NSS COLLEGE OF ENGINEERING

PALAKKAD, KERALA – 678 008

Mini Project report on

AUTOMATIC ROOM LIGHT CONTROL WITH VISITORS COUNTING

Guided By: Project team:

Mrs.ANJALI.S.NAIR ASWATHY.K

LECTURER KARTHIKA.M.MENON

Dept. I & C NEETHU.K

KARTHIK.S

ANEESH BABU.S

DEPARTMENT OF INSTRUMENTATION AND CONTROL ENGINEERING 2011

NSS COLLEGE OF ENGINEERING

PALAKKAD-678 008

DEPT. OF INSTRUMENTATION AND CONTROL ENGINEERING

CERTIFICATE

This is to certify that this is the bonafide record of the mini project report titled “AUTOMATIC ROOM LIGHT CONTROL WITH VISITORS

COUNTING” done by ASWATHY.K , KARTHIKA.M.MENON ,

NEETHU.K , KARTHIK.S , ANEESH BABU.S in the partialfulfilment of the requirement s for the award of Bachelor of Technology (B.Tech) in instrumentation and control engineering in the year 2011 as a part of their curriculum.

Guided By: Staff in charge Head of

the Dept.: Mrs.Anjali.S.Nair Shri.Anish.M.N Dr.Sitalekshmi Amma Lecturer Lecturer( SS)

ACKNOWLEDGEMENT

We express our sincere gratitude to our guide Mrs.Anjali.S.Nair,Lecturer, Department of Instrumentation and Control, for constantly urging us to come with innovative ideas and also for her valuable guidance and encouragement for the fulfilment of the Mini project.

We would like to take this opportunity to thank Mr.Anish.M.N , Lecturer( SS) ,Dept. of Instrumentation and Control ,our mini project in charge for his cooperation and support for helping us complete this successfully in time.

We also express sincere feelings of gratitude for Dr.B.Sitalekshmi Amma , Head of the Department , Instrumentation and Control , all our teachers who patiently cleared our queries and provided us with valid assistance.

We are thankful to our friends for their whole-hearted cooperation during the preparation & presentation of the mini project. Last but not the least we wish to express our gratitude to God Almighty for his abundant blessings without which

this mini project would not be successful.

ASWATHY.K

KARTHIKA.M.MENON

NEETHU.K

KARTHIK.S

ANEESH BABU.S

ABSTRACT

Project title is “AUTOMATIC ROOM LIGHT CONTROL WITH

VISITOR COUNTING “

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.

CONTENTS

INTRODUCTION BLOCK DIAGRAM AND DESCRIPTION COMPONENT LIST CIRCUIT DIAGRAM CIRCUIT EXPLANATION FLOW CHART PROGRAMMING THE MICROCONTROLLER PCB LAYOUT ESTIMATED COST DATA SHEETS CONCLUSION BIBLIOGRAPHY

INTRODUCTION

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 AT89C52 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

BLOCK DIAGRAM AND DESCRIPTION

EXIT

ENTER

Signal Conditioning

Enter Sensor

Exit Sensor

Power Supply

Signal Conditioning

A

T

8

9

C

5

2

Light

Relay Driver

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.

Power Supply

Entry and Exit sensor circuit

AT 89c52 micro-controller

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 Infrared sensors.By using this sensor and its related circuit

diagram we can count the persons.

3. 89C52 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 AT89C52 is a powerful

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

AT89C52 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.

COMPONENT LIST

1. MICROCONTROLLER-AT89C522. IN4007 DIODES3. CAPACITORS4. TSOP IR SENSORS5. IR TRANSMITTERS6. TRANSISTORS7. RESISTORS8. VOLTAGE REGULATOR 78059. 555 TIMERS10.SEVEN SEGMENT DISPLAY11.RELAY12.TRANSFORMER13.CRYSTAL OSCILLATOR14.POT15.LED

CIRCUIT DIAGRAM

CIRCUIT EXPLANATION

CIRCUIT DESCRIPTION:

There are two main parts of the circuits.

1. Transmission Circuits (Infrared LEDs)

2. Receiver Circuit (Sensors)

1. Transmission Circuit:

Transmitter circuit

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

Astable multivibrator. Here pin 7 of discharging transistor Q1 is connected to the

junction of R1 and R3. When the power supply Vcc is connected,the external

timing capacitor charges towards Vcc with a time constant(R1+R3)C.During this

time the output is high.When the capacitor voltage is equal to 2/3Vcc, transistor Q1

will be on and capacitor begins to discharge through R3 and transistor Q1 with a

time constant R3C. The output will be low at that time. During the discharge of

timing capacitor, as it reaches 1/3Vcc, the situation will inverse that is capacitor

begins to charge again.

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.

2.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. 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'.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.

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.

FLOW CHART

PROGRAMMING THE MICROCONTROLLER

void table();

StartInfrared Signal

TransmissionInterrup

ted from Sensor1

Interrupted from Sensor 2

Turn On

RelayCounte

r Incremented

Counter Decremented

Counter set to 0

Relay Turn Off

Turn On

Light

Turn Off

Light

void display();void hex_to_decimal();unsigned char count,x,y,hund,ten,one,temp,i,z;void main(){

P0 = 0X01; // CLEAR DISPLAY P0.F7 =1; //DISPLAY CTRL M P2.F6=1; //DISPLAY CTRL L P1 = 0XFF; //P1.0 & P1.1 INPUT P2.F7 =0; //LIGHT delay_ms(1000); count=0; i=count; hex_to_decimal(); delay_ms(1000); delay_ms(1000); delay_ms(1000);

//---------------------------------------------------------------------- while(1){ if(count <1){ p2_7_bit=0; } else { p2_7_bit=1; } display(); if(p1_0_bit==0){ delay_ms(10); while(p1_1_bit==1){ delay_ms(2); display(); } count++; if(count > 99)count =0; i = count; hex_to_decimal(); while(p1_0_bit==0){ delay_ms(10); display(); } while(p1_1_bit==0){ delay_ms(10); display(); } for(z=0;z<100;z++) display(); }

//********************************************************************** if(p1_1_bit==0){ delay_ms(10); while(p1_0_bit==1){ delay_ms(2); display(); }

if(count < 1)count =1; count--; i = count; hex_to_decimal(); while(p1_1_bit==0){ delay_ms(10); display(); } while(p1_0_bit==0){ delay_ms(10); display(); } for(z=0;z<100;z++) display(); }

} }

//----------------------------------------------------------------------------//-----------subroutine-------------------------------------------------------//---------------------------------------------------------------------------void hex_to_decimal(){

hund=i/100; temp=i%100; i=temp; ten=i/10; one=temp%10;x=ten;table();ten=y;;

x=one;table();one=y;

}

void table(){if(x ==0)y=1;

if(x==1)y=103;if(x==2)y=18;if(x==3)y=34;if(x==4)y=100;if(x==5)y=40;if(x==6)y=8;if(x==7)y=99;if(x==8)y=0;if(x==9)y=32;}void display(){p2_6_bit=0;p0 =ten;p0_7_bit=1;delay_us(400);p0_7_bit=0;p0 =one;p2_6_bit=1;delay_us(400);}

PCB LAYOUT

ESTIMATED COST

1. 89C52 MICROCONTROLLER Rs 602. SEVEN SEGMENT(2) Rs 203. 555 TIMER(4) Rs 204. TSOP IR SENSOR(2) Rs 365. POT(4.7K)2 Rs 46. TRANSFORMER(12V/500mA) Rs557. IC 7805 VOLTAGE REGULATOR Rs88. CRYSTAL (11.05MHz) Rs109. RELAY(12V) Rs1010.CAPACITORS(15) Rs1811.IN4007 DIODE(4) Rs212.TRANSISTORS(6) Rs2313.RESISTANCES(24) Rs3614.IC BASE(5) Rs1615.AC WIRE Rs1516.2PIN WIRE CONNECTION(4) Rs2017.IR LED(2) Rs618.PCB Rs500 19.LED(4) Rs 4

TOTAL RS 863

DATA SHEETS

TSOP1738 (INFRARED SENSOR)

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

Block Diagram:

Block Diagram of TSOP 1738

Application Circuit:

LTS 542 (7-Segment Display)

Description:

A seven-segment display may have 7, 8, or 9 leads on the chip. Usually leads 8 and 9 are decimal points. The figure below is a typical component and pin layout for a seven segment display.

Features:

Common Anode

0.52 Inch Digit Height

Continuous Uniform Segments

Low power Requirement

Excellent Characters Appearance

High Brightness & High Contrast

Wide Viewing Angle

Voltage Regulator 7805

The Digilab board can use any power supply that creates a DC voltage between

6and 12 volts. A 5V voltage regulator (7805) is used to ensure that no more than

5V is delivered to the Digilab board regardless of the voltage present at the J12

connector (provided that voltage is less than 12VDC). The regulator functions by

using a diode to clamp the output voltage at 5VDC regardless of the input voltage -

excess voltage is converted to heat and dissipated through the body of the

regulator. If a DC supply of greater than 12V is used, excessive heat will be

generated, and the board may be damaged. If a DC supply of less than 5V is used,

insufficient voltage will be present at the regulators output.

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

RELAY CIRCUIT:

Relay

A single pole double 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.

555 TIMER IC

The 555 timer IC is an integrated circuit chip used in a variety of timer, pulse

generation and oscillator applications. The IC design was proposed in 1970 by

Hans R. Camenzind and Jim Ball. After prototyping, the design was ported to the

Monochip analogue array, incorporating detailed design by Wayne Foletta and

others from Qualidyne Semiconductors. Signe tics (later acquired by Philips) took

over the design and production, and released the first 555s in 1971. The full part

numbers were NE555 (commercial temperature range, 0 °C to +70 °C) and SE555

(military temperature range, −55 °C to +125 °C). As with most parts of the era,

these were available in both high-reliability metal can (T package) and inexpensive

epoxy plastic (V package) packages. Thus the full part numbers were NE555V,

NE555T, SE555V, and SE555T. It has been hypothesized that the 555 got its name

from the three 5 kΩ resistors used within .The part is still in widespread use,

thanks to its ease of use, low price and good stability. As of 2003, it is estimated

that 1 billion units are manufactured every year. The circuit arrangement of the 555

is said to be even more common, being incorporated in the charge pump of many

single-voltage Flash and other electrically-erasable ICs.

Depending on the manufacturer, the standard 555 package includes over 20

transistors, 2 diodes and 15 resistors on a silicon chip installed in an 8-pin mini

dual-in-line package (DIP-8)

The 555 has three operating modes:

Monostable mode: in this mode, the 555 functions as a "one-shot" pulse

generator. Applications include timers, missing pulse detection, bounce free

switches, touch switches, frequency divider, capacitance measurement,

pulse-width modulation (PWM)

Astable – free running mode: the 555 can operate as an oscillator. Uses

include LED and lamp flashers, pulse generation, logic clocks, tone

generation, security alarms, pulse position modulation and so on.

Bistable mode or Schmitt trigger: the 555 can operate as a flip-flop, if the

DIS pin is not connected and no capacitor is used. Uses include bounce free

latched switches.

USAGE

The connection of the pins is as follows:

PIN NAME PURPOSE1. GND Ground, low level (0 V)

2. TRIG OUT rises, and interval starts, when this input falls below 1/3 VCC.

3. OUT This output is driven to + V CC or GND.

4. RESET A timing interval may be interrupted by driving this input to GND.

5. CTRL "Control" access to the internal voltage divider (by default, 2/3 VCC).

6. THR The interval ends when the voltage at THR is greater than at CTRL.

7. DIS Open collector output; may discharge a capacitor between intervals.

8. V+, VCC Positive supply voltage is usually between 3 and 15 V.

MONOSTABLE MODE

In the monostable mode, the 555 timer acts as a “one-shot” pulse generator. The

pulse begins when the 555 timer receives a signal at the trigger input that falls

below a third of the voltage supply. The width of the output pulse is determined by

the time constant of an RC network, which consists of a capacitor (C) and a

resistor (R). The output pulse ends when the charge on the C equals 2/3 of the

supply voltage. The output pulse width can be lengthened or shortened to the need

of the specific application by adjusting the values of R and C. The output pulse

width of time t, which is the time it takes to charge C to 2/3 of the supply voltage,

is given by

Where t is in seconds, R is in ohms and C is in farads.

Astable mode

In astable mode, the 555 timer puts out a continuous stream of rectangular pulses

having a specified frequency. Resistor R1 is connected between VCC and the

discharge pin (pin 7) and another resistor (R2) is connected between the discharge

pin (pin 7), and the trigger (pin 2) and threshold (pin 6) pins that share a common

node. Hence the capacitor is charged through R1 and R2, and discharged only

through R2, since pin 7 has low impedance to ground during output low intervals of

the cycle, therefore discharging the capacitor.

In the astable mode, the frequency of the pulse stream depends on the values of R1,

R2 and C:

The high time from each pulse is given by

And the low time from each pulse is given by

Where R1 and R2 are the values of the resistors in ohms and C is the value of the

capacitor in farads.

To achieve a duty cycle of less than 50% a diode can be added in parallel with R2

towards the capacitor. This bypasses R2 during the high part of the cycle so that the

high interval depends only on R1 and C.

BISTABLE MODE

In bistable mode, the 555 timer acts as a basic flip-flop. The trigger and reset

inputs (pins 2 and 4 respectively on a 555) are held high via Pull-up resistors

while the threshold input (pin 6) is simply grounded. Thus configured, pulling the

trigger momentarily to ground acts as a 'set' and transitions the output pin (pin 3) to

Vcc (high state). Pulling the reset input to ground acts as a 'reset' and transitions

the output pin to ground (low state). No capacitors are required in a bistable

configuration. Pins 5 and 7 (control and discharge) are left floating.

SPECIFICATIONS

These specifications apply to the NE555. Other 555 timers can have different

specifications depending on the grade (military, medical, etc).

Supply voltage (VCC) 4.5 to 15 V

Supply current (VCC = +5 V) 3 to 6 mA

Supply current (VCC = +15 V) 10 to 15 mA

Output current (maximum) 200 mA

Maximum Power dissipation 600 mW

Power Consumption (minimum operating) 30 mW@5V, 225 mW@15V

Operating temperature 0 to 70 °C

CONCLUSION

The cicuit has been soldered to the PCB and found to be working. 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. This circuit is used for

counting purposes and for automatic room light control. Advantages of this

circuit are Low cost , Easy to use, can implement in single door. The main

drawback of this cicuit is , it is used only when one single person cuts the rays of

the sensor hence it cannot be used when two person cross simultaneously.

BIBLIOGRAPHY

1. 8051 Microcontroller and embedded Design – Kenneth J Ayala 2. www.8051.com 3. www.atmel.com 4. www.keilsoftware.com 5. Programming in ANSI C: E BALAGURUSAMY

6. The 8051microcontroller and embedded systems: MUHAMMAD ALI MAZIDI

JANICE GILLISPIE MAZIDI