The document describes a project to design and implement a system to display the number of free seats available and monitor the room temperature in a library. The system uses passive infrared sensors (PIR) to detect students entering and leaving the library. An Arduino microcontroller is used to count the number of students and control a fan and LCD display based on temperature readings from a temperature sensor. When implemented, the system will automatically count students and display the number of free seats remaining on an LCD. It will also monitor and control the room temperature by adjusting the fan speed based on a temperature threshold.

1. ASSOSA UNIVERSTIY
COLLAGE OF ENGINEERING
DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING
STREAM CONTROL
TITLE ON: DESIGN AND IMPLEMENTATION OF DISPLAYING FREE
SEATS AVAILABLE AND MONITOR THE ROOM TEMPERATURE IN
THE LIBRARY.
GROUB NAME ID NO
1) ASMARE HABTU………. ………………………………...ETR/ 0337/08
2) AYELE KANTURE………………………………………. .ETR/0346/08
3) BEZUALEM ASFA………………………………………... ETR/0378/08
4) MISGANAW FENTAHUN …………………………………ETR/0746/08
5) MULUALEM ABEBE ……………………………………..ETR/0773/08
Advisor Name Mr. Talegeta M. (Msc)
Submission Date: Febrawary
Assosa
Ethiopia

2. Declaration

3. Acknowledgment

4. Abstract
In this project we develop and build an automatic monitoring and displaying free seats available
in the library. This project consists of simple circuit which consists of Passive Infrared Sensor
(PIR) pair, temperature sensor and LCD and fan at output section. With the help of this system it
is possible to count the number of students and monitor the temperature at Schools, Banks, shops
and etc. But this project is used for library for counting students and monitoring the temperature.
PIR pair and temperature sensor is the input section of this circuit. As soon as the student enters
the door a high to low pulse goes to receiver of PIR pair and the temperature sensor senses the
temperature inside the library. If the temperature is beyond the threshold value then, the fan goes
to high. In this project we use Arduino microcontroller for counting, monitoring the fan and
provides output to the input of LCD for displaying and finally it displays free seats available for
students on LCD.

5. Table of Contents

6. List of Figures

7. List of Acronym

8. CHAPTER ONE
INTRODUCTION
1.1 Background
Automatic monitoring and displaying free seats available in library is designed to count the number
of students entering or leaving the library. When student enters the library, the count would be
increased. Whereas on leaving, the count would be decreased. PIR sensors are used for motion
detection and the whole counting operation is done by the Arduino microcontroller. PIR sensors
allow you to sense motion, almost always used to detect whether a human has moved in or out of
the sensors range. They are small, inexpensive, low-power, easy to use and don't wear out. For that
reason they are commonly found in appliances and gadgets used in homes or businesses. They are
often referred to as PIR, "Passive Infrared ray “or "IR motion" sensors. It can detect humans,
animals and other objects. The output from each sensor is fed to the Arduino microcontroller. The
output from sensor would be a logic high signal if motion is detected by Arduino microcontroller
and accordingly the count would be increased or decreased. The Arduino Uno is a microcontroller
board based on the ATmega328. It has 14 digital input/output pins (of which 6 can be used as
PWM outputs), 6 analog inputs, a 16 MHz clock, a USB construction, a power jack, & a reset
button. The LM35 is the temperature sensor, whose output voltage proportional to temperature and
it sense the temperature of the library. In today’s world, there is a continuous need for automatic
appliances. With the increase in standard of living, there is a sense of urgency for developing
circuits that would ease the complexity of life. Also if at all one wants to know the number of
people present in library so as not to have congestion, this system proves to be helpful. The main
purpose of our system is to save energy and the efforts required to switch on the lights. Instead of
switching on/off the lights in the library the lights adjust the intensity automatically. To make a
controller based model to count number of persons visiting the library and accordingly light up the
library .To know the number of people present in library so as not to have congestion. when the
number of student entering to the library as more to exsoust more amount carbon dioxide in the
human being due to this temperature increase in the library and also fan available in the room.

9. 1.2 Objectives
General Objective.
Design and implementation of displaying free seats available and monitor the room temperature in the
library.
Specific Objective
 To know how infrared sensors detect person entering and leaving a library.
 To know how to interface infrared sensors with Arduino microcontroller.
 To design counting system.
 To know how to interface liquid crystal display with Arduino microcontroller.
1.3 Statement of The problem
Many of libraries in our country have limited number of seats used for students. Students go to
library unconscious of how many seats available free. Some students go to library early while
others join study being late. Early students get free seats while those who are late search for a seat
for a long period of time and may or may not get the seat. This is tiresome and time consuming
which makes students‟ schedule disordered and lose their time management system. Therefore
there must be the counting system to count students entering and leaving the gate and display
number of seats available free on the gate of library. In addition to this when the temperature is
increases beyond the normal level when the number of students entering is large; it is no
comfortable for study. Therefore, there must be requiring automatic monitoring for the
temperature. To solve the above stated problem there may exist manual counting, which is
difficult, tiresome and in accurate. To avoid these we designed a system that count students
entering and leaving, and display the total number of seats left free in library. The system uses
passive infrared sensors to detect each students entering and leaving to the library. Arduino
microcontroller to display number of seats free on LCD display unit by subtracting total number
of students leaved from those entering.

10. 1.4 Significance of a project
The design and simulation of automatic light controller for library with visitor counter is used to
Develop a smart system which provide energy efficient and automatically controlled room lighting
in library, in addition to it help us to count the number of person present in the library. This project
up on completion and successful implementation play a crucial role in: In library where the
capacity of room is limited and should not be exceeded by displaying the actual number of persons
inside the room. Infrared sensor technology accurately counts students moving in and out of a
library or general area.
 Comfortable condition for study
 Small and light weight design allows installation on virtually any surface
 Display counters equipped with screens showing count values
 Valuable tool to manage student’s time
1.5 Scope of The project
This project is designed and developed for those areas like library, banks and shops with the
following most interesting features: This project has the following goals
 To provide reliable and high quality light controlling system for libraries.
 It will minimize the time and energy loss of human to turn on and off the light.
1.6 Limitation of project
It is used only when one single person cuts the rays of the sensor hence it cannot be used when two
person cross simultaneously. And also it does not display or locate the exact position of the seat.
Arduino Uno is the heart of the circuit. If controller is damaged the whole system will be interrupt

11. CHAPTER TWO
2. LITRATURE REVIEW
Before the advancement of information systems, counting of person passing through a location
used to been done manually. The room appliances are still mostly controlled manually in most
parts of the world that often leads to power wastage in case of personal negligence. With the
innovation in technology, many electronic systems such as bidirectional visitors‟ counters and
automatic appliance controllers have been developed to keep check of the visitors visiting a hall
and controlling the lights of that room. The heart of these counters is a microcontroller that counts
the seats up and down using output from an IR sensor. These sensors consist of an IR
transmitter/receiver (TX/RX) pair. The design can be quite simple for two door systems. Where
one door is dedicated for entering and the other for leaving. One sensor monitors for the person
entering and the other one monitors the person leaving the room. But the design becomes more
challenging for single door systems where all the persons are entering and leaving through the
single channel. The conventional systems employ IR transmitter receiver pair, each installed on
opposing sides of the door. In comparison to the older systems, we have used practically applicable
PIR sensors rather than ordinary IR sensors. Typical IR sensors used by earlier developers, have
much limited range. They can be used to successfully develop a model of sensing range of a few
centimeters to inches. However, for practical application on several feet wide doors, PIR sensors
are the best choice that we have used in our design. However, the idea was generated based on a
similar technique used for bidirectional Visitor Counter with automatic room light controller by
using Arduino Uno. Two-way visitor counter based on microcontrollers and designed and
presented to count visitors to an auditorium, room, offices, shopping centers, sports venues, etc.
The system counts both the incoming and outgoing visitor of the auditorium or room or other place
where it is placed. A counter that can change its state in any direction, under the control of an
ascending selector input, is known as an up counter. It can be used to count the number of people
entering a room in the upstairs mode at the front door. In the descent mode, you can count the
number of people leaving the room reducing the count at the exit door. It can also be used on the
doors of parking areas and other public places. This circuit is divided into three parts: sensor,
controller and counter.

12. The sensor would observe an interruption and provide an input to the controller that would operate
the counter in up / down mode depending on the setting of the selector. The circuit operates
according to the principle of IR detection. Two sets of IR sensors consisting of an IR LED and a
phototransistor are placed at two ends. The output of each sensor is fed to the microcontroller. In
normal operation, the infrared LED light would fall on the phototransistor and this would act. The
sensor output would be a low logic signal in this case. In case of any interruption (due to any
person crossing the road), the phototransistor would stop driving or drive less and the sensor output
would be a high logic signal. The low-to-high transition for each pair of sensors is detected by the
microcontroller and, as a result, the count will increase or decrease. From the above review we
are trying to design and implement to display the number of free seats and automatic monitoring
of the library by using PIR sensor.

13. CHAPTER THREE
METHODOLOGY AND MATERIAL REQUIRED
3.1 Methodology
This project started with getting idea and concept of displaying free seats available and monitor
the room temperature and reading some literature reviews. The methodology of the project
includes a different number works that are done to achieve the goal of the system. In our work we
can consider different electronic and electromechanical materials that can perform our tasks. There
is list of material used. Arduino controller, PIR sensor, DC driver, liquid crystal display and power
supply. There also need software device to program Arduino controller.the procedure of
methodology listed below.
Figure Sequence of methodology

14. 3.2 Block diagram of the proposed System
We use an passive infrand sensor circuit along with LCD display. Our system first uses the PIR
sensor in order to detect the human movement. The sensor provides analog output. This analog
output is now provided to the microcontroller for further processing. Based on the input the
microcontroller observing and image identification, and displays the same on an LCD display. A
temperature sensor has been used to measure the temperature of the room and the speed of the fan
is varied according to the room temperature using PWM technique. The duty cycle is varied from
0 to 30 to control the fan speed depending upon the room temperature and also displaying in the
LCD
Figure Block diagram of the proposed System
3.3 Hardware and Software Description
3.3.1 Hardware Description
Arduino Microcontroller:- is an open-source platform used for building electronics projects.
Arduino consists of both a physical programmable circuit board (often referred to as a
microcontroller) and a piece of software, or IDE (Integrated Development Environment) that runs
on your computer, used to write and upload computer code to the physical board AND ALSO
Arduino board is the central unit of the system. The Arduino Uno is the microcontroller board
based on the AT mega 328. It is a programmable microcontroller for prototyping
electromechanical devices.it has 14 digital inputs/output pins (of which 6 can be used as PWM
output),6 analog input. Each of the 14 digital pins on the Uno can be used as an input or output,
Arduino UNO
Temperature
sensor
Fan
PIR Sensor
LCD
Power
Supplay

15. using pin Mode(),digital Write(), and digital Read() functions. They operate at 5 volts. Each pin
can provide or receive 20 mA as recommended operating condition and has an internal pull-up
resistor (disconnected by default) of 20-50k ohm. A maximum of 40mA is the value that must not
be exceeded on any I/O pin to avoid permanent damage to the microcontroller. This Arduino board
was able to perform all the functions needed. It was exactly how the description said and matched
all of the necessary requirements. The Arduino does not need a separate piece of hardware (called
a programmer) in order to load new code onto the board – you can simply use a USB cable.
Key features of Arduino: Arduino boards are able to read analog or digital input signals from
different sensors and turn it into an output such as activating a motor, turning LED on/off, and
many other actions. We can control your board functions by sending a set of instructions to the
microcontroller on the board via Arduino IDE (referred to as uploading software).Additionally;
the Arduino IDE uses a simplified version of C++, making it easier to Learn to program. The
Arduino has several different kinds of pins, each of which is labeled on the board and used for
different functions.
Components of Arduino
 Power (USB / Barrel Jack)
The Arduino UNO can be powered from a USB cable coming from your computer or a wall
power supply in a barrel jack.
 GND: Short for „Ground‟. There are several GND pins on the Arduino, any of which can
be used to ground your circuit.
 5V & 3.3V: the 5V pin supplies 5 volts of power and the 3.3V pin supplies 3.3 volts of
power.
 Analog: The area of pins under the „Analog In‟ label (A0 through A5 on the UNO) is
Analog input pins. These pins can read the signal from an analog sensor (like a temperature
sensor) and convert it into a digital value that we can read.
 Digital: Across from the analog pins are the digital pins (0 through 13 on the UNO). These
pins can be used for both digital input (like telling if a button is pushed) and digital output
(like powering an LED).
 PWM: You may have noticed the tilde (~) next to some of the digital pins (3, 5, 6, 9, 10,
and 11 on the UNO). These pins act as normal digital pins, but can also be used for
something called Pulse Width Modulation (PWM).

16.  AREF: Stands for Analog Reference. Most of the time you can leave this pin alone. It is
sometimes used to set an external reference voltage (between 0 and 5 Volts) as the upper
limit for the analog input pins.
 Reset Button: The Arduino has a reset button. Pushing it will temporarily connect the reset
pin to ground and restart any code that is loaded on the Arduino.
 TX RX LEDs: These LEDs give indication whenever our Arduino is receiving or
transmitting data.
Figure Arduino Uno
Arduino program
 Digital Read (pin): Reads the digital value at the given pin.
 Digital Write (pin, value): Writes the digital value to the given pin.
 Pin Mode (pin, mode): Sets the pin to input or output mode.
 Analog Read (pin): Reads and returns the value.
 Analog Write (pin, value): Writes the value to that pin.

17.  Serial. Begin (baud rate): Sets the beginning of serial communication by setting the bit rate.
PIR Sensor :-The electronic sensor used to detect the movement of human being within a certain
range of the sensor is called as PIR sensor or passive infrared sensor. A PIR sensor detects the infrared
light radiated by a warm object. It consists of pyro electric sensors which introduce changes in their
temperature (due to incident infrared radiation) into electric signal. When infrared light strikes a
crystal, it generates an electrical charge.
Operating Principle of PIR sensor
The modern studies in the field of quantum physics tells us the fact each and every object when it
is placed at a temperature above absolute zero, emits some energy in the form of heat and this heat
energy is in fact the form of infrared radiations. Passive elements are those elements that don’t
generate their own voltages or energy. They just only measures things. So we can say that this
sensor is a passive infrared sensor and it doesn’t generate anything by itself. It is only capable to
measure the radiations emitted by other objects around it. It measures those radiations and does
some desired calculations on them.
Applications of PIR sensor
Some of their features and practical applications are listed below as:
 They are able to sense the detection of people and other objects.
 PIR sensors are also used in automatic lightening systems. In these types of systems, when
a person comes in the vicinity of the sensor then, the lights are automatically turned ON.
 They are used in outdoor lightening systems and also in some lift lobbies. You may have
observed that when a person comes in front of the lift and if the doors are being closed
then, the doors are opened again. This is all due to PIR sensors.
 They are widely used in underground car parking system. At every parking position a PIR
sensor is installed and when that position is vacant then, a green light glows over that place
which means you can park here. And if that position has been occupied then, a red light
will glow, representing that this position is already occupied.
 PIR sensor is much compatible sensor and it has the ability to detect a particular motion
and the output of this system is very sensitive and doesn’t have any kind of noise in it.

18. Figure PIR Sensor
The PIR sensor has three pins.
 Ground pin.
 Vout power supply pin.
 Output pin which is connected to Arduino pin.
Temperature Sensor:- is measure the amount of heat energy or even coldness that is generated
by an object or system, allowing us to “sense” or detect any physical change to that temperature
producing either an analogue or digital output. Temperature sensors are used in several
applications namely AC system environmental controls, medical devices, food processing units,
chemical handling, controlling systems, automotive under the hood monitoring and etc. The
different kinds of sensors are categorized by the sensing capacity of the sensor as well as the range
of applications. The different types of temperature sensors include the following.
 Thermocouple
 Thermistors
 Resistor temperature detectors
 The LM35 Temperature Sensor
LM35 Temperature Sensor
The LM35 is one kind of commonly used temperature sensor that can be used to measure
temperature more correctly. The LM35 has an output voltage that is proportional to the Celsius
temperature. The scale factor is 0.01V/°C.The LM35 does not need any external calibration and
maintains an exactness of +/- 0.4°C at room temperature. One more significant characteristic of
this sensor is the LM35 temperature sensor is used to detect precise centigrade temperature. The
output voltage of this IC sensor is linearly comparative to the Celsius temperature. The operating
voltage range of this LM35 ranges from-55˚ to +150˚C and it has low-self heating. This is operated
under 4 to 30 volts..
The applications of LM35 temperature sensor include the following

19.  Measuring temperature of a particular environment
 Providing thermal shut down for a component/ circuit
 Checking Battery Temperature
Figure LM35 temperature sensors
LM35 temperature sensor has three pins:
 Vs connected to +5v source.
 Vout connected to Analog inputs of Arduino.
 GND connected to GND.
L293D is a typical Motor driver or Motor Driver IC which allows DC motor to drive on either
direction. L293D is a 16-pin IC which can control a set of two DC motors simultaneously in any
direction. It means that you can control two DC motor with a single L293D IC. Dual H-bridge
Motor Driver integrated circuit (IC). It works on the concept of H-bridge. H-bridge is a circuit
which allows the voltage to be flown in either direction. As you know voltage need to change its
direction for being able to rotate the motor in clockwise or anticlockwise direction, Hence H-bridge
IC are ideal for driving a DC motor. In a single L293D chip there are two h-Bridge circuit inside
the IC which can rotate two dc motor independently. Due its size it is very much used in robotic
application for controlling DC motors. Given below is the pin diagram of a L293D motor
controller. There are two Enable pins on l293d. Pin 1 and pin 9, for being able to drive the motor,
the pin 1 and 9 need to be high. For driving the motor with left H-bridge you need to enable pin 1
to high. And for right H-Bridge you need to make the pin 9 to high. If anyone of the either pin1 or
pin9 goes low, then the motor in the corresponding section will suspend working. It’s like a switch.
The L293D is a 16 pin IC, with eight pins, on each side, dedicated to the controlling of a motor.

20. There are 2 INPUT pins, 2 OUTPUT pins and 1 ENABLE pin for each motor. L293D consist of
two H-bridge. H-bridge is the simplest circuit for controlling a low current rated motor
Figure L293D IC
Pin description
 1 - Enable 1-2, when this is HIGH the left part of the IC will work and when it is low the
left part won’t work.
 2 - INPUT 1, when this pin is HIGH the current will flow though output 1
 3 - OUTPUT 1, this pin should be connected to one of the terminal of motor
 4, 5 - GND, ground pins
 6 - OUTPUT 2, this pin should be connected to one of the terminal of motor
 7 - INPUT 2, when this pin is HIGH the current will flow though output 2
 8 - VCC2, this is the voltage which will be supplied to the motor.
 16 - VCC1, this is the power source to the IC. So, this pin should be supplied with 5 V
 15 - INPUT 4, when this pin is HIGH the current will flow though output 4
 14 - OUTPUT 4, this pin should be connected to one of the terminal of motor
 13, 12 - GND, ground pins
 11 - OUTPUT3, this pin should be connected to one of the terminal of motor

21.  10 - INPUT 3, when this pin is HIGH the current will flow though output 3
 9 - Enable 3-4, when this is HIGH the right part of the IC will work and when it is low
the right
 part won’t work.
Liquid crystal display A 16x2 LCD display is very basic module and is very commonly used in
various devices and circuits. These modules are preferred over seven segments and other multi
segment LEDs. The reasons being: LCDs are economical, easily programmable, have no limitation
of displaying special & even custom characters (unlike in seven segments), animations and so on.
A 16x2 LCD means it can display 16 characters per line and there are 2 such lines. This LCD has
two registers, namely, Command and Data. The command register stores the command instructions
given to the LCD. A command is an instruction given to LCD to do a predefined task like
initializing it, clearing its screen, setting the cursor position, controlling display etc. The data
register stores the data to be displayed on the LCD
Figure Liquid crystal display
3.3.2 Software Description
Proteus:- is a simulation and design software tool. It also possess 2D CAD drawing feature. It is
a software suite containing schematic, simulation as well as PCB designing. ISIS is the software
used to draw schematics and simulate the circuits in real time. The simulation allows human access
during run time, thus providing real time simulation. ARES is used for PCB designing. It has the
feature of viewing output in 3D view of the designed PCB along with components. The designer
can also develop 2D drawings for the product.
Arduino:- is an open source microcontroller which can be easily programmed, erased and
reprogrammed at any instant of time. Based on simple microcontroller boards, it is an open
source computing platform that is used for constructing and programming electronic devices. It

22. is also capable of acting as a mini computer just like other microcontrollers by taking inputs and
controlling the outputs for a variety of electronics devices. Arduino uses a hardware known as the
Arduino development board and software for developing the code known as the Arduino IDE
(Integrated Development Environment).
3.3.3 Flow chart of the system
Flow chart is ideal for a process that has sequential process steps. The step will be executed in a
simple order that may change as a result of some simple decisions
Figure Flow chart of the system

23. CHAPPTER FOUR
System Design and Analysis