP

and NPN) controls the opening of the gate through the motor and the other pair

reverse the polarity of the motor by rotating it in the opposite direction to close

the gate. There is a time interval of 10 seconds between the opening and the

closing of the gate. The arrangement of the diode serves to protect the

transistors from reverse bias polarity and the resistor serve to improve

switching time.

The motor is used to control the opening and closing of gate, the electric (DC)

motor used is one that has the ability to rotate in both directions simply by

reversing the polarity.


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Fig. 2.3: Door control circuit.

The researcher after embarking on diligent study of various literatures

was informed about the attempt by several individuals, and groups of

individuals to develop an automatic door opener. It reveals the distinct

difficulties and problems encountered by them. One of the intriguing efforts is

the one made by two indigenes- Shoewu and Baruwa specifically on the

software and the motor control system. Considerable setbacks were noticed,

besides there were limitations on the sensor units being triggered erratically, the

researcher wishes to work towards overcoming such limitations.

\

S1

DC_MOTOR_ARMATURE

A

D11N4007GP

D21N4007GP

D31N4007GP

D41N4007GP

Q1

BJT_NPN_VIRTUAL

Q2

BJT_NPN_VIRTUAL

Q3

BJT_NPN_VIRTUAL

Q4

BJT_NPN_VIRTUAL

R1

1K

R2

1K

R3

1K

R4

1K

1

24

567 8

9

12

10 11


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CHAPTER THREE: DESIGN AND CONSTRUCTION

PROCEDURE

3.0 SYSTEM DESCRIPTION

From fig. 3.1 shown below, once the system is powered on, the infrared

transmitter continuously transmits infrared light at a frequency of 38KHz which

can be received by the infrared receiver. The microcontroller monitors the state

of the receiver output and then enables the motor driver to open or close the

door when there is a change in the state of the receiver (from low-high or high-

low); the microcontroller also registers and increments the count as persons

enter or leave through the door and sends the data to be displayed on the LCD

display. A complete circuit diagram of the system and a snapshot of the circuit

is shown in the appendix.

Certain specifications, parameters and methods of implementation must

be considered in system design and construction in order to give the expected

result. The various data on the components used in the design of the study were

obtained from datasheets and textbooks. They provided the electrical

characteristics (maximum and minimum voltage, current and power ratings of

electrical components) which served as a guide in properly utilizing the

components in the design.

The implementation of the design involves segmenting the overall systemdesign into modules/units, which are individually designed and tested before the

integration of the various subsystems. The system design is divided into;

I) Hardware design consisting of:

- Power Supply Unit

- Infrared Sensor Unit


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- Door Control Unit

- Display Unit

- CPU Module

II) Software

MOTOR

Fig. 3.1: Block diagram of the system.

INFRARED

RECEIVER

INFRARED

TRANSMI-

TTER

MOTOR

DRIVER

AT89S52

MICRO-

CONTRO-

LLER

POWER

SUPPLY

SWITCHLCD

DISPLAY


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3.1 POWER SUPPLY UNIT

The microcontroller based system design has to be activated with a clean

power supply of good regulation characteristics. A transient on the power line

could send the microcontroller wandering, resulting in system failure. The

circuit operates on a 5V voltage and as a result, the power supply unit design is

5V DC and is not affected by variations in the AC voltage serving as input to

the transformer. The components used as shown in fig. 3.2 are explained below:

Fig. 3.2: Power supply unit.

3.11 TRANSFORMER

In order to achieve an input voltage for the regulator that falls within the

range of the difference between input and output of the regulator, a transformer

with a secondary voltage of 8.5V was rewound so as to obtain a peak voltage of

12V as explained below;

Input voltageOutput voltage of regulator = 47 V

With an input voltage of 12V and an output voltage of 5V,

125 = 7V, which falls within the range.

The input voltage into the regulator is the output voltage of the capacitor, andthe output voltage of the capacitor = Vp = 12V


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Where Vp = Peak voltage

Vp = Vrms 3.1

Vrms =

Vrms =

= 8.5V

Vrms is the secondary voltage of the transformer and thus the transformer

equation is used to get the number of turns in the secondary side of the

transformer as shown;

E = 4.44fm N . 3.2

m = Bm A . 3.3

Where,

E = transformer secondary voltage

f = frequency of the AC source

m = maximum flux

N = number of secondary turns

Bm = maximum flux density

A = area of the core

E = 8.5V, f = 50Hz, Bm = 1.15 wb/m2

for sine wave

A = l b

From measurements of the transformer core,


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l = 2.9cm, and

b = 2.2cm

A = 2.9 2.2 = 0.029 0.022

= 6.38 10 4 m2

From, E = 4.44fm N

N =

=

Where, E = 8.5V for secondary side

N =

=

= 52.18 turns = 52 turns approx.

A copper wire of gauge 26 was used in the winding because of the

recommended current rating of 1.3A which is closest to the desired secondary

current of 1A.

The primary side remains untouched as it was manufactured to work with 220V.

3.12 RECTIFICATION

The IN4007 diode converts the AC current to DC and satisfies charging

current demands of the filter capacitor. The arrangement of the diodes is called

a bridge rectifier. Rectification is done by the PN junction diodes. The DC

voltage varies above and below an average value. This variation is called ripple

voltage. In order to reduce ripple voltage to a very small value, the DC voltage

needs to be filtered.


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3.13 FILTER CAPACITOR

Filter capacitor was chosen to be large enough to reduce the ripple

voltage contained in a rectified voltage, to a relatively filtered voltage which

resembles a smooth DC voltage as much as possible.. To determine the proper

value of capacitor used, the equation given below is employed:

i = 3.4

Where q = CV 3.5

i =

C =

dV = Vr (Ripple voltage), and dt =

T =

Thus dt =

C =

=

i = 1A, f = 50Hz,

Vp = 12V and Vr = 10% of Vp

Vr =

12 = 1.2V

C =


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=

= 8.333 10-6

F

= 8,333 F

A capacitance value of 6,800 F was chosen due to availability, with a voltageof 25V which is above the supply voltage.

3.14 REGULATOR (LM7805)

The LM7805 regulator is a three terminal positive regulator which can

deliver an output current of up to 1A. It receives the input of a constant DC

voltage and supplies as output a somewhat lower value of DC voltage, which it

maintains fixed or regulated over a wide range of load current or input variation.

The LM7805 regulator maintains a +5V dc supply voltage to the system.

Fig. 3.3: LM7805 Regulator.


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3.2 INFRARED SENSOR UNIT

Two pairs of sensors are used for the entire system in an ideal situation;

each pair for the entrance and exit doors. The sensor unit arrangement is in such

a way that it consists of two pairs of infrared receiver to provide signals for the

microcontroller whenever there is an obstruction through the entrance or exit

door. For the design, two conditions are considered: first, when light rays are

focused on the infrared receiver, and secondly when the rays are being

interrupted.

When light rays of are focused on the infrared receiver, the output voltageis low and when the light rays are interrupted, the output voltage increases.

Each pair of sensors is separated by a reasonable distance such that the

passage of a person or other moving objects cannot obstruct the sensor pair

separation. The sensor is conveniently installed on both sides of the automatic

door frames. This consists of an infrared LED directed at an infrared receiver.

For the purpose of simplicity and elimination of obscurity, the researcher

chooses to use the infrared receiver and infrared LED. In this case, the infrared

receiver and LED are placed opposite each other on the door frame.

As the intensity of light falling on the infrared receiver increases, the

impedance of the infrared receiver decreases.

The two parts of the sensor unit- an infrared LED (light emitting diode)and an infrared receiver module, as discussed below.


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3.2.1 INFRARED LED

This is a high intensity diode that emits infrared light at a frequency of

38KHz as programmed by the timer 2 of the microcontroller which is not

visible to the naked eye. It operates on a 5V voltage source.

Fig. 3.4: Infrared LED circuit.

In order to determine the value of the series current-limiting resistor, the

following equation is used:

Rs =

.. 3.6

Where VF = the forward voltage for the LED

IF = the continuous forward current of the LED

From the infrared LED datasheet,

VF = 1.2V, thus for the two LEDs VF = 2 1.2 = 2.4V

IF = 20mA = 20 10-3A

Vcc = 5V


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Thus Rs =

Rs =

= 130

The value of 120 was chosen due to market availability.

3.2.2 INFRARED RECIEVER MODULE

When infrared light falls on the infrared receiver, a low signal is observed

at the output of the receiver. This low signal at the base doesnt bias the

transistor, thus the microcontroller then sees a high signal (Vcc) at its input pin.

When the infrared light is obstructed, a high signal is observed at the output of

the receiver, which biases the transistor to switch the ground. The

microcontroller under this condition sees a low signal (0V) at its input pin.

Fig. 3.5: Infrared Receiver circuit.


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The 100 resistor and 4.7uF capacitor connected to the infrared receiver arerecommended in the datasheet to suppress power supply disturbances.

Thus, the output of the sensor unit is either logical high or low. The

software developer is at liberty of considering either logic high or low as they

write the program.

The transistor is a three-layer semiconductor device consisting of either

two n- and one p-type layers of material or two p- and one n-type layers of

material. The former is called an NPN transistor; while the latter is called a PNP

transistor. Application of transistors is not limited solely to the amplification ofsignals. Through proper design it can be used as a switch for computer and

control applications.

For the base resistor of the transistor used in the receiver circuit ,

= 3.7

=

Where Vcc = 5V, and Rc = 10K (pull up resistor)

= 5 / 10K

= 0.5mA

=

= 0.5mA / 10

= 0.05mA = 50A

Also, ............................................................................... 3.8


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=

= 86K

The closest standard resistor value of 82K was chosen for the base resistor.

3.3 MOTOR CONTROL DRIVER AND ACTUATOR

The door control unit is made of the motor driver and a DC motor as explained

below;

3.3.1 L293D MOTOR DRIVER

The L293D is a quadruple drivers capable of delivering bidirectional

drive currents of up to 600mA at voltages from 4.5V to 36V.As the

microcontroller ports are not powerful enough to drive DC motor directly, a

L293D chip is used, it is a 16 pin chip. The pin configuration is as shown in

figure 3.5, to set appropriate level at two pins of the microcontroller to control

the motor. Since this chip controls two DC motor there are four input and output

pins for the four drivers in the IC. The driver 1 and driver 2 controls the first

motor clockwise and anticlockwise directions while driver 3 and driver 4

controls the second motor in the same way. There are also two enable pins they

must be high (+5V) for operation, if they are pulled low(GND), the motor will

stop.


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Fig 3.6: L293D Motor Driver.

3.3.2 DC MOTOR

A motor is an electromechanical device that converts electric energy intomechanical energy. Its action is based on the principle that when a current-

carrying conductor is placed in a magnetic field, it experiences a mechanical

force whose direction is given by Flemings Left-Hand Rule and whose

magnitude is given by; F=BIL Newton

Where, F=Mechanical force in Newton (N)

B=Magnetic field in Weber (Wb)

I=Current through the conductor in Amperes (A)

L=Length of Conductor in meters (m)


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3.4 DISPLAY UNIT

The display unit is a liquid crystal display (LCD). It is a thin flat panel

used for electronically displaying information. It is low electrical power

consumption enables it to be used in battery- powered electronics equipment. It

is an electronically-modulated optical device made up of any number of pixels

filled with liquid crystals. They use far less power than comparable LED

displays because they block or pass the light from other sources rather than emit

their own. The pin connection is as shown below;

Fig. 3.7: A Liquid Crystal display (LCD).

3.5 CPU MODULE

The AT89S52 is a low-power, high-performance CMOS 8-bit

microcontroller with 8K bytes of in-system programmable Flash memory. The

device is manufactured using Atmels high-density non-volatile memory


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technology and is compatible with the industry- standard 80C51 instruction set

and pin out. The on-chip Flash allows the program memory to be reprogrammed

in-system or by a conventional non-volatile memory programmer. By

combining a versatile 8-bit CPU with in-system programmable Flash on a

monolithic chip, the Atmel AT89S52 is a powerful microcontroller which

provides a highly-flexible and cost-effective solution to many embedded control

applications. The AT89S52 provides the following standard features: 8K bytes

of flash, 256 bytes of RAM, 32 I/O lines, two data pointers, three 16-bit

timer/counters, a six-vector two-level interrupt architecture, a full duplex serial

port, on-chip oscillator, and clock circuitry.

3.6 SOFTWARE DESIGN

SOFTWARE DEVELOPMENT PROCEDURE

Designing software for the automatic door opener was not a trivial task.

In the development cycle of a microcontroller base system, decisions are made

on the parts of the system to be realized in the hardware design and the parts to

be implemented in software. The software is decomposed into modules so that

each can be individually tested as a unit and debugged before the modules are

integrated and tested as a software system in order to ensure that the softwaredesign meets its specification.

The program for the system is written in assembly language for speed

optimization. Assembly code represents halfway position between machine

code and high level language. The assembly code is usually mnemonic derived

from the instruction itself, i.e. LDA is derived from LOAD the Accumulator.

Assembly code is thus simple to remember and use when writing programs.


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When entering an assembly program into a microcontroller, the assembly

code must first be converted into machine code. For short programs, of a few

lines, this relatively easy and usually requires that the programmer construct a

table which contains the assembly mnemonics and the equivalent machine code.

This technique is known as Hand Assembly and is limited to program of about

one hundred lines or less.

For longer programs, a separate program called an assembler program, is used

to convert the assembly code into machine code which is placed directly into

the microcontroller memory.

The software was designed using the following steps:

i. Algorithm

ii. Flowchart

iii. Assembly Language Codes

3.6.1 ALGORITHM

A step by step statement showing the chain of steps involved in solving a

problem. An ordered sequence of well defined and effective operations which

terminates in a finite amount of time. The algorithm is as shown;

- Start

- Generate 38KHz frequency

- Check sensor for interrupt

- Open door

- Check opposite sensor for interrupt

- Close door

- Display in (or out) count on LCD

- Stop.


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3.6.2 FLOWCHART

Flowchart can be defined as graphic representation of the definition,

analysis and solution of a problem, or a chart that pictorially displays the chain

of steps involved in solving a problem. The flowchart for the program is

illustrated in appendix 1.

3.6.3 ASSEMBLY LANGUAGE

An assembly language is a low-level language for programming

computers. It implements a symbolic representation of the numeric machine

codes and other constants needed to program a particular CPU architecture. This

representation is usually defined by the hardware manufacturer, and is based on

abbreviations (called mnemonics) that help the programmer remember

individual instructions, registers, etc. An assembly language is thus specific to a

certain physical or virtual computer architecture (as opposed to most high-level

languages, which are portable). The program is as shown in appendix 2.

3.7 COMPONENT ASSEMBLING

Assembling is a very important stage in the construction process. It is

usually the transfer of an idea from abstract to the concrete world. It involves

inserting, connecting or joining the various components in a vero-board in

accordance with the schematic diagram. The Vero-board consists of two faces, a

free face and a face with copper coatings in form of parallels lines. It also

contains many perforated holes that facilitate the insertion of component.

In this project, the components were inserted through the free face and

interconnected in the copper face using soldering iron and lead. The cutting of


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the line was done by razor blade, and the joining of two parallel lines was done

with jumper wires. IC sockets were used to accommodate the IC, a way of

avoiding damaging of the ICs by excessive heat dissipated by the soldering

iron.

3.8 OUTER CASING DESIGN

The outer casing is made of wood. This choice was given priority for its

structural rigidity. The casing houses the entire circuitry, dc motor and door

assembly, power supply unit, moving mechanism and its ancillary items. On the

front (entrance) of the casing is the arrangement of the sensor unit, consisting of

the infrared (LED), a source of light beam carefully aligned and focused on the

infrared receiver module. On the rear side of the casing is a hole through which

the power supply cable passes. A snapshot of the casing is shown in the

appendix.

Fig. 3.8: Outer casing design

23cm

48cm

9cm


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CHAPTER FOUR: PERFORMANCE AND COST

EVALUATION

4.0 INTRODUCTION

This chapter reveals the tests carried out on the project work and the

performance /results obtained. It also provides a list of the components used and

the cost.

4.1 TESTING/PERFORMANCE

Prior to the final assembling of the automatic door opener each unit was

subjected to various characteristics test. Use was made of a digital multi-meter

to determine and compare the voltage level at some strategic points. For

instance;

-In the power supply unit, the dc motor requires 5V while the electroniccircuitry was powered by 5V. It was expedient that the voltage output be tested

before coupling.

-Voltages on the microcontroller input and output pins were also tested.

Pins 40 and 31 should be at Vcc Potential, Pin 20 at ground potential.

-The motor was also observed to rotate in a clockwise and anticlockwise

direction when there was an interruption in the respective sensor pair.

- The LCD displayed the count of the number of persons that the

microcontroller registered and increments, as persons enter or leave through the

door.


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Parameter Measured Value

Frequency at P1.0 of the

microcontroller and at the infraredLED

37.97KHz

Voltage at the infrared receiver

module with no obstruction in the line

of sight transmission

0V

Voltage at the infrared receiver

module with obstruction in the line of

sight transmission

1.76V

Table 4.1: Test results.

4.2 LIST OF COMPONENTS AND COSTING

The various components selected for the assembling of the automatic door

opener with counter and LCD display and their costs are displayed in the table

below;

S/NO. COMPONENT QUANTITY RATE (N) AMOUNT(N)

1. Resistor (120) 1 5 5

2. Resistor (100) 2 5 10


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3. Resistor (82K) 3 10 30

4. Resistor (10K) 7 10 70

5. Variable resistor

(10K)

1 30 30

6. Capacitor

(25V,6800uF)

1 100 100

7. Capacitor

(16V,4.7uF)

2 20 40

8. Capacitor

(16V,10uF)

1 30 30

9. Capacitor (30pF) 2 30 60

10. Diode (IN4007) 4 5 20

11. Regulator (LM7805) 1 50 50

12. Power switch 1 40 40

13. Transistors (BC337

NPN)

3 30 90

14 Transistor (BC 327) 2 30 60

15. Infrared LED 2 150 300

16. Infrared receiver

module

2 350 700

17. Reset switch 1 20 20


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18. Quartz crystal 1 50 50

19. Transformer (8.5V) 1 1000 1000

20. DC motor (5V) 1 1000 1000

21. Vero board 2 100 200

22. Microcontroller

AT89S52

1 400 400

23. Motor driver

(L293D)

1 250 250

24. Casing 4000 4000

Total 9,325

Table 4.2: Component costing


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CHAPTER FIVE: CONCLUSIONS

5.0 SUMMARY

This project work attempts to proffer a lasting solution to the long

lingered difficulties and inconveniences with door opening in an unprecedented

manner. Unprecedented in the sense that it employs the microcontroller as the

brain of the system, thereby eliminating the use of unnecessarily large number

components.

The use of assembly language to program the microcontroller guarantees

excellent performance and accuracy beyond average. Information surfed from

the internet and relevant books form the sources of data used to achieve the

desired goal.

Components selected were assembled on a Vero-board in accordance

with schematic diagram. The assembly was tested with relevant instrument

before the final packaging and casing. Tested results reveal that:

The voltage measured at some strategic points were approximately

tending to the value obtained from calculations.

This can be justified with fact that,

i. No conducting material is perfect.

ii. Same components of some values do not measure perfectly the samewhen tested with multimeter.

iii. Joints made with soldering lead introduce capacitive effects especially

if not properly soldered.

Instead of a 5V dc motor of used in this model, if a motor of higher torque were

acquired, it could be mounted in any real standard door for automatic operation.


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5.1 CONCLUSION

The findings aforementioned indicate that the project was successful.

This proves beyond reasonable doubt that the system is more reliable because of

the ease with which instructions could be written to the chip in assembly

language, coupled with this is the ease with which the program could be

modified. Despite the prevalent advantages accompanying this system, it should

not be accepted as a perfect and flawless product.

5.2 RECOMMENDATIONS

The researcher recommends the use of this project in domestic buildings,

schools, hospitals, industries etc.

For further study, modification and improvement, the researcher

recommends:

The program could be modified by writing a program for displaying a

count of up to five hundred persons or more so as to obtain the count of persons

entering or leaving large public buildings.

The University should provide a modality for ensuring that components

necessary for any design are readily available and found in the laboratories.

Separate entrances could be used in the design- one for entrance and exit

respectively, and the program modified accordingly.

The program could also be modified to include a display of the remaining

persons in the building which would be an arithmetic difference of the in and

out count.


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REFERENCES

1. Shoewu O. and Baruwa O.T. (2004).Design and construction of

microprocessor Based Automatic Gate. Unpublished B.sc project, Lagos

State University: Epe, Nigeria

2. Krutz, R.L.(1980).Microcontroller and Logic Design, John Wiley and

Sons, Inc: New York, NY

3. McGlen, L. (1978).8080A, 8085 Assembly Language Programming.

McGraw-Hill, inc: New York, NY

4. Private Door Information. Lombard, IL; www.privatedoor.com

5. Floyd L.T. (2002). Electronic Devices, Sixth Edition, Pearson Education

Singapore pte. Limited India.

6. Neal S.W.(1998).Digital System; Principles and Application. Eigth

Edition Prentice-Hall International: Princeton, NJ.

7. Tokheim, R.L. (1988).Digital Electronics; Principles and Application.

Fifth Edition. McGraw-Hall, Inc: New York, NY.

8. Mazidi, A.M. and Mazidi J.(2000).The 8051 microcontroller and

Embedded System.

9. Theraja B.L and A.K Theraja, (2005).A Textbook of Electrical

Technology S.Chand Company Limited. Ram Nagar, New Delhi-110005.

10.Robert L.B. and Louis N.(2004).Electronic Devices and Circuit Theory.

Eight Edition, Prentice-Hall of India Private Limited, New-Delhi


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APPENDIX

Plate 1: The Assembled Components.

Plate 2: The Outer Casing.


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Fig. A: Complete circuit diagram.

galant project

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