Smart Home Security System Based On GSM Technology ...

Visvesvaraya Technological University Jnana Sangama, Machhe, Belgaum, Karnataka - 590014

Project Report On

Design and Implementation of Security Systems For

Smart Home Based on GSM Technology

Submitted in partial fulfillment of the requirements for the award of degree

Bachelor Of Engineering

In

Electronics and Communication Engineering

Submitted By

Ankit Yadav : 1NH13EC709

M.Jeevan Kishore : 1NH13EC727

Shubham Mishra : 1NH13EC754

Under the guidance of

Ms. M.Maheswari

Senior Assistant Professor

Dept. of ECE,NHCE

Outer Ring Road, Panathur post, Kadubisanahalli, Bangalore – 560103 Department of

Electronics and Communication Engineering – 2017.

CERTIFICATE

Certified that the project work entitled “Design And Implementation Of Security Systems

For Smart Home Based On Gsm Technology” carried out by Mr.Ankit Yadav

(1NH13EC709), Mr.M.Jeevan Kishore (1NH13EC727) and Mr.Shubham Mishra

(1NH13EC754), a bonafide students of 8th semester in partial fulfillment for the award of

Bachelor of Engineering in ELECTRONICS AND COMMUNICATION branch of the

Visvesvaraya Technological University, Belagavi during the year 2016 – 2017. It is certified

that all corrections/ suggestions indicated for Internal Assessment have been incorporated in

the report deposited in the department library. The project report has been approved as it

satisfies the academic requirements in respect of project work prescribed for said Degree.

Name & Signature of the Name & Signature of the Name & Signature of the

Guide HOD Principal

Ms. M.Maheswari Dr. Sanjay Jain Dr. Manjunatha

External Viva

Name of the examiners Signature with date

1)

2)

DECLARATION

We, hereby declare that this dissertation work entitled “Design And Implementation Of

Security Systems For Smart Home Based On Gsm Technology” was carried out by us

as a team under the guidance and supervision of Ms.M.Maheswari, Senior Assistant

Professor Department of Electronics and Communication Engineering, New Horizon

College of Engineering, Bengaluru-560103.

This project work is submitted to Visvesvaraya Technological University, Belagavi,

Karnataka in partial fulfilment of the requirement for the award of Bachelor of

Engineering in Electronics and Communication Engineering during the academic year

2016-2017. Further, the matter embodied in the dissertation has not been submitted

previously by anybody for the award of any degree or diploma to any other university.

Name and USN numbers: Signature

ANKIT YADAV - 1NH13EC709

M.JEEVAN KISHORE - 1NH13EC727

SHUBHAM MISHRA - 1NH13EC754

ABSTRACT

Security has become an important issue everywhere. Home security is becoming

necessary nowadays as the possibilities of intrusion are increasing day by day. Safety

from theft, leaking of raw gas and fire are the most important requirements of home

security system for people. A traditional home security system gives the signals in terms

of alarm. However, the GSM (Global System for Mobile communications) based security

systems provides enhanced security as whenever a signal from sensor occurs, a text

message is sent to a desired number to take necessary actions.

In this home security system, the system sends SMS to the user which uses GSM-GPS

Module (sim800) and Atmega328p microcontroller, sensors, relays and buzzers.

ACKNOWLEDGEMENT

The satisfaction that accompanies the successful completion of any task would be

incomplete without due reverence given to those who made it possible, whose constant

guidance and encouragement crowned our efforts with success.

Firstly, we would like to express thanks to our college which has given us this

opportunity to work on this project.

We convey our sincere gratitude to Dr. Manjunatha, Principal, NHCE, Bangalore for

facilities provided in college and for the support in numerous ways.

We remain indebted to Dr. Sanjay Jain, HOD, Department of E&C, NHCE for

providing us permission to take up the project work.

We would like to express our profound gratitude to our internal guide Ms.M.Maheswari,

Senior Assistant Professor, Department of E&C, NHCE.

We would like to express our deepest sense of gratitude to our parents and friends who

have been a great source of moral support, courage, for giving us a helping hand and

making us go smiles with their lovable presence during our tough times and relieving us

from stress throughout our project endeavor.

i

TABLE OF CONTENTS

CHAPTER 1 : INTRODUCTION 1

1.1 Motivation 2

1.2 Aim of the project 3

1.3 Block diagram 4

1.4 Requirements 5

1.4.1 Hardware specifications 5

1.4.2 Software specifications 5

CHAPTER 2 : LITERATURE SURVEY 6

2.1 Security Systems 6

2.2 History of Smart homes 7

CHAPTER 3 : Arduino Uno 9

3.1 Introduction of Arduino Uno 9

3.2 Physical Characteristics 11

3.3 Features of Arduino Uno 11

CHAPTER 4 : MICROCONTROLLER 12

4.1 Specifications 12

4.2 Key parameters 13

4.3 Applications 14

CHAPTER 5 : PIR SENSOR 15

5.1 Pyroelectric Sensor 15

5.1.1 Working of PIR 15

5.2 Fresnel lens in PIR 17

5.3 Pins of PIR 18

5.4 Features and Electrical Specification 19

ii

5.5 Areas of Applications 19

CHAPTER 6 : TEMPERATURE/HUMIDITY SENSOR 20

6.1 Relative Humidity 20

6.2 How the DHT11 Measures Humidity and Temperature? 21

6.3 Ranges and Accuracy of the DHT11 23

6.4 Areas of Applications 23

CHAPTER 7 : SMOKE SENSOR 24

7.1 MQ2 Gas sensor 24

7.2 Pins of MQ2 sensor 25

7.3 Working of MQ2 26


CHAPTER 8 : LDR( Light dependant Resistor) 28

8.1 Introduction to LDR 28

8.2 Working principle of LDR 29

8.3 Specifications of LDR 29

CHAPTER 9 : LPG Gas Sensor - MQ-6 30

9.2 Pins of MQ6 31

9.3 SPECIFICATIONS 31

9.4 Features 32

9.5 Main Applications 32

CHAPTER 10 : LIQUID CRYTAL DISPLAY(LCD) 33

10.1 Introduction 33

10.2 Pin Description 34

10.3 Lcd Command Codes 36

iii

CHAPTER 11 : GSM MODULE 37

11.1 Introduction to GSM Module: 37


11.3 Basic Commands Of Gsm Module 39

CHAPTER 12 : IMPLEMENTED CODE 41

12.1 Algorithm 41

12.2 Code 42

CHAPTER 13 : CONCLUSION 49

12.1 Result 49

12.2 Future work 50

REFERENCES 51

iv

LIST OF TABLES & FIGURES

CHAPTER 1 : INTRODUCTION 1

Figure 1.1 : Smart Home 1

Figure 1.3 : Block Diagram 4

CHAPTER 3 : Arduino Uno 9

Figure 3.1 : Arduino R3 board 10

Table 3.1 : Features of Arduino Uno 11

CHAPTER 4 : MICROCONTROLLER 12

Figure 4.1 : Atmega 328p 12

Figure 4.2 : Arduino pin mapping 13

Table 4.1 : Key parameters 14

CHAPTER 5 : PIR SENSOR 15

Figure 5.1 : PIR Sensor 15

Figure 5.2 : Working of PIR 15

Figure 5.3 : Working of Fresnel lens 17

Figure 5.4 : Fresnel lens 18

Figure 5.5 : Pin diagram of PIR 18

CHAPTER 6 : TEMPERATURE/HUMIDITY SENSOR 20

Figure 6.1 : Components in DHT11 22

Figure 6.2 : Pin diagram of DHT11 22

Figure 6.3 : Variation of resistance wrt temp

23

CHAPTER 7 : SMOKE SENSOR 24

Figure 7.1 : MQ2 Gas sensor 25

Figure 7.2 : Pins of MQ2 sensor 26

v

Figure 7.3 : Working of MQ2 27

Table 7.1 : Specification of MQ2 sensors 27

CHAPTER 8 : LDR( Light dependant Resistor) 28

Figure 8.1 : Introduction to LDR 28

CHAPTER 9 : LPG Gas Sensor - MQ-6 30

Figure 9.1 : MQ6 Sensors 30

Figure 9.2 : Pin diagram of MQ6 31

Table 9.1 : Features of MQ6 32

CHAPTER 10 : LIQUID CRYTAL DISPLAY(LCD) 33

Figure 10.1 : 16 X 2 LCD display 33

Figure 10.2 : LCD pin diagram 34

Table 10.1 : Pin description 35

Table 10.2 : Lcd Command Codes

36

CHAPTER 11 : GSM MODULE 37

Figure 11.1 : Image of GSM Module: 37

Figure 11.2 : Block diagram 38

Figure 11.3 : Pin diagram of GSM Module 38

Smart Home Security System Based On GSM Technology 2016-17

Department Of Electronics And Communication, NHCE Page 1

CHAPTER 1

INTRODUCTION

Smart homes cleverly merge your family's lifestyle with the latest technology & energy

management tools to make your life easier. Home automation or smart home (also known

as domotics) is building automation for the home. It involves the control and automation

of lighting, heating (such as smart thermostats), ventilation, air conditioning (HVAC),

and security, as well as home appliances such as washer/dryers, ovens or

refrigerators/freezers.

Fig 1.1 Smart home



1.1 Motivation

The motivation for developing smart home systems comes from many reasons, but most

prominent are convenience, security, energy management, connectivity and luxury. Smart

Home systems are one of the newer areas of research that have not been fully integrated

into our society. This is because the research requires many other disciplines of research

and engineering to produce a functional smart home. The technology is becoming better

and cheaper, and this will help to make smart home systems an expense worth having

when new homes are being built.

The biggest motivation behind smart home systems is the convenience. Convenience is

really another way of saying “time saver”, and into day’s world where everything is

moving faster, every second has value. Most of the technology we use today is based of

convenience, for example cars get us where we need to go faster, phones get us

information from other people faster, and computer’s get work done faster. Smaller

conveniences in the home will be desirable because they allow the home to save the user

time as well. A Smart home systems goal is to introduce the benefits of computerized

technology. For example, when using the smart home system, the user will not need to

walk around turning off lights, they can save that little bit of extra time by just moving

out of the room, or even have the lights programmed to shut off after a certain amount of

time. There are many other small conveniences provided from the smart home.

Security is also a big factor in the emergence of smart home systems. With a sophisticated

enough system, home security becomes a powerful tool that gives piece of mind and

power to the user. Security systems are also a large deterrent for crime. There are already

many security systems on the market available and in use today, however integrating the

security system into the smart home gives the user a one stop access to everything in their

home. If the smart home system integrates the smart phone into the system then this

means that the user will always know the status of the security of their home.

Energy management has become a huge factor in deciding anything, due to the

trend of increasing cost of energy. As civilization grows, it constantly needs more energy



to power itself. This leads to heavy pressure on efficient use of energy. Smart Home

systems help the user do this and save them money at the same time. The smart home

system is able to monitor certain process that use energy in the house and can control the

amount of energy being used. A primary example would be with lights. Lights are often

left on when they don’t need to be. A smart home system can be set to turn that light off

after a certain amount of time

1.2 Aim of the project

This project is trying to develop a design, prototype, and software for multipurpose

control devices in home. The project should be quick to setup, consume low power, and

easy to use. The project uses light sensors, motion sensors, temperature sensors, and gas

& smoke sensors to determine various conditions of the home to provide security

measures and uses a gsm module to notify users. Basic requirements to the design:

• Comfortably in using

• User-friendly interface

• Connectivity using GSM module.



1.3 Block diagram

Fig1.2 Block diagram



1.4 Requirements

1.4.1 Hardware specifications

Atmega328p microcontroller

Gsm module (sim900A)

Mobile phone

Passive Infrared sensor

Gas sensor

Temperature and humidity sensor

smoke sensor

Led’s and buzzers

16x2 LCD

1.4.2 Software specifications

Coding language - Embedded C

Platform used - Arduino IDE



CHAPTER 2

LITERATURE SURVEY

2.1 Security Systems

“The tasks of a modern security system include identifying an intruder trying to

gain access to the home, alerting the homeowner about the intrusion or intrusion attempt,

preventing the intruder from gaining access to the home, and gathering or collecting

evidence regarding the intrusion so that the perpetuators can be brought to justice.” The

advancement of technology has contributed to the changing concept of security in modern

homes. It has changed from a simple lock and key security concept to implementing

sophisticated security systems using cameras, microphones, contact sensors, proximity

sensors, alarms, silent alarms, etc. By connecting modern homes to their phones which is

very popular today, users can access and control their homes remotely at any time and

from anywhere in the world. An increase in processing power of newly-designed

processors and the considerable reduction in power consumption, cost, and size of new

electronics devices enables people to know and control every aspect of their home, like

which door or window is open, which device or light is switched on, and which rooms are

occupied. Inhabitants can keep an eye on their home using live video and audio feeds

from different parts of their home. They can also be aware of different environmental

factors inside and outside their home, like humidity, temperature, and light intensity.

When people think about home automation, most of them may imagine living in a smart

home: One remote controller for every household appliance, cooking the rice

automatically, starting air conditioner automatically, heating water for bath automatically

and shading the window automatically when night coming. To some extent home

automation equals to smart home. They both bring out smart living condition and make

our life more convenient and fast.



people at that time understood that a smart home is not owing to how well it is

built, not how effectively it uses space, not due to how it is environmentally friendly. It is

only because of how interactive technologies that it contains. Those are still useful rules

for home automation technology today.

Home automation satisfies the resident’s needs and desires by adjustable light,

temperature, ambient music, automatic shading, safety & security, even arrangement of

wire. Home automation technologies are the latest fascination with housing mechanism.

However, with the appearance of new electronic technologies and their combination with

older, traditional building technologies, the smart home is at last becoming a reality.

The basic idea of home automation is to monitor a dwelling place by using sensors

and control systems. Through adjustable various mechanisms, user can enjoy customized

heat, ventilation, lighting, and other servers in living condition. The more closely adjust

the entire living mechanical system and loop control system, the intelligent home can

provide a safer, more comfortable, and more energy economical living condition.

2.2 History of Smart homes

Home automation technology and Smart home appeared very much in science fiction of

the 1920s. But no one knows the exact date of the invention of home automation. Based

on human’s smart technology improving process, the home automation system does not

come by immediate invention. It comes step by step with only insignificant improvement.

The previous step is almost same with the next step.

Manufactures of laborsaving appliances have been promising homeowners an automated

“Home of the Future” since the World’s Fair days of the 1930s. The intelligent home has

been a popular vision for a few decades.



From the early 1980s, many Japanese firms published their own home automation

blueprints, developed demonstration houses and launched proprietary systems. These

included major electrical appliance manufacturers such as

Matsushita,Toshiba,Mitsubishi,Sanyo,Sony,and Sharp. Some interphone companies first

added security functions to their systems. Secom, a security services firm, expanded upon

its original security system to develop a central control station for remote control of home

security. The TRON project, which was started in 1984, encompassed more than the other

home automation packages currently under development, being especially concerned with

architecture and the experience of space inside the house. In September 1988, the “Home

Bus System” industry standard was issued.

In US, 1982, AT &T established the concept of “Intelligent Building”. The

Informant Building an office building and conference center in Dallas which promoted a

good sense of community among tenants and customers, was erected to demonstrate how

advanced IT from different suppliers could be used in the intelligent building.

The Smart House Project was established in 1984 as project of the National

Research Center of the National Association of Home Builders (NAHB), USA, with the

cooperation of a number of major industrial partners. NAHB formed the SMART

HOUSE Limited Partnership (L.P.).It sought the participation of several manufactures for

every major type of hardware that would be needed for Smart House systems.

The breakthrough in home automation, which emerged tentatively in 2001, saw

the Van Berlos employ staff for Smart Homes for the first time and build The Smartest

Home of the Netherlands. Through cooperation with many participants, to whom Smart

Homes is very grateful, the significantly renewed demonstration home was opened in

Tilburg at the end of 2001. The exceptional thing about this completely inhabitable home

is the integration of the four pillars: industrial, flexible and demountable (IFD) building,

home automation, durability, and accessibility. The home has already attracted many

thousands of visitors in Tilburg, Almere, Duiven, Heerlen, Dokkum, Amsterdam, and

Eindhoven.



CHAPTER 3

Arduino Uno

3.1 Introduction of Arduino Uno

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 16MHz

ceramic resonator, USB connection, a power jack, an ICSP header and a reset button. It

contains everything needed to support the microcontroller; simply connect it to computer

with a USB cable or power it with a AC-to-DC adapter or battery to get started. The Uno

differs from all preceding boards in that it does not use the FTDI USB-to-serial driver

chip. Instead, it features the Atmega16U2 programmed as a USB-to-serial converter.

Changes in Uno R3

1. Pin out: added SDA and SCL pins that are near to the AREF pin and two other new

pins placed near to the reset pin, the IOREF that allow the shields to adapt to the voltage

provided from the board. In future, shields will be compatible with both the board that

uses the AVR, which operates with 5v and with the Arduino due that operates with 3.3V.

2. Stronger RESET circuit.

3. ATmega16U2 replace the 8U2.

"Uno" means one in Italian and is named to mark the upcoming release of Arduino 1.0.

The Uno and version 1.0 will be the reference versions of Arduino, moving forward. The

Uno is the latest in a series of USB Arduino boards, and the reference model for the

Arduino platform; for a comparison with previous versions, see the index of

ArduinoBoards.



Fig 3.1 Arduino R3 board

Each of the 14 digital pins on the Uno can be used as an input or output, using PinMode(),

digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide

or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by

default) of 20-50 kOhms.

In addition, some pins have specialized functions:

• Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data.

These pins are connected to the corresponding pins of the ATmega8U2 USB-to-TTL

Serial chip

• External Interrupts: 2 and 3. These pins can be configured to trigger an interrupt on a

lowvalue, a rising or falling edge, or a change in value. See the attach Interrupt() function

for details.

• PWM: 3, 5, 6, 9, 10, and 11. Provide 8-bit PWM output with the analogWrite() function.

• SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI

communication,which, although provided by the underlying hardware,is not currently

included in the Arduino language.

• LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH

value, the LED is on, when the pin is LOW, it's off.



3.2 Physical Characteristics

The maximum length and width of the Uno PCB are 2.7 and 2.1 inches respectively, with

the USB connector and power jack extending beyond the former dimension. Three screw

holes allow the board to be attached to a surface or case. Note that the distance between

digital pins 7 and 8 is 160 mil (0.16"), not an even multiple of the 100 mil spacing of the

other pins

3.3 Features of Arduino Uno

MICROCONTROLLER ATmega328P

Operating voltage 5V

Input Voltage (recommended) 7-12V

Input Voltage (limit) 6-20V

Digital I/O pins 14 (of which 6 provide PWM output)

PWM Digital I/O Pins 6

Analog Input Pins 6

DC Current per I/O Pin 20mA

DC Current for 3.3V PIN 50 mA

Flash Memory 32KB (ATmega328P)

Of which 0.5 KB used by boot loader

SRAM 2 KB (ATmega328P)

EEPROM 1 KB (ATmega328P)

Clock speed 16 Mhz

Length 68.6 mm

Width 53.4 mm

Weight 25g

Table 3.1 features of Aurdino uno



CHAPTER 4

MICROCONTROLLER

TheATmega328pis a single-chip microcontroller created by Atmel in the megaAVR

family.

4.1 Specifications

The Atmel l8-bitAVR RISC-based microcontroller combines 32kB ISP flash memory

with read-while-write capabilities, 1kB EEPROM, 2kB SRAM, 23 general purpose I/O

lines, 32 general purpose working registers, three flexible timer/counters with compare

modes, internal and external interrupts, serial programmable USART, a byte-oriented 2-

wire serial interface,SPI serial port, 6-channel 10-bitA/D converter(8-channels in TQFP

and QFN / MLF packages), programmable watchdog timer with internal oscillator, and

five software selectable power saving modes. The device operates between 1.8-5.5 volts.

The device achieves throughput approaching 1MIPS per MHz.

Fig4.1 Atmega 328p

https://en.wikipedia.org/wiki/Atmel_AVR



Fig4.2 Arduino pin mapping

4.2 Key parameters

Parameter Value

CPU type 8-bit AVR

Performance 20 MIPS at 20 MHz

Flash memory 32 kB

SRAM 2 kB

EEPROM 1 kB



Pin count 28-pin PDIP, MLF, 32-pin TQFP, MLF

Maximum operating frequency 20 MHz

Number of touch channels 16

Hardware QTouch Acquisition No

Maximum I/O pins 26

External interrupts 2

USB Interface No

Table 4.1 Key parameters

4.3 Applications

As of 2017 the ATmega328 is commonly used in many projects and autonomous systems

where a simple, low-powered, low-cost micro-controller is needed. Perhaps the most

common implementation of this chip is on the popular Arduino development platform,

namely the Arduino Uno and Arduino Nano models.



CHAPTER 5

PIR SENSOR

A PIR or a Passive Infrared Sensor can be used to detect presence of human beings in its

proximity. Basically motion detection use light sensors to detect either the presence of

infrared light emitted from a warm object or absence of infrared light when a object

interrupts a beam emitted by another part of the device.

5.1 Pyroelectric Sensor

Fig5.1 PIR sensor



5.1.1 Working of PIR

When a human or animal body will get in the range of the sensor it will detect a

movement because the human or animal body emits heat energy in a form of infrared

radiation.

That’s where the name of the sensor comes from, a Passive Infra-Red sensor. And the

term “passive” means that sensor is not using any energy for detecting purposes, it just

works by detecting the energy given off by the other objects.

Fig 5.2 PIR working



5.2 Fresnel lens in PIR

Fig 5.3 Working of Fresnel lens

The module has just three pins, a Ground and a VCC for powering the module and an

output pin which gives high logic level if an object is detected. Also it has two

potentiometers. One for adjusting the sensitivity of the sensor and the other for adjusting

the time the output signal stays high when object is detected. This time can be adjusted

from 0.3 seconds up to 5 minutes.



Fig 5.4 Fresnel lens

5.3 Pins of PIR

Fig 5.5 Pin diagram of PIR



The module has three more pins with a jumper between two of them. These pins are for

selecting the trigger modes. The first one is called “non-repeatable trigger” and works like this:

when the sensor output is high and the delay time is over, the output will automatically change

from high to low level. The other mode called “repeatable trigger” will keep the output high all

the time until the detected object is present in sensor’s range.

5.4 Features and Electrical Specification

Complete with PIR, Motion Detection IC and Fresnel Lens

Dual Element Sensor with Low Noise and High Sensitivity

Supply Voltage: 5-20Vdc

Delay Time Adjustable: 5 seconds to 18 Minutes

Standard TTL Output

Module Dimensions: 28mm Length, 38mm Width, 40mm Height

5.5 Areas of Applications

All outdoor Lights

Lift Lobby

Multi Apartment Complexes

Common staircases

For Basement or Covered Parking Area

Shopping Malls

For garden lights



CHAPTER 6

TEMPERATURE/HUMIDITY SENSOR

A Temprature/humidity sensor senses,measures and regularly reports the relative

humidity in the air. It measures both moisture and air temperature.Relative humidity,

expressed as a percent, is the ratio of actual moisture in the air to the highest amount of

moisture air at that temperature can hold.The warmer the air is, the more moisture it can

hold, so relative humidity changes with fluctuations in temperature.

6.1 Relative Humidity

The DHT11 measures relative humidity. Relative humidity is the amount of water vapour

in air vs. the saturation point of water vapour in air. At the saturation point, water vapour

starts to condense and accumulate on surfaces forming dew.

The saturation point changes with air temperature. Cold air can hold less water vapour

before it becomes saturated, and hot air can hold more water vapour before it becomes

saturated.

The formula to calculate relative humidity is:

RH=(𝜌𝑤

𝜌𝑠)*100 ……………………………………………………………….(6.1)

RH: Relative Humidity

𝝆w: Density of Water Vapour



𝝆s: Density of Water Vapour at Saturation

Relative humidity is expressed as a percentage. At 100% RH, condensation occurs, and at

0% RH, the air is completely dry.

6.2 How the DHT11 Measures Humidity and Temperature?

The DHT11 detects water vapour by measuring the electrical resistance between two

electrodes. The humidity sensing component is a moisture holding substrate with

electrodes applied to the surface. When water vapour is absorbed by the substrate, ions

are released by the substrate which increases the conductivity between the electrodes. The

change in resistance between the two electrodes is proportional to the relative humidity.

Higher relative humidity decreases the resistance between the electrodes, while lower

relative humidity increases the resistance between the electrodes.

The DHT11 measures temperature with a surface mounted NTC temperature sensor

(thermistor) built into the unit.

With the plastic housing removed, you can see the electrodes applied to the substrate:

An IC mounted on the back of the unit converts the resistance measurement to relative

humidity. It also stores the calibration coefficients, and controls the data signal

transmission between the DHT11 and the Arduino

The DHT11 uses just one signal wire to transmit data to the Arduino. Power comes from

separate 5V and ground wires. A 10K Ohm pull-up resistor is needed between the signal

line and 5V line to make sure the signal level stays high by default (see the datasheet for

more info).



Fig 6.1 Components in DHT11

There are two different versions of the DHT11 you might come across. One type has four

pins, and the other type has three pins and is mounted to a small PCB. The PCB mounted

version is nice because it includes a surface mounted 10K Ohm pull up resistor for the

signal line. Here are the pin outs for both versions:

Fig 6.2 Pin diagram of DHT11



Fig 6.3 Variation in resistance wrt temp

6.3 Ranges and Accuracy of the DHT11

Humidity Range: 20-90% RH

Humidity Accuracy: ±5% RH

Temperature Range: 0-50 °C

Temperature Accuracy: ±2% °C

Operating Voltage: 3V to 5.5

6.4 Areas of Applications

Measurement of temperature in a room

Temperature sensors in applications for renewable resources

Temperature sensors for heat pumps

Temperature sensors for rail vehicles



CHAPTER 7

SMOKE SENSOR

In current technology scenario, monitoring of gases produced is very important. From

home appliances such as air conditioners to electric chimneys and safety systems at

industries monitoring of gases is very crucial. Gas sensors are very important part of such

systems. Small like a nose, gas sensors spontaneously react to the gas present, thus

keeping the system updated about any alterations that occur in the concentration of

molecules at gaseous state.

Gas sensors are available in wide specifications depending on the sensitivity levels, type

of gas to be sensed, physical dimensions and numerous other factors. This Insight covers

a methane gas sensor that can sense gases such as ammonia which might get produced

from methane. When a gas interacts with this sensor, it is first ionized into its constituents

and is then adsorbed by the sensing element. This adsorption creates a potential difference

on the element which is conveyed to the processor unit through output pins in form of

current. What is this sensing element? Is it kept in some chamber or is kept exposed?

How does it get current and how it is taken out? .

7.1 MQ2 Gas sensor

The gas sensor module MQ2 consists of a steel exoskeleton under which a sensing

element is housed. This sensing element is subjected to current through connecting leads.

This current is known as heating current through it, the gases coming close to the sensing

element get ionized and are absorbed by the sensing element. This changes the resistance

of the sensing element which alters the value of the current going out of it.



Fig 7.1 MQ2 gas sensor

7.2 Pins of MQ2 sensor

The enveloped MQ-2 have 6 pin, 4of them are used to fetch signals, and other 2 are used

for providing heating current.

Pin-------------------------------------Wiring to Arduino uno

A0-------------------------------------Analog pins

D0-------------------------------------Digital pins

GND-----------------------------------GND

VCC------------------------------------5V



Fig 7.2 Pins of MQ2

7.3 Working of MQ2

The voltage that the sensor outputs changes accordingly to the smoke/gas level that

exists in the atmosphere. The sensor outputs a voltage that is proportional to the

concentration of smoke/gas.

In other words, the relationship between voltage and gas concentration is the

following:

The greater the gas concentration, the greater the output voltage

The lower the gas concentration, the lower the output voltage



Fig 7.3 Working of MQ2

7.4 Specifications

ITEM PARAMETER MIN TYPICAL MAX UNIT

VCC Working Voltage 4.9 5 5.1 V

PH Heating

Consumption

0.5 _ 800 MV

RL Load Restistance _ 33 _ ohm

RH Heat Resistance _ 33 _ ohm

RS Sensing Resistance 3 _ 30 kiloohm

Table 7.1 Specification of MQ2 sensors



CHAPTER 8

LDR( Light dependant Resistor)

8.1 Introduction to LDR

A photo resistor or light-dependent resistor (LDR) or photocell is a light-controlled

variable resistor. The resistance of a photo resistor decreases with increasing incident

light intensity; in other words, it exhibits photoconductivity.

Fig 8.1 LDR



8.2 Working principle of LDR

A light dependent resistor works on the principle of photo conductivity. Photo

conductivity is an optical phenomenon in which the materials conductivity is increased

when light is absorbed by the material.

When light falls i.e. when the photons fall on the device, the electrons in the valence band

of the semiconductor material are excited to the conduction band. These photons in the

incident light should have energy greater than the band gap of the semiconductor material

to make the electrons jump from the valence band to the conduction band. Hence when

light having enough energy strikes on the device, more and more electrons are excited to

the conduction band which results in large number of charge carriers, resulting free

electrons (and their hole partners) conduct electricity, thereby lowering resistance. This is

the most common working principle of LDR.

8.3 Specifications of LDR

1) Operating Voltage: 3.3V to 5V DC

2) Operating Current: 15ma

3) Output Digital - 0V to 5V, Adjustable trigger level from preset

4) Output Analog - 0V to 5V based on light falling on the LDR

5) LEDs indicating output and power

6) LM393 based design

https://en.wikipedia.org/wiki/Electron_hole

https://en.wikipedia.org/wiki/Electrical_resistance



CHAPTER 9

LPG Gas Sensor - MQ-6

This is a simple-to-use liquefied petroleum gas (LPG) sensor, suitable for sensing LPG

(composed of mostly propane and butane) concentrations in the air. The MQ-6 can detect

gas concentrations anywhere from 200 to 10000ppm.

This sensor has a high sensitivity and fast response time. The sensor’s output is an analog

resistance. The drive circuit is very simple; all you need to do is power the heater coil

with 5V, add a load resistance, and connect the output to an ADC.

Fig 9.1 MQ6 Sensor

.9.1 DESCRIPTION

This is a very easy to use and very handy gas sensor, suitable for sensing LPG gas

concentration. This sensor MQ6 can detect Carbon monooxide gas concentrations

anywhere from 20 to 2000ppm. The MQ-6 sensor has a very sensitivity to Carbon mono

oxide gas. The sensitive material of MQ-6isSnO2, which has lower conductivity in

cleanair. When he targetsLPG gas exist, the sensor’s conductivity is higher along with the

gas concentration rising.MQ6sensor has highsensitivity to Propane, Butane and LPG gas,

and good resistance to disturb of gasoline, smoke and vapour. The sensor could be used to



detect LPG with different concentration, it is with low cost and suitable for

different application.

This sensor has a very simple; all you need to do is power the heater coil with 5V, add a

load resistance, and connect the output to an ADC. This is a very simple easy to use LPG

gas sensor, suitable for sensing Propane, Hydrogen, methane and LPG concentrations in

the air. This sensor has a very fast response time and high sensitivity.

9.2 Pins of MQ6

The connections are as follow: First connect the Vcc pin to 5V with the microcontroller,

and connect your GND to GND pin of ARM. Connect the AO pin to AO pin of ARM.

Fig 9.2 Pin diagram of MQ6

9.3 SPECIFICATIONS

1. Circuit voltage 5V ±0.1

2. Heating voltage 5V±0.1 s

3. Load resistance 20KΩ

4. Heater resistance 33Ω±5%

5. Heating consumption less than 750mw



9.4 Features

It has good sensitivity to flammable gas (especially propane) in wide range, and has

advantages such as long lifespan, low cost and simple drive circuit & etc.

Table 9.1 Features of MQ6

9.5 Main Applications

It is widely used in

domestic gas leakage alarm,

industrial flammable gas alarm and

portable gas detector.



CHAPTER 10

LIQUID CRYTAL DISPLAY(LCD)

10.1 Introduction

A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated

optical device that uses the light-modulating properties of liquid crystals. Liquid crystals

do not emit light directly, instead using a backlight or reflector to produce images in

colour or monochrome. LCDs are available to display arbitrary images (as in a general-

purpose computer display) or fixed images with low information content, which can be

displayed or hidden, such as pre-set words, digits, and 7-segment displays, as in a digital

clock. They use the same basic technology, except that arbitrary images are made up of a

large number of small pixels, while other displays have larger elements. LCDs are used in

a wide range of applications including computer monitors, televisions, instrument panels,

aircraft cockpit displays, and indoor and outdoor signage. Small LCD screens are

common in portable consumer devices such as digital cameras, watches, calculators, and

mobile telephones.

Fig 10.1 16*2 LCD Display



10.2 Pin Description

Fig 10.2 Pin Diagram of LCD 16*2 Display

The LCD can use a common peripheral interface for most of the devices like processors

and controllers etc. The LCD has the convenient operations for the controllers with less

number of GPIO pins. Such microcontrollers can be interfaced with LCD by using only 4

data pins and microcontrollers with more number of GPIO pins can use all the 8 data

lines. LCD’s driver circuit and display are integrated on the same board as a result if

consumes less space.



Table 10.1 Pin description



10.3 Lcd Command Codes

Table 10.2 LCD command codes



CHAPTER 11

GSM MODULE

11.1 Introduction to GSM Module

SIM800 is a complete Quad-band GSM/GPRS solution in a SMT type which can be

embedded in the customer applications.SIM800 support Quad-band

850/900/1800/1900MHz, it can transmit Voice, SMS and data information with low

power consumption. With tiny size of 24*24*3mm, it can fit into slim and compact

demands of customer design. Featuring Bluetooth and Embedded AT, it allows total cost

savings and fast time-to-market for customer applications.

Fig.11.1 Image of GSM module.



11.2 Block Diagram

Fig.11.2 Block diagram of GSM module.

11.3 Pin Diagram

Fig.11.3 PIN diagram of GSM.



11.2 Specifications

1. Quad-band 850/900/1800/1900MHz

2. GPRS multi-slot class 12/10

3. GPRS mobile station class B.

4. ComplianttoGSMphase2/2+

–Class4(2W@850/900MHz)

– Class 1 (1 W @ 1800/1900MHz)

5. Bluetooth: compliant with 3.0+EDR.

6. Dimensions: 24*24*3mm.

7. Weight: 3.14g.

8. . Control via AT commands (3GPP TS 27.007,27.005 and SIMCOM enhanced

AT Commands)

9. Supply voltage range 3.4 ~ 4.4V.

11.3 Basic Commands Of Gsm Module

To Check The Modem:

AT

OK

To Change Sms Sending Mode:

AT+CMGF=1

OK

To Send New Sms:

AT+CMGS=” MOBILE NO.”

<MESSAGE>

{CTRL+Z}



Preferred Sms Message Storage:

AT+CPMS=?

+CPMS: (“SM”),(“SM”),(“SM”)

OK

AT+CPMS?

+CPMS: “SM”,19,30,”SM”,19,30,”SM”,19,30

To Make A Voice Call:

ATD9876543210;

To Redial Last No:

ATDL

To Receive Incoming Call:

ATA

To Set A Particular Baudrate:

AT+IPR=? {To view the baud rate values}

AT+IPR=0 {TO set the modem to autobauding mode}



CHAPTER 12

IMPLEMENTED CODE

12.1 Algorithm

1) Step 1- START

2) Step 2 - Initialize all the sensors and 16x2 lcd.

3) Step 3 - Initialize the variables .

4) Step 4 - Set the pins used by sensors.

5) Step 5 – Set the baud rate at 9600 .

6) Step 6 – Variables : SensorPin,result,a,b,h and t are used to denote the ouput value of

LPG sensor , Smoke sensor , Pir , Ldr , humidity and temperature

respectively.

7) Step 7 – Now checking the condition if smoke sensor value is greater than 10 ppm -

a) Turn Lights off

b) Turn Fan off

c) Turn on Buzzer

d) Show on lcd “GAS LEAKAGE”.

e) Send msg ”FIRE AT HOME” two times at a difference of 15 sec.

8) Step 8 - Now checking the condition if LPG sensor value is greater than 600 –

a) Show on lcd “GAS LEAKAGE”.

b) Send msg ”GAS LEAKAGE” two times at a difference of 15 sec.

9) Step 9 – IF the value of door pir is greater than 750 –

a) Check the ldr , if the value is less than 650 turn the lights on else turn the

lights off.

b) Check the temp sensor, if the value is greater than 20°c then turn the fan

on or else turn the fan off.



Else check the window pir if greater than 750 then –

a) Turn ON buzzer

b) Send msg ”INTRUDER ALERT” two times at a difference of 15 sec.

10) Step 10 – Repeat the steps 7 to 9 continously.

11) Step 11 - STOP

12.2 Code

#include <DHT11.h> //Header file to include DHT11 functions

#include <LiquidCrystal.h> // Header file to include LCD functions

LiquidCrystal lcd(12,11,10,9,8,7); //Pins to which lcd is connected in audrino

#define sensor A0 //Smoke sensor

#define load_Res 10 // Load resistance

#define air_factor 9.83 //Air factor

#define led 6 //Pin for led

#define buzzled 5 //Pin for Buzzer

#define fanled 3 //Pin for Fan

#define doorpir A2 //Pin for Door PIR

#define winpir A4 //Pin for Window PIR

#define LDR A1 //Pin for LDR

int d,l,w; //declaring variables

int sensorPin = A3; //Pin for LPG SENSOR



int ledPin = 13; // select the pin for the LED

int sensorValue = 0;

float SmokeCurve[3] ={2.3,0.53,-0.44}; // (x, y, slope) x,y coordinate

float Res=0;

int pin=4; //Pin for Temp sensor

DHT11 dht11(pin);

void setup()

{

Serial.begin(9600); //Set baud rate

lcd.begin(16,2); //Initialize lcd

pinMode(led,OUTPUT); //Set as output pin

pinMode(buzzled,OUTPUT); //Set as output pin

pinMode(fanled,OUTPUT); //Set as output pin

while (!Serial) {

; // wait for serial port to connect. Needed for Leonardo only

}

lcd.setCursor(0,0); //Set the cursor at position(0,0)

lcd.print("GSM based Home"); //Display

lcd.setCursor(0,1); //Set the cursor at position(0,0)

lcd.print("Security System"); //Display

delay(1000);

Serial.println(" TEST!");

Serial.println("AT+CNMI=2,2,0,0,0");

Res = SensorCalibration(); //Load value of subroutine in Res

void loop() //Loop subroutine

{

sensorValue = analogRead(sensorPin); //LPG SENSOR value

Serial.print("LPG VALUE - ");

Serial.println(sensorValue); //Print lpg sensor value



delay(1000);

float res=resistance(5,50); //SMOKE SENSOR value

res/=Res;

int result=pow(10,(((log(res)-SmokeCurve[1])/SmokeCurve[2]) + SmokeCurve[0])); //convert

to ppm

Serial.print("Smoke sensor - ");

Serial.print(result); //Print Smoke sensor value

Serial.println(" PPM");

d=analogRead(doorpir); //DOOR PIR value into d

Serial.print("DOOR PIR - ");

Serial.println(d);

w=analogRead(winpir); //WINDOW PIR value into w

Serial.print("WINDOW PIR - ");

Serial.println(w);

l=analogRead(LDR); //LDR value into l

Serial.print("LDR - ");

Serial.println(l);

delay(1000);

int err; //TEMP SENSOR value

float t, h;

if((err=dht11.read(h, t))==0) { //Error conditions

Serial.print("temperature:");

Serial.print(t);

Serial.print(" humidity:");

Serial.print(h);

Serial.println();}

else {

Serial.println();

Serial.print("Error No :");

Serial.print(err);

Serial.println(); }



delay(DHT11_RETRY_DELAY); //delay for reread

lcd.setCursor(0,0);

lcd.print("Temp : ");

lcd.setCursor(7,0);

lcd.print(t);

lcd.setCursor(12,0);

lcd.print("C ");

delay(1000);

lcd.setCursor(0,1);

lcd.print("Humidity : ");


lcd.print(h);


lcd.print("%");

delay(2000);

if(result>10) { //Smoke Sensor condition

lcd.clear();

digitalWrite(led,LOW);

digitalWrite(buzzled,HIGH);

digitalWrite(fanled,LOW);

lcd.setCursor(2,0);

lcd.print("FIRE AT HOME");

delay(1000);

for(int i=2;i>0;i--){

Serial.println("Msg - Fire At Home");

delay(5000);

Serial.println("AT+CMGF=1");

delay(200);

Serial.println("AT+CMGS=\"+918073019703\"");

delay(200); // To send & display the msg

Serial.println("FIRE AT HOME"); “FIRE AT HOME” //

// To display temperature and humidity value



delay(200);

Serial.write(26);}

lcd.clear();

delay(1000);

while(1); }

if(sensorValue>600) { //LPG SENSOR condition

lcd.clear();

lcd.setCursor(2,0);

lcd.print("GAS LEAKAGE");

for(int i=2;i>0;i--){

Serial.println("Msg - GAS LEAKAGE");

delay(5000);


delay(200);


delay(200);

Serial.println("GAS LEAKAGE");

delay(200);

Serial.write(26); }

delay(1000);

if(d>650){ // Door condition

digitalWrite(buzzled,LOW);

if(l<750){ // LDR condition

for(intj=1;j>0;j--){

lcd.clear();

lcd.setCursor(0,0);

lcd.print("Lightsareon");

delay(1000);}

digitalWrite(led,HIGH);}

elsedigitalWrite(led,LOW);

if(t>20){ // Temp condition

for(inti=1;i>0;i--){

// To send & display the msg

“GAS LEAKAGE” //



lcd.clear();

lcd.setCursor(4,0);

lcd.print("FANison");}

digitalWrite(fanled,HIGH);}

else

digitalWrite(fanled,LOW);}

else{

digitalWrite(fanled,LOW);

digitalWrite(led,LOW);

if(w>650){ // Window condition

lcd.clear();


Serial.println("INTRUDERALERT");

lcd.setCursor(0,0);

lcd.print("INTRUDERALERT");


for(inti=2;i>0;i--){

Serial.println("MsgINTRUDERALERT");

delay(5000);


delay(200);


delay(200);

Serial.println("INTRUDERALERT");

delay(200);

Serial.write(26);}

delay(1000);}} }

float resistance(int samples, int interval){ // Subroutine to determine the

resistance value

int i;

float res=0;

for (i=0;i<samples;i++)

{



int adc_value=analogRead(sensor);

res+=((float)load_Res*(1023-adc_value)/adc_value);

delay(interval);

}

res/=samples;

return res;

}

float SensorCalibration(){ // Subroutine to measure

resisatance value

int i; detrmining the value of variable

val

float val=0; to perform sensor calibration

//

val = resistance(50,50);

val = val/air_factor;

return val;

}



CHAPTER 13

CONCLUSION

12.1 Result

The system is tested on the model of smart home . The system is very simple and easy to

use. The GSM based home security system has been designed and tested with the mobile

network. The user can get alerts anywhere through the GSM technology thus making the

system location independent. A flexible way to control and explore the services of the

mobile, AT commands is used in the system. The communication of home is only through

the SMS which has been tested with the mobile networks and is working on any mobile

network.

The system has tested on the model of smart home and further it will be tested in actual

home. The complexity of the algorithm of the system can be increased by introducing

number of sensors to make the energy efficient home.

The developed GSM based security system gives good response to the sensor and sends

SMS when it detects the fire or temperature is increased above desired level or detection

of intrusion at the windows. The time taken by the system to deliver the SMS is

dependent on the coverage area or range of the specified mobile network. If the mobile is

in the range of the system then the SMS is delivered in 25-30 seconds.

Advantages of the proposed system:

1. As the system is SMS based, there is no need to have extra circuitry to transmit SMS.

Mobile networks are used for transmission.

2. It is very cost effective, as day by day the cost of SMS is reducing.



Drawbacks of the proposed system:

1. All over the world, there could be a area where the mobile network is not established,

so no connectivity of mobile phones in that area. Therefore, SMS cannot be delivered.

2. Older people still are not familiar with the use of mobile and find it difficult to see the

SMS on mobile.

12.2 Future work

The developed GSM based home security systems works well with many of the

practical day to day security needs of smart home but the system can be further improved

by adding an pressure sensor to the door to detect the intruders that enter by forced entry

through the door , at present all entry through the door is considered to be an authorized

entry.

Also there can be several software patches that can be added to reduce the Time

& Complexity problem of the code. The code can also be designed in such a way that in

case of fire or intrusion, not only the owner but also the appropriate authorities can be

informed by sending them the house location, so that a better and comprehensive security

system is achieved.



REFERENCES

[1] The-History-of-Home-Security 4th July 2010 [Online]. Available:

http://ezinearticles.com.

[2] V. Karri and J. S. Daniel Lim, “Method and Device to Communicate via SMS After a

Security Intrusion”, 1st International Confe-rence on Sensing Technology, Palmerston

North, New Zealand, (2005) November 21- 23.

[3] Y. Zhao and Z. Ye, “Low cost GSM/GPRS BASED wireless home security system”,

IEEE Trans. Consumer Electron, vol. 56, no. 4, (2007) January, pp. 546-567.

[4] Z. Bing, G. Yunhung, L. Bo, Z. Guangwei and T. Tian, “Home Video Security

Surveillance”, Info-Tech and Infonet, 2001,Proceedings,ICII 2001-Beijing. 2001

International Conference, vol. 3, pp. 202-208.

[5] M. Meyer, M. Hotter and T. Ohmacht, “A new system for Video-based Detection of

moving objects and its integration into digital networks”, Security Technology 1996, 30th

Annual 1996 International Carnahan Conference, (1996), pp. 105-110.

[6] Mae , Y,; Sasao , N .; INNoue ,K. ; Arai,T.; “Person Detection by Mobile Manipulator

for Monitoring”,SICE 2003 Annual Conference, pages-2801-2806.

[7] “SMS Based Wireless Global Range Automation & Security System”, Sudipan Saha,

Sutasom Bhaumik.

[8] “Analysis and Performance of a Low Cost SMS Based Home Security System”,

Sheikh Izzal Azid, Sushil Kumar, International Journal of Smart Home, vol. 5, no. 3,

(2011) July.

[9] M. Butt, M. Khanam, A. Khan, M. Sikandar and H. Khiyal, “Controlling Home

Appliances Remotely Through Voice Command”, (IJACSA) International Journal of Ad-

vanced Computer Science and Applications, Special Issue on Wire-less & Mobile

Networks, pp. 35-39.

Smart Home Security System Based On GSM Technology ...

Documents

Transcript of Smart Home Security System Based On GSM Technology ...