full report on cell phone based door opening system using microcontroller

April 2014 Cell phone based DTMF controlled garage door opening system

CHAPTER 1

INTRODUCTION

In this age of digital technology, every device and its operation has become

digital. Now with digital based door lock systems, it is easier to control the door

movement of garage door or house. The new automated door lock system does not need a

key to lock or unlock the door.

This digital door entry system is in fact controlled by cell phone which is actually

performing the role of remote over here. The keyless door remote is an electronic circuit

based device. This remote transmits DTMF signals via air to another device of the system

installed in the garage door. This system can be operated from any corner of the world.

The working of this locking system is very simple. You just have to carry the cell phone

with yourself and you can control the locks from anywhere without any problem. It works

on the entry number. The owner has to press that entry number on the cell phone for

controlling the locking system. The entry number is unique in nature and so is the remote

device of an automatic keyless system.

You can install a keyless entry system in your house as well as in your vehicle.

Now, a day’s theft cases are increasing everywhere and the key based locking system is

no longer a safe option. It is quite easy for thieves and robber’s to open the traditional key

based doors either with duplicate keys or some other way. Therefore for safety of your

house and vehicle, this system can be installed. With this system, you will never be in

tension of leaving your house and vehicle out of your supervision. Not only this, it also

help us to move out of some really odd situations like you locked the door and left and in

your absence other members came back and then they have to wait outside if they were

not having key with themselves.

Mobile phones today became very popular an essential entity for one and all and

so, for any mobile based application there is great reception. Wireless controlled systems

utilize RF circuits which had limitations like limited range, limited frequency ranges and

controls. But a mobile phone controlled systems can hold up these limitations.

Dept. of Electronics and Communication 1 MET’S School of Engineering, Mala


1.1 MOTIVATION

Keyless entry has been a luxury whose availability is confined primarily to

vehicles. The cell phone security system takes this idea of key less entry and transforms it

in to a convenient, versatile security system that utilizes cell phone technology and the

land line telephone network. By taking the advantage of caller identification and dual-

tone multi frequency signalling, the security system has the ability to introduce two levels

of security. The first level will be decoding the calling party’s identification information

while the second level would consist of the user attempting a pass word entry over the

phone. By combining the mobility of this telecommunication medium with

microcontrollers, the system achieves a secure, convenient and automated form of

security for a place of residence.

1.2 OBJECTIVE

The main objective of this system is to unlock a door by a mobile phone using a

unique code entered through the keypad of the phone. The other objective include,

correctly decode the DTMF signals from the users mobile.

1.3 ORGANIZATION

The first chapter is introduction, and it includes motivation and objectives of our

project. Second chapter is existing systems and it describes the prototype of our system

where we got the idea from. Third chapter deals with proposed systems which includes

block diagram, circuit diagram, working and theory. Evaluation tool is the fourth chapter,

which helped us in the simulation of project.

Fifth chapter is PCB design and fabrication. It is one of the most important

chapter, which contains PCB designing, manufacturing, PCB layout, and component

layout. Next chapter is deals with project estimation which give an idea about total cost

incurred in our project. Advantages and applications are explained in chapter 7.the

following chapter deals with results and discussion about the result obtained. The final

chapter is conclusion. In this we conclude our project, and explain the modifications that

can be applied to the system in future.



CHAPTER 2

EXISTING SYSTEM

The previous lock methods have proven to be a bit unsatisfactory in one way or

the other. Though, some have advantages outweighing the disadvantages while others

have much more disadvantages. Due to the fact that live and property may be at stake, it

is important to always have a reliable lock system, putting into consideration the high rate

of crime and insecurity. Most door lock systems also require carrying external lock

devices which complete the system; this may include keys, cards, remote controls, etc. On

losing any of these devices, one may need to change the lock system in order to apply

precaution(s) in case they have fallen into wrong hands.

As interest in wireless communication continues to grow, the remote controlled

systems are increasingly being integrated into everyday life. Even though modern

technology has allowed for the automation of many aspects of domestic lifestyles, from

automatic motion sensing lights, automatic control of home appliances to automatic

garage door openers, all these system use RF technology for wireless control. . However,

the use of RF contributes to enhancing the already mysterious nature of communication

strategies, which had limitations like limited range.

Also, due to the rapid growth in computer, GSM control system and technology

advancement in general, it may be seen worthwhile to move with the recent trends either

privately-in our homes or in our establishments.



CHAPTER 3

PROPOSED SYSTEM

The main objective of this system is to unlock a door by a mobile phone using a

unique code entered through the keypad of the phone. Opening and closing of doors

involves human to be physically involved in to the task. In this cell phone controlled,

password protected door locking system, the opening and closing of a door is achieved by

using a mobile phone.

This article summarizes the use of DTMF signalling technology to send and

receive the control commands from user in order to open or close the door. Password

protection is given to the system with help of microcontroller and corresponding

algorithm that authenticate the user by checking the password provided by the user. So, if

and only if the user press correct password then only user get authenticate and gets the

access to open or close the door.

3.1BLOCK DIAGRAM


Fig.3.1 Block Diagram


Power Supply

The power supply provides the necessary voltage to the entire circuit. The power

supply section consists of mainly a step down transformer, a bridge rectifier and a fixed

voltage regulator. A step down transformer and a bridge rectifier is used to convert the

230V/50Hz AC to DC. Two regulators IC’s 7805 and 7806 are also used here to give

constant supply of 5V and 6V to all sub systems.

DTMF Decoder

DTMF decoder, decode the DTMF (Dual tone multi frequency) signals from

mobile phone into the equivalent binary form. For example, if ’2’ is pressed on the

keypad, the output of the decoder will be 0010. Here we use DTMF receiver IC, Motorola

MT8870, which is an 18-pin IC.

Microcontroller

It is the heart of our system. Microcontroller is pre programmed to take decision

corresponds to input. Password protection is given to the system with the help of a

microcontroller and corresponding algorithm that authenticate the user by checking the

password provided by the user. The microcontroller here we used is Atmega 8. It is a 28

pin DIP High-performance, Low-power Atmel®AVR® 8-bit Microcontroller and has

8Kbytes of In-System Self-programmable Flash program memory.

Motor and Driver Circuit

This section consist of a DC motor, relay, NPN transistor BC 548 and a resistor of

10k. The motor used over here is a 5V DC motor. Motor drivers acts as current amplifiers

since they take a low control signal and provide a high current signal. This higher current

is used to drive the motor. Relay is an electrically operated switch used to cut off the

load. The relay used here is SPDT switch that is single pole double throw. Here a

common terminal connects to either of two others.

LCD Module

A 16x2 LCD module is used here to display instructions to the user. It consists of

16 rows and 2 columns of 5x7 or 5x8 LCD dot matrices. It is available in a 16pin package



with back light, contrast adjustment function and each dot matrix has 5x7 or 5x8 dot

resolution.

Matrix Keypad

A 4x4 matrix key pad is used as a substitute for entering the password in case, the

user forgot to take his mobile phone in his hand.

3.2 CIRCUIT DIAGRAM

Fig.3.2 Circuit Diagram

3.3 WORKING AND THEORY

This project use of DTMF signalling technology to send and receive the control

commands from user in order to open or close the door. Password protection is given to

the system with help of microcontroller and corresponding algorithm that authenticate the

user by checking the password provided by the user. So, if and only if the user press

correct password then only user get authenticate and gets the access to open or close the

Door. The user in order to open the door should make a voice call to the phone which is

stacked with the controller unit acting as receiver mobile. This receiver mobile is kept in

auto answer mode. So after a ring it will automatically accept the call. Now if user presses



any button on keypad of phone, the tone corresponds to that button is sent to other end.

This tone is fed to DTMF Decoder, where the DTMF frequency is converted in to the

equivalent digital form. For example, if 2 is pressed on the keypad, the output of the

decoder will be 0010. This digital information is given to the microcontroller. The

Microcontroller is pre-programmed to take decision corresponds to input button pressed.

A 16x2 LCD display is interfaced with the control unit to display instructions to user.

Depending upon the user password, controller will decide to open/close the door if the

user get authenticate, by using relay drive circuit and motor.

Fig. 3.2 illustrates the actual circuit that has been used to obtain the working

model of cell phone controlled, password protected door locking system. It consists of

Microcontroller, motor driver circuit, DTMF Decoder, LCD display,4x4 matrix keypad

and a power supply section. The microcontroller here we used is Atmega 8.Initially

microcontroller accepts binary input from DTMF decoder MT8870 to OPEN/CLOSE the

door respectively. Digital information coming from DTMF decoder is fed to the

microcontroller. The input from the receiver mobile is given to the pin no. 2 of DTMF

decoder ( MT8870) Via a resistor capacitor circuitry through a audio jack pin of receiver

mobile.

DTMF

When you press a button in the telephone keypad, a connection is made that

generates a resultant signal of two tones at the same time. These two tones are taken from

a row frequency and a column frequency. The resultant frequency signal is called "Dual

Tone Multiple Frequency". These tones are identical and unique. A DTMF signal is the

algebraic sum of two different audio frequencies, and can be expressed as follows:

f(t) = A0sin(2*П*fa*t) + B0sin(2*П*fb*t) + ...........(1)

Where fa and fb are two different audio frequencies with A and B. DTMF signal

fa belongs to the low frequency group and fb belongs to the high frequency group. Each

of the low and high frequency groups comprise four frequencies from the various keys

present on the telephone keypad; two different frequencies, one from the high frequency

group and another from the low frequency group are used to produce a DTMF signal to

represent the pressed key. The amplitudes of the two sine waves should be such that

(0.7 < (A/B) < 0.9)V ……….(2)



The frequencies are chosen such that they are not the harmonics of each other. The

frequencies associated with various keys on the keypad are shown in table.

Table 3. 1 Telephone Keypad with Frequency

1209 Hz 1336 Hz 1477 Hz 1633 Hz

697 Hz 1 2 3 A

770 Hz 4 5 6 B

852 Hz 7 8 9 C

941 Hz * 0 # D

When you send these DTMF signals to the telephone exchange through cables, the

servers in the telephone exchange identifies these signals and makes the connection to the

person you are calling. When you press the digit 5 in the keypad it generates a resultant

tone signal which is made up of frequencies 770Hz and 1336Hz. Pressing digit 8 will

produce the tone taken from tones 852Hz and 1336Hz. In both the cases, the column

frequency 1336 Hz is the same. These signals are digital signals which are symmetrical

with the sinusoidal wave. Due to its accuracy and uniqueness, these DTMF signals are

used in controlling systems using telephones. By using some DTMF generating IC‟s

(UM91214, UM91214, etc.) we can generate DTMF tones without depending on the

telephone set.

IC MT 8870

The MT-8870 is a full DTMF Receiver that integrates both band split filter and

decoder functions into a single 18-pin DIP. Its filter section uses switched capacitor

technology for both the high and low group filters and for dial tone rejection. Its decoder

uses digital counting techniques to detect and decode all 16 DTMF tone pairs into a 4-bit

code. Provision of an on-chip differential input amplifier, clock generator, and latched tri-



state interface bus. Minimal external components required include a low-cost 3.579545

MHz crystal, a timing resistor, and a timing capacitor. MT-8870 operating functions

include a band split filter that separates the high and low tones of the received pair, and a

digital decoder that verifies both the frequency and duration of the received tones before

passing the resulting 4-bit code to the output bus. The low and high group tones are

separated by applying the dual-tone signal to the inputs of two 6th order switched

capacitor band pass filters with bandwidths that correspond to the bands enclosing the

low and high group tones.

Fig. 3.3 IC 8870 Block Diagram

The filter also incorporates notches at 350 and 440 Hz, providing excellent dial

tone rejection. Each filter output is followed by a single-order switched capacitor section-



that smoothest the signals prior to limiting. Signal limiting is performed by high gain

comparators provided with hysteresis to prevent detection of unwanted low-level signals

and noise.

The MT-8870 decoder uses a digital counting technique to determine the

frequencies of the limited tones and to verify that they correspond to standard DTMF

frequencies. When the detector recognizes the simultaneous presence of two valid tones

(known as signal condition), it raises the Early Steering flag (EST). Any subsequent loss

of signal condition will cause EST to fall. Before a decoded tone pair is registered, the

receiver checks for valid signal duration (referred to as character- recognition-condition).

This check is performed by an external RC time constant driven by Est. A short delay to

allow the output latch to settle, the delayed steering output flag (STD) goes high,

signalling that a received tone pair has been registered. The contents of the output latch

are made available on the 4-bit output bus by raising the three state control input (OE) to

logic high. Inhibit mode is enabled by a logic high input to pin 5 (INH). It inhibits the

detection of 1633 Hz. The output code 13 will remain the same as the previous detected

code. On the M- 8870 models, this pin is tied to ground (logic low).

The input arrangement of the MT-8870 provides a differential input operational

amplifier as well as a bias source (VREF) to bias the inputs at mid-rail. Provision is made

for connection of a feedback resistor to the op-amp output (GS) for gain adjustment.

The internal clock circuit is completed with the addition of a standard 3.579545 MHz

crystal.

ATMEGA8L – MICROCONTROLLER

It is a High-performance, Low-power Atmel AVR 8-bit Microcontroller. AVR is

a modified Harvard architecture 8-bit RISC single chip microcontroller which was

developed by Atmel in 1996. The AVR was one of the first microcontroller families to

use on-chip flash memory for program storage, as opposed to one-time programmable

ROM, EPROM, or EEPROM used by other microcontrollers at the time. Flash EEPROM,

and SRAM are all integrated onto a single chip, removing the need for external memory

in most applications.


http://en.wikipedia.org/wiki/Static_random-access_memory

http://en.wikipedia.org/wiki/EEPROM

http://en.wikipedia.org/wiki/Flash_memory

http://en.wikipedia.org/wiki/EEPROM

http://en.wikipedia.org/wiki/EPROM

http://en.wikipedia.org/wiki/Programmable_read-only_memory

http://en.wikipedia.org/wiki/Programmable_read-only_memory

http://en.wikipedia.org/wiki/Flash_memory

http://en.wikipedia.org/wiki/Atmel

http://en.wikipedia.org/wiki/Microcontroller

http://en.wikipedia.org/wiki/Reduced_instruction_set_computer

http://en.wikipedia.org/wiki/8-bit

http://en.wikipedia.org/wiki/Modified_Harvard_architecture


Some devices have a parallel external bus option to allow adding additional data

memory or memory-mapped devices. Almost all devices (except the smallest Tiny AVR

chips) have serial interfaces, which can be used to connect larger serial EEPROMs or

flash chips.

FEATURES

• High-performance, Low-power Atmel® AVR® 8-bit Microcontroller

• Advanced RISC Architecture

130 Powerful Instructions – Most Single-clock Cycle Execution

32 × 8 General Purpose Working Registers

Fully Static Operation

Up to 16MIPS Throughput at 16MHz

On-chip 2-cycle Multiplier

• High Endurance Non-volatile Memory segments

8Kbytes of In-System Self-programmable Flash program memory

512Bytes EEPROM

1Kbyte Internal SRAM

• Peripheral Features

Two 8-bit Timer/Counters with Separate Prescaler, one Compare Mode

One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture

Mode

Real Time Counter with Separate Oscillator

Three PWM Channels

8-channel ADC in TQFP and QFN/MLF package

Byte-oriented Two-wire Serial Interface

Programmable Serial USART

Master/Slave SPI Serial Interface



Programmable Watchdog Timer with Separate On-chip Oscillator

On-chip Analog Comparator

ATmega 8 can be mapped with Arduino Development Software. The pin mapping for the

ATmega is given below.

ATMEGA 8L

Fig.3.4 Pin Details of Atmega8L



CHAPTER 4

EVALUATION TOOLS

4.1 PROTEUS

Proteus 8 is a single application with many service modules offering different

functionality (schematic capture, PCB layout, etc.). The wrapper that enables all of the

various tools to communicate with each other consists of three main parts.

Application Framework

Proteus 8 consists of a single application (PDS.EXE). This is the framework or

container which hosts all of the functionality of Proteus. ISIS, ARES, 3DV all open as

tabbed windows within this framework and therefore all have access to the common

database.

Common Database

The common database contains information about parts used in the project. A part

can contain both a schematic component and a PCB footprint as well both user and

system properties. Shared access to this database by all application modules makes

possible a huge number of new features, many of which will evolve over the course of the

Version 8 lifecycle.

Live Netlist

Together with the common database the maintenance of a live netlist allows all

open modules to automatically reflect changes. The most obvious example of this is

wiring in ISIS producing ratsnest connections in ARES but it goes much further than that.

The new Bill of Materials module contains a live viewer and the 3D Viewer and Design

Explorer are also linked into the live netlist. The strength of its architecture has allowed

us to integrate first conventional graph based simulation and with Proteus VSM

interactive circuit simulation into the design environment.



You can now draw a complete-circuit for a micro-controller based system and

then test it interactively, all from within the same piece of software. Meanwhile, ISIS

retains a host of features aimed at the PCB designer, so that the same design can be

exported for production with ARES or other PCB layout software

Features

Runs on Windows XP onwards.

Automatic wire routing and dot placement/removal.

Powerful tools for selecting objects and assigning their properties.

Total support for buses including component pins, inter-sheet terminals, module

ports and wires.

Live netlisting to the ARES Layout module and additional netlist outputs to suit

other PCB layout tools.

Design Global Annotation allowing multiple instances of a sub-circuit to have

different component references.

Automatic Annotation - the ability to number the components automatically.

ISIS & ARES

Users intending to design PCB's using the ARES Layout module will find some of

the following PCB layout specific features of interest:

The ability to assign and configure net classes directly from the place wire label

command on a schematic connection. This allow you to specify trace width and

via styles and feeds into the design rule manager in ARES where you can further

configure board constraints.

Sheet Global Net Properties which allow you to efficiently define a net class for

all the nets on a given sheet (e.g. a power supply needing POWER width tracks).

Physical terminals which provide the means to have the pins on a connector

scattered all over a design.

A visual packaging tool which shows the PCB footprint and its pin numbers

alongside the list of pin names for the schematic part ISIS & Simulation.



ISIS & SIMULATION

ISIS provides the development environment for PROTEUS VSM. This product

combines mixed mode circuit simulation, micro-processor models and interactive

component models to allow the simulation of complete micro-controller based designs.

ISIS provides the means to enter the design in the first place, the architecture for

real time interactive simulation and a system for managing the source and object code

associated with each project. In addition, a number of graph objects can be placed on the

schematic to enable conventional time, frequency and swept variable simulation to be

performed.

4.2 ARDUINO UNO

Arduino is an open-source electronics prototyping platform based on flexible,

easy-to-use hardware and software. It's intended for artists, designers, hobbyists and

anyone interested in creating interactive objects or environments. Arduino can sense the

environment by receiving input from a variety of sensors and can affect its surroundings

by controlling lights, motors, and other actuators. The microcontroller on the board is

programmed using the Arduino programming language(based on Wiring) and the

Arduino development environment(based on Processing).

Arduino projects can be stand-alone or they can communicate with software

running on a computer (e.g. Flash, Processing, MaxMSP).The boards can be built by

hand or purchased preassembled; the software can be downloaded for free rather than

requiring a physical press of the reset button before an upload, the Arduino Uno is

designed in a way that allows it to be reset by software running on a connected computer.

One of the hardware flow control lines (DTR) of the ATmega8U2/16U2 is connected to

the reset line of the ATmega328 via a 100 nano farad capacitor. When this line is

asserted(taken low), the reset line drops long enough to reset the chip. The Arduino

software uses this capability to allow you to upload code by simply pressing the upload

button in the Arduino environment. This means that the boot loader can have a shorter

time out, as the lowering of DTR can be well-coordinated with the start of the upload.


http://arduino.cc/en/Main/Software

http://arduino.cc/en/Main/Buy

http://arduino.cc/en/Main/ArduinoBoardSerialSingleSided3

http://arduino.cc/en/Main/ArduinoBoardSerialSingleSided3

http://www.processing.org/

http://wiring.org.co/

http://arduino.cc/en/Reference/HomePage


CHAPTER 5

PCB DESIGNING AND FABRICATION

5.1 PCB DESIGNING

A printed circuit board, or PCB, is used to mechanically support and electrically

connect electronic components using conductive pathways, tracks or signal traces etched

from copper sheets laminated onto a non-conductive substrate. When the board has only

copper tracks and features, and no circuit elements such as capacitors, resistors or active

devices have been manufactured into the actual substrate of the board, it is more correctly

referred to as printed wiring board (PWB) or etched wiring board. Use of the term PWB

or printed wiring board although more accurate and distinct from what would be known

as a true printed circuit board, has generally fallen by the wayside for many people as the

distinction between circuit and wiring has become blurred. Today printed wiring (circuit)

boards are used in virtually all but the simplest commercially produced electronic

devices, and allow fully automated assembly processes that were not possible or practical

in earlier era tag type circuit assembly processes.

A PCB populated with electronic components is called a printed circuit assembly

(PCA), printed circuit board assembly or PCB Assembly (PCBA). In informal use the

term "PCB" is used both for bare and assembled boards, the context clarifying the

meaning. The various tools for implementing and designing the PCB is given below:

ELECTRONIC DESIGN AUTOMATION (EDA) TOOLS

With the advent of powerful computing system and interactive software, several

stages in the design and development of an electronic circuit has undergone automation.

These software and hardware tools, which enable automation, are called EDA tools. This

tools helps us in such a way that we can draw the circuit; list the functioning of the circuit

in the best inputs in assimilation software .After successful simulation of the circuit, the



placing and routing software does the PCB artwork. In this project the design automation

tool used is Dip Trace. Dip Trace is a complete PCB Design system. It includes four

programs:

PCB Layout - PCB design with easy to use manual routing tools and auto router.

Schematic - creates schematic and exports netlist to PCB.

Pattern Editor - allows to make package footprints (patterns).

Component Editor - allows to draw parts and attach patterns to them.

For creating the PCB artwork the design process is of the following steps:

Drawing the circuit schematic

This is done in Dip Trace schematic capture. It includes many libraries with

thousands of component symbols .We can select the required symbol from the library and

place it on the schematic page. After placing the component symbol, the interconnection

is completed using bus tool .After drawing the schematic, the following operations are

performed.

Convert schematic into PCB

Then select the menu option 'Switch to Board' to convert the schematic to PCB.

Layout can be updated from Schematic in a few clicks at anytime

Routing

Routing is the interconnection of components using upper tracks of required

width. Before starting routing the following things are done:

Enabling /disabling required layers:

The number of layers used and enabling the artwork depends upon the complexity of the

circuit and fabrication technology available. If the board is single sided enable only

bottom or solder side layer, so that the track will come only on one side of the PCB. If the



circuit is more complex enable the required number of inner layer considering the

fabrication technique and cost.

Manual routing / Auto routing

Dip Trace PCB software includes 2 automatic routers which is able to route complex

multi-layer boards as well as simple single-layer layouts. Intelligent manual routing tools

allow you to create and edit traces by 90, 45 degree or without any limitations. Through,

blind or buried vias can be used in automatic and manual routingIn this, the PCB design

has to manually connect each track. This is time consuming, but is required in some

cases. In this also the software checks for errors and reports.

5.2 MANUFACTURING

PROCESSING THE FILM:

The layout is printed in a’ butter paper’ using a laser printer. The layout is

transferred to the copper clad sheet using the screen print procedure. First a

negative screen of layout is prepared with the help of a professional screen printer.

Then the copper clad sheet is kept under this screen. The printed board is kept

under shade for a few hours till the ink becomes dry.

The etching medium is prepared with an-hydrous ferric chloride and water. The

printed circuit board is kept in this solution till the exposed copper dissolves in the

solution fully. After that the board is taken out and rinsed in flowing water under a

tap. The ink is removed with the help of NC thinner (available in the paint shops).

The board is coated with solder in order to prevent oxidation. Another screen,

which contains component side layout, is prepared and the same is printed on the

component side of the board. A paper epoxy laminate is used as the board.

STANDARD REQUIREMENTS:



The minimum conductor width of the finished PCB shall not be less than 0.05mm

for signal and 0.4mm for power line. The standard ratio is taken as 1:1, 5:2 for signal

power respectively.

CLEANING:

Surface of copper clad may contain oxides, greases, oil or solid. They should be

removed by the following procedure:

Wipe with cotton wool soaked with tricolour ethylene.

Dip in 10% HCL solution at room temperature.

Scrap with powder.

Rinse with chlorine free water.

Observe the wetting of water on the surface. If the wetting is uniform without any

island, the surface is clean.

ARTWORK TRANSFER:

Artwork transfer can be done in many ways and procedure used in the work is named

fabrication process. Usually used methods are:

Silk screen printing.

Photographic method.

Direct method.

In direct method artwork is transferred to clad sheet in the ratio 1:1 using paint or

permanent ink.

ETCHING:



The vast majority of printed circuit boards are made by bonding a layer of copper

over the entire substrate ,sometimes on both sides,(creating a ”blank PCB”) then

removing unwanted copper traces. A few PCBs are made by adding traces to the bare

substrate (or a substrate with a very thin layer of copper) usually by a complex process of

multiple electroplating steps.

DRILLING:

The holes for mounting components are drilled using a high speed drilling

machine. The size of the holes to be drilled will be specified during the layout designing

depending upon the component lead diameter. For drilling we use 1mm drill bit.

VARNISH COATING:

If the board is unprotected, copper oxides are formed over the conductor and it

affects sold arability and neatness of the board. For this, insulation coating such as

varnish can be used.

SOLDERING:

After the above process the components are soldered on the board. Soldering

angles varies from 5 to 29 degrees.



5.3 PCB LAYOUT

Fig.5.1 PCB layout



5.4 COMPONENT LAYOUT

Fig.5.2 Component layout



CHAPTER 6

PROJECT ESTIMATION

Table 6.1 Project Estimation


COMPONENT UNIT PRICE

NO. OF PIECES

COST

Resistors .50 10 5.00

Potentiometer 1 1 1.00

Capacitors 1.50 2 03.00

Diodes 1 4 04.00

LED 2 1 02.00

Transformer 90 1 90.00

Transistor 2 2 04.00

Relay 20 2 40.00

Atmega 8 110 1 110.00

Mt8870 35 1 35.00

Crystal Oscillator 8 2 16.00

DC Motor 150 1 150.00

LCD Module 130 1 130.00

Matrix Keypad 144 1 144.00

PCB 30 1 30.00

Total Rs:764.00


CHAPTER 7

ADVANTAGES AND APPLICATIONS

7.1 ADVANTAGES

It provides keyless entry to the premises and is a versatile security system that

utilizes cell phone technology. Overcoming the limited range of infrared and radio

remote controls. This system takes advantage of the widespread acceptance of cell phones

in automation. Our system doesn’t have the problems of range limits and we can access

the door from anywhere in the world.

7.2 APPLICATIONS

Just by pressing the key pad of mobile phone we can open or close the garage

doors automatically with a unique pass word from anywhere in the world. It include areas

like home security providing this keyless entry to door.



CHAPTER 8

RESULTS AND DISCUSSION

8.1 RESULTS

We were able to construct a ‘Cell phone based DTMF controlled garage

door opening system that could demonstrate our aim. Whenever the user entered his pass

word using mobile phone, unique frequencies are generated corresponding to the pass

word which are decoded by DTMF decoder IC at the receiving end. If this decoded

values matches with the password stored in the microcontroller, then controller initiates a

mechanism to open or close the door. Also the user could see the information and result

through the LCD module.

Fig.8.1 DTMF Signal for Digit 1

Fig.8.2 Breadboard Implementation



8.2 DISCUSSION

The DTMF signals generated were clean and virtually free of noise. We verified

this using an oscilloscope to capture the signal generated and checking for noise spikes.

Also, the DTMF decoder circuit verified that the signals were genuine DTMF signals

since they were able to be decoded. The figure above shows the DTMF signal

corresponds to digit 1. Since this signal is a mixture of 697 Hz & 1209 Hz, we added

these two frequencies and verified the obtained signal. A problem incurred with this

system is some mobile phones which working as receiver didn’t correctly decode all

DTMF signals. The filters in their audio section filter out some of the DTMF frequencies.

But mobile phones having Android application work very well with our system.



CHAPTER 9

CONCLUSION

The design and implementation of microcontroller based security door system

using mobile phone has been proven to be a reasonable advancement in door security

system technology and access control. From this experimentation we conclude that it is

feasible to implement the Cell Phone Controlled, Password Protected Door Locking

System which is in turn illustrate the use of DTMF technology for control of remote

applications.

The security system will hopefully fulfil its other primary goal which is to

influence a change within the market - a change towards a more convenient, responsive,

automated security system such as the cell phone security system. It is possible to provide

high security protection to home, banks and the places where the confidentiality, privacy

and security is to be preserved.



REFERENCES

[1] Ashish Jadhav, Mahesh Kumbhar and Meenakshi Pawar, „Cell phone Controlled

ground Combat Vehicle‟, International Journal of Computer and communication

engineering Vol. 1, No. 2, ISSN: 2010-3743, pp 114-116, July 2012.

[2] International Journal Of Electronics And Communication Engineering &

Technology (IJECET), ISSN 0976 – 6464(Print), ISSN 0976 – 6472(Online) Volume

3, Issue 2, pp pp 263-270, July-September 2012.

[3] DTMF Explained, www.genave.com/dtmf [2008, March 31].

[4] Free datasheet download site, www.alldatasheet.com [2008, June 29].

[5] Vladimir, G. (2005), "Electrical Relays: Principles and Applications", CRC Press

(Taylor & Francis group), London. Available: http://en.wikipedia.org/wiki/relays

[2008, April 10].

[6] www.arduinouno.com

[7] www.engineersgarage.com

[8] www.edgefxkits.com



APPENDIX


full report on cell phone based door opening system using microcontroller

Documents

digital door entry system

keyless entry system

cell phone security

system chapter

key based locking system

versatile security system

automatic keyless system

new automated door lock