CHAPTER :- 1Project Overview

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1. Introduction Of Project

1.1 Project Definition:

Project title is “AUTOMATIC ROOM LIGHT CONTROLLER WITH

BIDIRECTIONAL VISITOR COUNTER “.

The objective of this project is to make a controller based model to count number of

persons visiting particular room and accordingly light up the room. Here we can use sensor

and can know present number of persons.

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 room so as not to

have congestion. This circuit proves to be helpful.

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1.2 Project Overview

This Project “Automatic Room Light Controller with Visitor Counter using

Microcontroller is a reliable circuit that takes over the task of controlling the room lights as well

us counting number of persons/ visitors in the room very accurately. When somebody enters into

the room then the counter is incremented by one and the light in the room will be switched ON

and when any one leaves the room then the counter is decremented by one. The light will be only

switched OFF until all the persons in the room go out. The total number of persons inside the

room is also displayed on the seven segment displays.

The microcontroller does the above job. It receives the signals from the sensors, and this

signal is operated under the control of software which is stored in ROM. Microcontroller

AT89S52 continuously monitor the Infrared Receivers, When any object pass through the IR

Receiver's then the IR Rays falling on the receiver are obstructed , this obstruction is sensed by

the Microcontroller

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CHAPTER :- 2BLOCK DIAGRAM AND ITS DESCRIPTION

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2.1 Basic Block Diagram

Enter Exit

Fig. 2.1 Basic Block Diagram

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Enter Sensor

Exit Sensor

Power Supply

Signal Conditioning

AT89S52

Light

Relay DriverSignal Conditioning

2.2 Block Diagram Description

The basic block diagram of the bidirectional visitor counter with automatic

light controller is shown in the above figure. Mainly this block diagram consist of

the following essential blocks.

1. Power Supply

2. Entry and Exit sensor circuit

3. AT 89S52 micro-controller

4. Relay driver circuit

1. Power Supply:-

Here we used +12V and +5V dc power supply. The main function of this

block is to provide the required amount of voltage to essential circuits. +12

voltage is given. +12V is given to relay driver. To get the +5V dc power supply

we have used here IC 7805, which provides the +5V dc regulated power supply.

2. Enter and Exit Circuits:-

This is one of the main part of our project. The main intention of this

block is to sense the person. For sensing the person and light we are using the

light dependent register (LDR). By using this sensor and its related circuit

diagram we can count the persons.

3. 89S52 Microcontroller:-

It is a low-power, high performance CMOS 8-bit microcontroller with

8KB of Flash Programmable and Erasable Read Only Memory (PEROM). The

device is manufactured using Atmel’s high-density nonvolatile memory

technology and is compatible with the MCS-51TM instruction set and pin out. The

on-chip Flash allows the program memory to be reprogrammed in-system or by a

conventional nonvolatile memory programmer. By combining a versatile 8-bit

CPU with Flash on a monolithic hip, the Atmel AT89S52 is a powerful

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Microcontroller, which provides a highly flexible and cost effective

solution so many embedded control applications.

4. Relay Driver Circuit:-

This block has the potential to drive the various controlled devices. In this

block mainly we are using the transistor and the relays. One relay driver circuit

we are using to control the light. Output signal from AT89S52 is given to the base

of the transistor, which we are further energizing the particular relay. Because of

this appropriate device is selected and it do its allotted function.

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CHAPTER :- 3SCHEMATIC DIAGRAM

Transmission Circuit:-

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Fig. 3.1 Transmitter circuit

Receiver Circuit:-

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Fig. 3.2 Receiver circuit

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CIRCUIT DESCRIPTION:

There are two main parts of the circuits.

1. Transmission Circuits (Infrared LEDs)

2. Receiver Circuit (Sensors)

1. Transmission Circuit:

Fig. 3.3 Transmitter circuit

This circuit diagram shows how a 555 timer IC is configured to function

as a basic monostable multivibrator. A monostable multivibrator is a timing

circuit that changes state once triggered, but returns to its original state after a

certain time delay. It got its name from the fact that only one of its output states

is stable. It is also known as a 'one-shot'.

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In this circuit, a negative pulse applied at pin 2 triggers an internal flip-

flop that turns off pin 7's discharge transistor, allowing C1 to charge up through

R1. At the same time, the flip-flop brings the output (pin 3) level to 'high'.

When capacitor C1 as charged up to about 2/3 Vcc, the flip-flop is triggered once

again, this time making the pin 3 output 'low' and turning on pin 7's discharge

transistor, which discharges C1 to ground. This circuit, in effect, produces a pulse

at pin 3 whose width t is just the product of R1 and C1, i.e., t=R1C1.

IR Transmission circuit is used to generate the modulated 36 kHz IR

signal. The IC555 in the transmitter side is to generate 36 kHz square wave.

Adjust the preset in the transmitter to get a 38 kHz signal at the o/p. around 1.4K

we get a 38 kHz signal. Then you point it over the sensor and its o/p will go low

when it senses the IR signal of 38 kHz.

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2. Receiver Circuit:

Fig. 3.4 Receiver circuit

The IR transmitter will emit modulated 38 kHz IR signal and at the

receiver we use TSOP1738 (Infrared Sensor). The output goes high when the

there is an interruption and it return back to low after the time period determined

by the capacitor and resistor in the circuit. I.e. around 1 second. CL100 is to

trigger the IC555 which is configured as monostable multivibrator. Input is given

to the Port 1 of the microcontroller. Port 0 is used for the 7-Segment display

purpose. Port 2 is used for the Relay Turn On and Turn off Purpose.LTS 542

(Common Anode) is used for 7-Segment display. And that time Relay will get

Voltage and triggered so light will get voltage and it will turn on. And when

counter will be 00 that time Relay will be turned off. Reset button will reset the

microcontroller.

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CHAPTER :- 4HARDWARE DESIGN & DESCRIPTIONS

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Hardware Design:-

Fig. 4.1 Snap of the entire circuit

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MicrocontrollerAT89S52

Infrared SensorTSOP1738

7-SegmentDisplay

Relay

Timer IC555

4.1 Procedure Followed While Designing:

In the beginning I designed the circuit in DIPTRACE software. Dip trace is a circuit

designing software. After completion of the designing circuit I prepared the layout.

Then I programmed the microcontroller using KEIL software using hex file.

Then soldering process was done. After completion of the soldering process I tested the

circuit.

Still the desired output was not obtained and so troubleshooting was done. In the process of troubleshooting I found the circuit aptly soldered and connected and hence came to conclusion that there was error in programming section which was later rectified and the desired results were obtained.

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4.2 List of Components:

Following is the list of components that are necessary to build the assembly of the Digital

Speedometer Cum Odometer:

Microcontroller – AT89S52

IC – 7805

Sensor – TSOP 1738 (Infrared Sensor)

Transformer – 12-0-12, 500 mA

Preset – 4.7K

Disc capacitor – 104,33pF

Reset button switch

Rectifier diode – IN4148

Transistor – BC 547, CL 100

7-Segment Display

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4.3 Description of Components

4.3.1 Microcontroller AT89S52:

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 Atmel’s high-density nonvolatile memory 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 nonvolatile

memory pro- grammar. 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, Watchdog timer, 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. In addition, the AT89S52 is designed with static logic

for operation down to zero frequency and supports two software selectable power saving

modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial

port, and interrupt system to continue functioning. The Power-down mode saves the

RAM con- tents but freezes the oscillator, disabling all other chip functions until the next

interrupt or hardware reset.

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FEATURES:-

8 KB Reprogrammable flash.

32 Programmable I/O lines.

16 bit Timer/Counter—3.

8 Interrupt sources.

Power range: 4V – 5.5V

Endurance : 1000 Writes / Erase cycles

Fully static operation: 0 Hz to 33 MHz

Three level program memory lock

Power off flag

Full duplex UART serial channel

Low power idle and power down modes

Interrupt recovery from power down modes

256 KB internal RAM

Dual data pointer

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4.3.2 TSOP1738 (INFRARED SENSOR)

Fig. 4.2 Infrared Sensor

Description:

The TSOP17.. – Series are miniaturized receivers for infrared remote control

systems. PIN diode and preamplifier are assembled on lead frame, the epoxy package is

designed as IR filter. The demodulated output signal can directly be decoded by a

microprocessor. TSOP17.. is the standard IR remote control receiver series, supporting

all major transmission codes.

Features:

Photo detector and preamplifier in one package

Internal filter for PCM frequency

Improved shielding against electrical field disturbance

TTL and CMOS compatibility

Output active low

Low power consumption

High immunity against ambient light

Continuous data transmission possible (up to 2400 bps)

Suitable burst length .10 cycles/burst

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Block Diagram:

Fig. 4.3 Block Diagram of TSOP 1738

Application Circuit:

Fig. 4.4 Application circuit

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4.3.3 555 ( TIMER IC):

Fig. 4.5 Timer IC(555)

Description:

The LM555 is a highly stable device for generating accurate time delays or

oscillation. Additional terminals are provided for triggering or resetting if desired. In the

time delay mode of operation, the time is precisely controlled by one external resistor and

capacitor. For astable operation as an oscillator, the free running frequency and duty

cycle are accurately controlled with two external resistors and one capacitor. The circuit

may be triggered and reset on falling waveforms, and the output circuit can source or sink

up to 200mA or drive TTL circuits.

Features:

Direct replacement for SE555/NE555

Timing from microseconds through hours

Operates in both astable and monostable modes

Adjustable duty cycle

Output can source or sink 200 mA

Output and supply TTL compatible

Temperature stability better than 0.005% per °C

Normally on and normally off output

Available in 8-pin MSOP package

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Applications:

Precision timing

Pulse generation

Sequential timing

Time delay generation

Pulse width modulation

Pulse position modulation

Linear ramp generator

4.3.4 LTS 542 (7-Segment Display)

Description:

The LTS 542 is a 0.52 inch digit height single digit seven-segment

display. This device utilizes Hi-eff. Red LED chips, which are made from GaAsP

on GaP substrate, and has a red face and red segment.

Fig. 4.6 7 Segment

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Features:

Common Anode

0.52 Inch Digit Height

Continuous Uniform Segments

Low power Requirement

Excellent Characters Appearance

High Brightness & High Contrast

Wide Viewing Angle

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4.3.5 LM7805 (Voltage Regulator)

Fig. 4.7 Voltage Regulator

Description:

The KA78XX/KA78XXA series of three-terminal positive

regulator are available in the TO-220/D-PAK package and with several fixed

output voltages, making them useful in a wide range of applications. Each type

employs internal current limiting, thermal shut down and safe operating area

protection, making it essentially indestructible. If adequate heat sinking is

provided, they can deliver over 1A output current. Although designed primarily as

fixed voltage regulators, these devices can be used with external components to

obtain adjustable voltages and currents.

Features:

Output Current up to 1A

Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V

Thermal Overload Protection

Short Circuit Protection

Output Transistor Safe Operating Area Protection

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4.3.6 RELAY CIRCUIT :

Fig. 4.8 Relay

A single pole dabble throw (SPDT) relay is connected to port RB1 of the

microcontroller through a driver transistor. The relay requires 12 volts at a current

of around 100ma, which cannot provide by the microcontroller. So the driver

transistor is added. The relay is used to operate the external solenoid forming part

of a locking device or for operating any other electrical devices. Normally the

relay remains off. As soon as pin of the microcontroller goes high, the relay

operates. When the relay operates and releases. Diode D2 is the standard diode on

a mechanical relay to prevent back EMF from damaging Q3 when the relay

releases. LED L2 indicates relay on.

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CHAPTER :- 5SOFTWARE DESIGN

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FLOW CHART:

Fig. 4.7 Flow Chart

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Start

Infrared Signal

Transmission

Interrupted from

Sensor1

Interrupted from Sensor

2

Turn On Relay

Counter Increment

ed

Counter Decrement

ed

Counter set to 0

Relay Turn Off

Turn On Light

Turn Off Light

If the sensor 1 is interrupted first then the microcontroller will look for the sensor

2. And if it is interrupted then the microcontroller will increment the count and

switch on the relay, if it is first time interrupted.

If the sensor 2 is interrupted first then the microcontroller will look for the sensor

1. And if it is interrupted then the microcontroller will decrement the count.

When the last person leaves the room then counter goes to 0 and that time the

relay will turn off. And light will be turn off.

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CHAPTER :- 6TESTING AND RESULTS

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Testing And Results

We started our project by making power supply. That is easy for me but when we turn

toward the main circuit, there are many problems and issues related to it, which we faced, like

component selection, which components is better than other and its feature and cost wise a We

started our project by making power supply. That is easy for me but when I turn toward the main

circuit, there are many problems and issues related to it, which are I faced, like component

selection, which components is better than other and its feature and cost wise also, then refer the

data books and other materials related to its.

I had issues with better or correct result, which I desired. And also the software problem.

I also had some soldering issues which were resolved using continuity checks performed

on the hardware.

We had issues with better or correct result, which we desired. And also the software

problem.

We also had some soldering issues which were resolved using continuity checks

performed on the hardware.

We started testing the circuit from the power supply. There we got over first trouble.

After getting 9V from the transformer it was not converted to 5V and the circuit received 9V.

As the solder was shorted IC 7805 got burnt. So we replaced the IC7805.also the circuit

part around the IC7805 were completely damaged..with the help of the solder we made the

necessary paths.

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CHAPTER :- 7FUTURE EXPANSION

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FUTURE EXPANSION

By using this circuit and proper power supply we can implement various applications

Such as fans, tube lights, etc.

By modifying this circuit and using two relays we can achieve a task of opening and

closing the door.

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CHAPTER :- 8APPLICATION, ADVANTAGES &

DISADVANTAGES

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APPLICATION, ADVANTAGES & DISADVANTAGES

Application

o For counting purposes

o For automatic room light control

Advantages

o Low cost

o Easy to use

o Implement in single door

Disadvantages

o It is used only when one single person cuts the rays of the sensor hence it

cannot be used when two person cross simultaneously.

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CHAPTER :- 8BIBILOGRAPHY

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Bibliography

Reference Books

Programming in ANSI C: E BALAGURUSAMY

The 8051microcontroller and embedded systems: MUHAMMAD ALI MAZIDI

JANICE GILLISPIE MAZIDI

The 8051 microcontroller: KENNETH J. AYALA

Website

www.datasheets4u.com

www.8051.com

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