gsm based home automation working file finished

7/27/2019 Gsm Based Home Automation Working File Finished

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GSM BASED HOME AUTOMATION

ABSTRACT

Now a day's every system is automated in order to face newchallenges in the present day situation. Automated systems have less manual

operations, so that the flexibility, reliabilities are high and accurate. Hence every

field prefers automated control systems. Especially in the field of electronics

automated systems are doing better performance.

Probably the most useful thing to know about the global system for

mobile communication is that it is an international standard. If you travel in parts

of world, GSM is only type of cellular service available. Instead of analog services,

GSM was developed as a digital system using TDMA technology.

The goal of the project is to develop a system, which uses Mobile

technology that keeps control of the various units of the automobiles, which

executes with respect to the signal sent by the mobile.

For utilization of appliances the new concept has been thought

to manage them remotely by using GSM, which enables the user to remotely

control switching of domestic appliances. Just by dialing keypad of remotetelephone, from where you are calling you can perform ON / OFF operation of the

appliances. The ranges of appliances that can be controlled through tele remote

systems are many in numbers. Some of them are as follows and this depends upon

the usage priority of the appliances i.e. Industrial appliances, Music System or

other electrical / electronic appliances.

The project contains GSM module contains SIM which receives

the SMS from the user mobile, contains the password in the SMS and it read by thePIC18F452 micro controller then compares with the code password in

microcontroller, if password matches the controller switch on or off the appliances

connected to the project. The uniqueness of this project is we can have access the

appliances all over the world connected to this project


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BLOCK DIAGRAM OF GSM BASED HOME AUTOMATION

Introduction:

This project deals with the implementation of GSM technology on a pic

microcontroller so that the home application can be enabled. The following is the

block diagram for gsm enabled embedded systems for controlling homeappliances.

TX

RX

PIC18F452Micro

controller

unitGSMMODU

LE

Power

supply DC

12V

MOBILE

(GSM)

LEDS

L293D IC DCMOTO

R

SMS RECEIVING ANDSENDING


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GSMMODULE

System operation flow diagram

MAIN BOARD

MICROCONTROLLER

GSM MODULESIM

SLOT

TX

LEDS SLOT

DCMOTOR

I

C

RX

12VOLT

DC


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GSM Technology Guide

Time-Division Multiple Access (TDMA)

What is TDMA?

TDMA (time division multiple access) is a technology used in digital

cellular telephone communication to divide each cellular channel into three time

slots in order to increase the amount of data that can be carried.

How it Works?

TDMA works by time-division multiplexing: sending multiple signals (each

of which has its own time slot) simultaneously on a single carrier in the form of a

complex signal, and then recovering the separate signals at the receiving end. For

TDMA, the carrier is divided into three time slots, each of which serves one

subscriber. The information is broken into tiny data packets, which are transmitted

in timed bursts in the 30-megahertz range. At the receiving end, the separate

information streams are recovered. See also FDMA (frequency division multiple

access) and CDMA (code-division multiple access).

TDMA was developed in response to the basic wireless network problem:

Code Division Multiple Access (CDMA):

The term CDMA refers to any of several protocols used in so-called second-

generation (2G) and third-generation (3G) wireless communications. As the term

implies, CDMA is a form of multiplexing, which allows numerous signals to

occupy a single transmission channel, optimizing the use of available bandwidth.

The technology is used in ultra-high-frequency (UHF) cellular telephone systems

in the 800-MHz and 1.9-GHz bands. CDMA employs analog-to-digital conversion

(ADC) in combination with spread spectrum technology.

Global System for Mobile communication (GSM):

What is GSM?

The Global System for Mobile communication, usually called GSM,

Telecommunications Standards Institute (ETSI) to describe protocols for second

generation (2G) digital cellular networks used by mobile phones. The GSM

standard was developed as a replacement for first generation (1G) analog cellular
http://en.wikipedia.org/wiki/European_Telecommunications_Standards_Institutehttp://en.wikipedia.org/wiki/2Ghttp://en.wikipedia.org/wiki/Cellular_networkhttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/1Ghttp://en.wikipedia.org/wiki/European_Telecommunications_Standards_Institutehttp://en.wikipedia.org/wiki/2Ghttp://en.wikipedia.org/wiki/Cellular_networkhttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/1G


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networks, and originally described a digital, circuit switched network optimized

forfull duplex voice telephony. This was expanded over time to include data

communications, first by circuit switched transport, then packet data transport

via GPRS (General Packet Radio Services) and EDGE (Enhanced Data rates for

GSM Evolution or EGPRS). Further improvements were made whenthe 3GPP developed third generation (3G) UMTS standards followed by fourth

generation (4G)LTE Advanced standards. "GSM" is a trademarkowned by

the GSM Association.

The Generations of Mobile Networks

The idea of cell-based mobile radio systems appeared at Bell Laboratories in

the United States in the early 1970s. However, mobile cellular systems were not

introduced for commercial use until a decade later. During the early 1980s, analog

cellular telephone systems experienced very rapid growth in Europe, particularly in

Scandinavia and the United Kingdom. Today, cellular systems still represent one

of the fastest growing telecommunications systems. During development,

numerous problems arose as each country developed its own system, producing

equipment limited to operate only within the boundaries of respective countries,

thus limiting the markets in which services could be sold.

First-generation cellular networks, the primary focus of the communications

industry in the early 1980s, were characterized by a few compatible systems that

were designed to provide purely local cellular solutions. It became increasinglyapparent that there would be an escalating demand for a technology that could

facilitate flexible and reliable mobile communications. By the early 1990s, the

lack of capacity of these existing networks emerged as a core challenge to keeping

up with market demand.

History of GSM:

Early European analog cellular networks consisted of a mix of technologiesand protocols that varied from country to country, meaning thatphones did not

necessarily work on different networks. In addition, manufacturers had to produce

different equipment to meet various standards across the markets.

In 1982, work began to develop a European standard for digital cellular

voice telephony when the European Conference of Postal and Telecommunications
http://en.wikipedia.org/wiki/Duplex_(telecommunications)#Full_duplexhttp://en.wikipedia.org/wiki/Telephonyhttp://en.wikipedia.org/wiki/GPRShttp://en.wikipedia.org/wiki/EDGEhttp://en.wikipedia.org/wiki/3GPPhttp://en.wikipedia.org/wiki/3Ghttp://en.wikipedia.org/wiki/UMTShttp://en.wikipedia.org/wiki/4Ghttp://en.wikipedia.org/wiki/LTE_Advancedhttp://en.wikipedia.org/wiki/Trademarkhttp://en.wikipedia.org/wiki/GSM_Associationhttp://en.wikipedia.org/wiki/1Ghttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/European_Conference_of_Postal_and_Telecommunications_Administrationshttp://en.wikipedia.org/wiki/Duplex_(telecommunications)#Full_duplexhttp://en.wikipedia.org/wiki/Telephonyhttp://en.wikipedia.org/wiki/GPRShttp://en.wikipedia.org/wiki/EDGEhttp://en.wikipedia.org/wiki/3GPPhttp://en.wikipedia.org/wiki/3Ghttp://en.wikipedia.org/wiki/UMTShttp://en.wikipedia.org/wiki/4Ghttp://en.wikipedia.org/wiki/LTE_Advancedhttp://en.wikipedia.org/wiki/Trademarkhttp://en.wikipedia.org/wiki/GSM_Associationhttp://en.wikipedia.org/wiki/1Ghttp://en.wikipedia.org/wiki/Mobile_phonehttp://en.wikipedia.org/wiki/European_Conference_of_Postal_and_Telecommunications_Administrations


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Mobile Station

The mobile station (MS) consists of the mobile equipment (the

terminal) and a smart card called the Subscriber Identity Module (SIM). The

SIM provides personal mobility, so that the user can have access to

subscribed services irrespective of a specific terminal. By inserting the SIMcard into another GSM terminal, the user is able to receive calls at that

terminal, make calls from that terminal, and receive other subscribed services.

The mobile equipment is uniquely identified by the International

Mobile Equipment Identity (IMEI). The SIM card contains the International

Mobile Subscriber Identity (IMSI) used to identify the subscriber to the

system, a secret key for authentication, and other information. The IMEI and

the IMSI are independent, thereby allowing personal mobility. The SIM card

may be protected against unauthorized use by a password or personal identity

number.

Base Station Subsystem

The Base Station Subsystem is composed of two parts, the Base

Transceiver Station (BTS) and the Base Station Controller (BSC). These

communicate across the standardized Abis interface, allowing (as in the rest

of the system) operation between components made by different suppliers.

Network Subsystem

The central component of the Network Subsystem is the Mobile

services Switching Center (MSC). It acts like a normal switching node of the

PSTN or ISDN, and additionally provides all the functionality needed to

handle a mobile subscriber, such as registration, authentication, location

updating, handovers, and call routing to a roaming subscriber. The MSC

provides the connection to the fixed networks (such as the PSTN or ISDN).

Signaling between functional entities in the Network Subsystem uses

Signaling System Number 7 (SS7), used for trunk signaling in ISDN and

widely used in current public networks.


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GSM SECURITY:

The security features in the GSM network can be divided into three sub

parts: subscriber identity authentication, user and signaling data confidentiality,

and subscriber identity confidentiality. The security mechanisms include secret

keys, algorithms and computed numbers.Some definitions:

Authentication any technique that enables the receiver to automatically

identify and reject messages that have been altered deliberately or by

channel errors

Confidentiality only the sender and intended receiver should be able to

understand the contents of the transmitted message

Cipher text plaintext is encrypted to cipher text with the help of a key and

an encryption algorithm Key a string of numbers or characters as input to the encryption algorithm

.

Subscriber Identity Authentication. The procedure consists of three phases, (1) the

network must identify the subscriber, (2) needed security parameters from the

home network are asked for and (3) the actual authentication is taking place.

A 3-digit Mobile Country Code (MCC). This identifies the country where

the GSM system operates. Finland has number 244.

A 2-digit Mobile Network Code (MNC). This uniquely identifies eachcellular provider. Sonera has number 91.

The Mobile Subscriber Identification Code (MSIC).This uniquely identifies

each customer of the provider. The length is 10 digits


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Channel structure:

Depending on the kind of information transmitted (user data and control

signaling), we refer to different logical channels which are mapped under physical

channels (slots). Digital speech is sent on a logical channel named TCH, which

during the transmission can be a allocated to a certain physical channel. In a GSMsystem no RF channel and no slot is dedicated to a priori to the exclusive use of

anything (any RF channel can be used for number of different uses).

Logical channels are divided into two categories:

i) Traffic Channels (TCHs)

ii)Control Channels .

Traffic Channels (TCHs)

A traffic channel (TCH) is used to carry speech and data traffic. Trafficchannels are defined using a 26-frame multiform, or group of 26 TDMA frames.

The length of a 26-frame multiform is 120 ms, which is how the length of a burst

period is defined (120 ms divided by 26 frames divided by 8 burst periods per

frame). Out of the 26 frames, 24 are used for traffic, 1 is used for the Slow

Associated Control Channel (SACCH) and 1 is currently unused. TCHs for the

uplink and downlink are separated in time by 3 burst periods, so that the mobile

station does not have to transmit and receive simultaneously, thus simplifying the

electronics

TCHs carry either encoded speech or user data in both up and down

directions in a point to point communication.

There are two types of TCHs that are differentiated by their traffic rates.

They are: i. Full Rate TCH

ii. Half Rate TCH

Full Rate TCH(Also represented as Bm)

It carries information at a gross rate of 22.82 Kbps.

Half Rate TCHIt carries information with half of full rate channels.

Control Channel

Basic structure of Control channel

1 2 3 4 . . . . . 10 11 . . . . . 21


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Actually in the above diagram S will be at slot 1 of next frame, F is frequency

correction channel which occurs every 10th burst. The next frame to S contains

service operators information.

Logical Control Channel (LCC) s are of three types

They are of the following types:

Broadcast Control Channel(BCCH)

Common Control Channel(CCCH)

Dedicated Control Channel(DCCH)

Broadcast Control Channel (BCCH)

The BCCH is a point-to-multipoint unidirectional control channel from the fixed

subsystem to MS that is intended to broadcast a variety of information to MSs,

including information necessary for the MS to register in the system. BCCH has 51

bursts. BCCH is dedicated to slot1 and repeats after every 51 bursts.

Broadcast Control Channel (BCCH) continually broadcasts, on the downlink,

information including base station identity, frequency allocations, and frequency-

hopping sequences.

The BCCH includes :

-- Frequency correction channel (FCCH) which is used to allow an MS to

accurately tune to a BS. The FCCH carries information for the frequency

correction of MS downlink. It is required for the correct operation of radio system.

This is also a point-to multipoint communication. This allows an MS to accuratelytune to a BS.

-- Synchronization channel (SCH), which is used to provide TDMA frame

oriented synchronization data to a MS. When a mobile recovers both FCCH and

SCH signals, the synchronization is said to be complete. SCH repeats for every 51

frames.

F S x X X X X X X X F S X X X X X X X X F S X X X


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The Synchronization Channel contains 2 encoded parameters:

BTS identification code (BSIC)

Reduced TDMA frame number (RFN).

Common Control Channel (CCCH)

A CCCH is a point-to-multipoint (bi-directional control channel) channel

that is primarily intended to carry signaling information necessary for access

management functions (e.g., allocation of dedicated control channels).

The CCCH includes:

-- paging channel (PCH), which is used to search (page) the MS in the downlink

direction

-- random access channel (RACH) which is used by MS to request of an

SDCCH either as a page response from MS or call origination/ registration from

the MS. This is uplink channel and operates in point-point mode(MS to BTS).Thisuses slotted ALOHA protocol..

-- access grant channel(AGCH) which is a downlink channel used to

assign a MS to a specific SDCCH or a TCH. AGCH operates in point-to-point

mode. A combined paging and access grant channel is designated as PAGCH.

Dedicated Control Channel (DCCH)

A DCCH is a point to point, directional control channel.

Two types ofDCCHs used are:

Standalone DCCH (SDCCH) is used for system signaling during idle periods

and call setup before allocating a TCH, for example MS registration, authentication

and location updates through this channel. When a TCH is assigned to MS this

channel is releasedAssociated Control Channel (ACCH) is a DCCH whose

allocation is linked to the allocation of a CCH

Data Transmission:

The GSM standard also provides separate facilities for transmitting digital

data. This allows a mobile phone to act like any other computer on the Internet,

sending and receiving data via the Internet Protocol.

Circuit-switched data protocols
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A circuit-switched data connection reserves a certain amount of bandwidth

between two points for the life of a connection, just as a traditional phone call

allocates an audio channel of a certain quality between two phones for the duration

of the call. Two circuit-switched data protocols are defined in the GSM

standard: Circuit Switched Data (CSD) and High-Speed Circuit-SwitchedData (HSCSD).

General Packet Radio Service (GPRS)

The General Packet Radio Service (GPRS) is apacket-switched data

transmission protocol, which was incorporated into the GSM standard in 1997. It is

backwards-compatible with systems that use pre-1997 versions of the standard.

GPRS does this by sending packets to the local mobile phone mast (BTS) on

channels not being used by circuit-switched voice calls or data connections.

Short Message Service (SMS)Short Message Service (more commonly known as text messaging) has

become the most used data application on mobile phones, with 74% of all mobile

phone users worldwide already as active users of SMS, or 2.4 billion people by the

end of 2007.
http://en.wikipedia.org/wiki/Circuit-switchedhttp://en.wikipedia.org/wiki/Circuit_Switched_Datahttp://en.wikipedia.org/wiki/High-Speed_Circuit-Switched_Datahttp://en.wikipedia.org/wiki/High-Speed_Circuit-Switched_Datahttp://en.wikipedia.org/wiki/General_Packet_Radio_Servicehttp://en.wikipedia.org/wiki/Packet-switchedhttp://en.wikipedia.org/wiki/Base_Transceiver_Stationhttp://en.wikipedia.org/wiki/SMShttp://en.wikipedia.org/wiki/Text_messaginghttp://en.wikipedia.org/wiki/Circuit-switchedhttp://en.wikipedia.org/wiki/Circuit_Switched_Datahttp://en.wikipedia.org/wiki/High-Speed_Circuit-Switched_Datahttp://en.wikipedia.org/wiki/High-Speed_Circuit-Switched_Datahttp://en.wikipedia.org/wiki/General_Packet_Radio_Servicehttp://en.wikipedia.org/wiki/Packet-switchedhttp://en.wikipedia.org/wiki/Base_Transceiver_Stationhttp://en.wikipedia.org/wiki/SMShttp://en.wikipedia.org/wiki/Text_messaging


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EMBEDDED SYSTEMS

We find ourselves to be surrounded by various types of embedded systems. Be it a

digital camera or a mobile phone or a washing machine, all of them has some kind

of processor functioning inside it. Associated with each processor is the embedded

software. If hardware forms the body of an embedded system, embedded processor

acts as the brain, and embedded software forms its soul. It is the embedded

software which primarily governs the functioning of embedded systems.

As time progressed, use of microprocessor-specific assembly-only as theprogramming language reduced and embedded systems moved onto C as the

embedded programming language of choice. C is the most widely used

programming language for embedded processors/controllers. Assembly is also

used but mainly to implement those portions of the code where very high timing

accuracy, code size efficiency, etc. are prime requirements.

Initially C was developed by Kernighan and Ritchie to fit into the space of 8K and

to write (portable) operating systems. Originally it was implemented on UNIX

operating systems. As it was intended for operating systems development, it can

manipulate memory addresses. Also, it allowed programmers to write very

compact codes. This has given it the reputation as the language of choice for

hackers too.


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An embedded system is a system that has software embedded into

hardware, which makes a system dedicated for an application (s) or specific part of

an application or product or part of a larger system.

We look around, we will find ourselves to be surrounded by

computing systems. Every year millions of computing systems are built destinedfor desktop computers but surprisingly, billions of computing systems are built

every year embedded within larger electronic devices and still goes unnoticed. Any

device running on electric power either already has computing system or will soon

have computing system embedded in it.

Today, embedded systems are found in cell phones, digital cameras,

camcorders, portable video games, calculators, and personal digital assistants,

microwave ovens, answering machines, home security systems, washing machines,

lighting systems, fax machines, copiers, printers, and scanners, cash registers,alarm systems, automated teller machines, transmission control, cruise control, fuel

injection, anti-lock brakes, active suspension and many other devices/ gadgets.

we find ourselves to be surrounded by various types ofembedded

systems. Be it a digital camera or a mobile phone or a washing machine, all of

them has some kind of processor functioning inside it. Associated with each

processor is the embedded software. If hardware forms the body of an embedded

system, embedded processor acts as the brain, and embedded software forms its

soul. It is the embedded software which primarily governs the functioning of

embedded systems.

As time progressed, use of microprocessor-specific assembly-only

as the programming language reduced and embedded systems moved onto C as the

embedded programming language of choice. C is the most widely used

programming language for embedded processors/controllers. Assembly is also

used but mainly to implement those portions of the code where very high timing

accuracy, code size efficiency, etc. are prime requirements.

Initially C was developed by Kernighan and Ritchie to fit into the

space of 8K and to write (portable) operating systems. Originally it was

implemented on UNIX operating systems. As it was intended for operating

systems development, it can manipulate memory addresses. Also, it allowed

programmers to write very compact codes. This has given it the reputation as the

language of choice for hackers too.
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SOFTWARE REQUIREMENTS

MPLAB X IDE

WHAT IS MPLABX IDE

MPLAB Integrated Development Environment (IDE) is a free, integrated toolset

for the development of embedded applications employing Microchip's PIC and ds

PIC microcontrollers. MPLAB IDE runs as a 32-bit application on MS

Windows

, is easy to use and includes a host of free software components for fastapplication development and super-charged debugging. MPLAB IDE also serves

as a single, unified graphical user interface for additional Microchip and third party

software and hardware development tools. Moving between tools is a snap, and

upgrading from the free software simulator to hardware debug and programming

tools is done in a flash because MPLAB IDE has the same user interface for all

tools.

Proteus (design software)


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Proteus is software for microprocessor simulation, schematic capture, and printed

circuit board (PCB) design. It is developed by Lab center Electronics.

The ProteusProfessional demonstration is intended for

prospective customers who wish to evaluate professional level products. It differs

from Proteus Lite in that it does not allow you to save, print or design your own

microcontroller based designs (you can however write your own software

programs to run on the existing sample design suite for evaluation), but does

include all features offered by the professional system including net list based PCB

design with auto-placement, auto-routing and graph based simulation. The

Proteus Design Suite combines schematic capture, SPICE circuit simulation, and

PCB design to make a complete electronics design system. Add to that the ability

to simulate popular micro-controllers running your actual firmware, and you have

a package that can dramatically reduce your development time when compared

with a traditional embedded design process

USART COMMUNICATION

Communication between two entities is important for the information flow to take

place. In general the information transport system can be parallel in which thecomplete byte of data is sent at a time, with each bit having a separate dedicated

line or it can be serial where only one communication line is available which is

shared by all the bits sequentially. The pros and cons of these two systems are

equivalent and selection between the two depends on the application.


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Data can be exchanged using parallel or serial techniques. Setup for parallel data

transfer is not cost effective but is a very fast method of communication. This

article explains serial communication of AVR microcontroller (ATmega16) with

PC. The data is transmitted from the controller using RS232 standard anddisplayed on the PC using Hyper Terminal.

There are two methods for serial data communication (i) Synchronous and (ii)

Asynchronous communication. In Synchronous communication method complete

block (characters) is sent at a time. It doesnt require any additional bits (start, stop

or parity) to be added for the synchronization of frame. The devices are

synchronized by clock. And in asynchronous communication data transmission is

done byte by byte i.e., one byte at a time. The additional bits are added to complete

a frame.

In synchronous communication the frame consists of data bits while in

asynchronous communication the total number of bits in a frame may be more than

the data bits.

USART Registers:

i. UCSRA: (USART Control and Status Register A)

RXC (USART Receive Complete): RXC flag is set to 1 if unread data exists inreceive buffer, and set to 0 if receive buffer is empty.

TXC (USART Transmit complete): TXC flag is set to 1 when data is completely

transmitted to Transmit shift register and no data is present in the buffer register

UDR.
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UDRE (USART Data Register Empty): This flag is set to logic 1 when the

transmit buffer is empty, indicating it is ready to receive new data. UDRE bit is

cleared by writing to the UDR register.

ii. UCSRB: (USART Control and Status Register B)

RXCIE: RX Complete Interrupt Enable,When 1 -> RX complete interrupt is enabled.

When 0 -> RX complete interrupt is disabled.

TXCIE: TX Complete Interrupt Enable,

When 1 -> TX complete interrupt is enabled

When 0-> TX complete interrupt is disabled

UDRIE: USART Data Register Empty Interrupt Enable,

When 1 -> UDRE flag interrupt is enabled.

When 0 -> UDRE flag interrupt is disabled.RXEN: Receiver Enabled,

When 1 -> USART Receiver is enabled.

When 0 -> USART Receiver is disabled.

TXEN: Transmitter Enabled,

When 1 -> USART Transmitter is enabled.

When 0 -> USART Transmitter is disabled.

iii. UCSRC: (USART Control and Status Register C)


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URSEL: USART Register select. This bit must be set due to sharing of I/O

location by UBRRH and UCSRC

UMSEL: USART Mode Select,

When 1 -> Synchronous Operation

When 0 -> Asynchronous OperationUPM[0:1]: USART Parity Mode, Parity mode selection bits.

USBS: USART Stop Select Bit,

When 0-> 1 Stop BitWhen 1 -> 2 Stop BitsUCSZ[0:1]: The UCSZ[1:0] bits

combined with the UCSZ2 bit in UCSRB sets size of data frame i.e., the number of

data bits. The table shows the bit combinations with respective character size.

HARDWARE REQUIREMENTS

Regulated Power Supply:

A regulated power supply is an embedded circuit; it converts unregulated AC into

a constant DC. With the help of a rectifier it converts AC supply into DC. It's

function is to supply a stable voltage (or less often current), to a circuit or device

that must be operated within certain power supply limits. The output from the

regulated power supply may be alternating or unidirectional, but is nearly always

DC (Direct Current)

ARCHITECTURAL OVERVIEW OF PIC 18F452 MICROCONTROLLER

High Performance RISC CPU:

C compiler optimized architecture/instruction set

- Source code compatible with the PIC16 and


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PIC17 instruction sets

Linear program memory addressing to 32 Kbytes

Linear data memory addressing to 1.5 Kbytes

Up to 10 MIPs operation:

- DC - 40 MHz osc./clock input- 4 MHz - 10 MHz osc./clock input with PLL active

16-bit wide instructions, 8-bit wide data path

Priority levels for interrupts

8 x 8 Single Cycle Hardware Multiplier

Peripheral Features:

High current sink/source 25 mA/25 mA

Three external interrupt pins Timer0 module: 8-bit/16-bit timer/counter with

8-bit programmable prescaler

Timer1 module: 16-bit timer/counter

Timer2 module: 8-bit timer/counter with 8-bit

period register (time-base for PWM)

Timer3 module: 16-bit timer/counter

Secondary oscillator clock option - Timer1/Timer3

Two Capture/Compare/PWM (CCP) modules.

CCP pins that can be configured as:

- Capture input: capture is 16-bit,

max. resolution 6.25 ns (TCY/16)

- Compare is 16-bit, max. resolution 100 ns (TCY)

- PWM output: PWM resolution is 1- to 10-bit,

max. PWM freq. @: 8-bit resolution = 156 kHz

10-bit resolution = 39 kHz

Master Synchronous Serial Port (MSSP) module,

Two modes of operation:

- 3-wire SPI (supports all 4 SPI modes)

- I2C Master and Slave mode

Peripheral Features (Continued):

Addressable USART module:


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- Supports RS-485 and RS-232

Parallel Slave Port (PSP) module

Analog Features:

Compatible 10-bit Analog-to-Digital Convertermodule (A/D) with:

- Fast sampling rate

- Conversion available during SLEEP

- Linearity 1 LSb

Programmable Low Voltage Detection (PLVD)

- Supports interrupt on-Low Voltage Detection

Programmable Brown-out Reset (BOR)

Special Microcontroller Features:

100,000 erase/write cycle Enhanced FLASH

Program memory typical

1,000,000 erase/write cycle Data EEPROM

memory

FLASH/Data EEPROM Retention: > 40 years

Self-reprogrammable under software control

Power-on Reset (POR), Power-up Timer (PWRT)

and Oscillator Start-up Timer (OST)

Watchdog Timer (WDT) with its own On-Chip RC

Oscillator for reliable operation

Programmable code protection

Power saving SLEEP mode

Selectable oscillator options including:

- 4X Phase Lock Loop (of primary oscillator)

- Secondary Oscillator (32 kHz) clock input

Single supply 5V In-Circuit Serial Programming

(ICSP) via two pins

In-Circuit Debug (ICD) via two pins

CMOS Technology:

Low power, high speed FLASH/EEPROM


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technology

Fully static design

Wide operating voltage range (2.0V to 5.5V)

Industrial and Extended temperature ranges

Low power consumption:- < 1.6 mA typical @ 5V, 4 MHz

- 25 A typical @ 3V, 32 kHz

- < 0.2 A typical standby current

PIN DIAGARAM


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DEVICE FEATURES


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FEATURES OF L293D IC:

600-mA Output Current Capability Per Driver

Pulsed Current 1.2-A Per Driver

Output Clamp Diodes for Inductive

Transient Suppression

Wide Supply Voltage Range

4.5 V to 36 V

Separate Input-Logic Supply

Thermal Shutdown

Internal ESD Protection

High-Noise-Immunity Inputs

Functional Replacement for SGS L293D

DESCRIPTION

The L293D is a quadruple high-current half-H driver designed to providebidirectional drive currents of up to 600-mA at voltages from 4.5 V to 36 V. It is

designed to drive inductive loads such as relays, solenoids, dc and bipolar stepping

motors, as well as other high-current/high-voltage loads in positive-supply

applications.

All inputs are TTL-compatible. Each output is a complete totem-pole drive

circuit with a Darlington transistor sink and a pseudo-Darlington source. Drivers

are enabled in pairs with drivers 1 and 2 enabled by 1,2EN and drivers 3 and 4

enabled by

3,4EN. When an enable input is high, the associated drivers are enabled, and their

outputs are active and in phase with their inputs.

External high-speed output clamp diodes should be used for inductive

transient suppression. When the enable input is low, those drivers are disabled, and

their outputs are off and in a high-impedance state. With the proper data inputs,


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each pair of drivers form a full-H (or bridge) reversible drive suitable for solenoid

or motor applications. A VCC1 terminal, separate from VCC2, is provided for the

logic inputs to minimize device power dissipation. The L293D is designed for

operation from 0C to 70C.

L293D is a dualH-bridge motor driver integrated circuit (IC). Motor drivers act ascurrent amplifiers since they take a low-current control signal and provide a

higher-current signal. This higher current signal is used to drive the motors.

L293D contains two inbuilt H-bridge driver circuits. In its common mode of

operation, two DC motors can be driven simultaneously, both in forward and

reverse direction. The motor operations of two motors can be controlled by input

logic at pins 2 & 7 and 10 & 15. Input logic 00 or 11 will stop the corresponding

motor. Logic 01 and 10 will rotate it in clockwise and anticlockwise directions,

respectively.

Enable pins 1 and 9 (corresponding to the two motors) must be high for motors to

start operating. When an enable input is high, the associated driver gets enabled.

As a result, the outputs become active and work in phase with their inputs.

Similarly, when the enable input is low, that driver is disabled, and their outputs

are off and in the high-impedance state.

DESIGN


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MICRO-CONTROLLER MODULE

An embedded microcontroller is a chip, which has a computer processor with allits support function (clocking and reset), memory (both program storage and

RAM), and I/O (including bus interfaces) built into the device. These built in

function minimize the need for external circuits and devices to the designed in the

final applications.

The improvements in micro-controller technology has meant that it is often more

costeffective, faster and more efficient to develop an application using a micro-

controller rather than discrete logic. Creating applications for micro-controllers is

completely different than any other development job in computing and electronics.In most other applications, number of subsystems and interfaces are available but

this is not the case for the micro-controller where the following responsibilities

have to be taken.

Power distribution

System clocking

Interface design and wiring

System Programming

Application programming

Device programming

There are two types of micro-controller commonly in use. Embedded micro-

controller is the micro-controller, which has the entire hardware requirement to run

the application, provided on the chip. External memory micro-controller is the

micro-controller that allows the connection of external memory when the program

memory is insufficient for an application or during the work a separate ROM (or

even RAM) will make the work easier.

GSM MODULE

GSM/GPRS module is used to establish communication between a

computer and a GSM-GPRS system. Global System for Mobile communication

(GSM) is an architecture used for mobile communication in most of the countries.

Global Packet Radio Service (GPRS) is an extension of GSM that enables higher


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data transmission rate. GSM/GPRS module consists of a GSM/GPRS modem

assembled together with power supply circuit and communication interfaces

(like RS-232, USB, etc) for computer. The MODEM is the soul of such modules.

Wireless MODEMs

Wireless MODEMs are the MODEM devices that generate, transmit or decode

data from a cellular network, for establishing communication between the cellular

network and the computer. These are manufactured for specific cellular network

(GSM/UMTS/CDMA) or specific cellular data standard

(GSM/UMTS/GPRS/EDGE/HSDPA) or technology (GPS/SIM). Wireless

MODEMs like other MODEM devices use serial communication to interface

with and need Hayes compatible AT commands for communication with the

computer (any microprocessor or microcontroller system).

GSM/GPRS MODEM is a class of wireless MODEM devices that are designed for

communication of a computer with the GSM and GPRS network. It requires a SIM

(Subscriber Identity Module) card just like mobile phones to activate

communication with the network. Also they have IMEI (International Mobile


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Equipment Identity) number similar to mobile phones for their identification. A

GSM/GPRS MODEM can perform the following operations:

The MODEM needs AT commands, for interacting with processor or controller,

which are communicated through serial communication. These commands are sent

by the controller/processor. The MODEM sends back a result after it receives a

command. Different AT commands supported by the MODEM can be sent by the

processor/controller/computer to interact with the GSM and GPRS cellular

network.

GSM has many benefits over current cellular systems.

The main problem now involves the COMP 128 algorithm problem. This problem

will be solved as newer technology gets phased in. The lack of extra encryption on

the telecommunications network doesnt pose as a major problem because any data

transfer on there will have the same security as the current public switched

telephone networks. Despite the current problems more and more cellular

companies will switch to GSM based standards. An estimated one billionsubscribers are expected by the end of 2003. As GSM slowly moves towards

3GSM, more problems and security issues will be resolved.
http://www.engineersgarage.com/tutorials/at-commandshttp://www.engineersgarage.com/tutorials/at-commands


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GSM COMMANDS:

commands are used to control MODEMs. AT is the abbreviation for Attention.

These commands come from Hayes commands that were used by the Hayes smart

modems. The Hayes commands started with AT to indicate the attention from theMODEM. The dial up and wireless MODEMs (devices that involve machine to

machine communication) need AT commands to interact with a computer. These

include the Hayes command set as a subset, along with other extended AT

commands.

AT commands with a GSM/GPRS MODEM or mobile phone can be used to

access following information and services:

1. Information and configuration pertaining to mobile device or MODEM and SIMcard.

2. SMS services.

3. MMS services.

4. Fax services.

5. Data and Voice link over mobile network.

Explanation of commonly used AT commands:

1) AT - This command is used to check communication between the module

and the computer.

For example,


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As the command AT+CMGS and serial number of message are entered, SMS is

sent to the particular SIM.

For example,

AT+CMGS=1OK

5) ATD - This command is used to dial or call a number.

SYNTAX: ATD(Enter)

For example,

ATD123456789

6) ATA - This command is used to answer a call. An incoming call is indicatedby a message RING which is repeated for every ring of the call. When the call

ends NO CARRIER is displayed on the screen.

SYNTAX: ATA(Enter)

As ATA followed by enter key is pressed, incoming call is answered.

For example,

RING

RING

ATA

7) ATH - This command is used to disconnect remote user link with the GSM

module.

SYNTAX: ATH (Enter)

DC MOTOR MODULE


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A light-emitting diode (LED) is a semiconductor light source .LEDs are used as

indicator lamps in many devices and are increasingly used for general lighting.

Appearing as practical electronic components in 1962, early LEDs emitted low-

intensity red light, but modern versions are available across the visible, ultraviolet,

and infrared wavelengths, with very high brightness.

PROGRAM


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#include

#pragma config OSC=XT, WDT=OFF, LVP=OFF

void txd(unsigned char ch);

unsigned char rxd();

int i,v1=0,v2=0,v3=0,v4=0;

char

mobno[20],msg[50],x,cmp1[]="ON1",cmp2[]="OF1",cmp3[]="ON2",cmp4[]="OF

2";

void delay1(unsigned int z){

unsigned int i;

unsigned char j;

for(i=0;i


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}

void Tx_String(const rom char *str)

{

while((*str)!='\0')

{

txd(*str);

str++;

}

}

int Read_SMS()

{

v1=0;v2=0;v3=0;v4=0;

while(rxd()!='+');{

while(rxd()!='C');

{

while(rxd()!='M');

{

while(rxd()!='T');

{

while(rxd()!='I');

{

while(rxd()!=':');

{

while(rxd()!=',');

x=rxd();

Tx_String("AT+CMGR=");

txd(x);

txd('\r');

while(rxd()!='?');

for(i=0;i


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v1=1;

}

if(msg[i]!=cmp2[i])

{

v2=1;

}

if(msg[i]!=cmp3[i])

{

v3=1;

}

if(msg[i]!=cmp4[i])

{

v4=1;

}

}if(v1==0)

{

PORTB |= (1


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int main(void)

{

TRISB = 0x00;

USART_Init();

delay1(10);

Tx_String("AT\r");

PORTB = 0x00;

while(1)

{

Read_SMS();

Tx_String("AT+CMGF=1\r");

delay1(100);

Tx_String("AT+CMGD=1\r");

delay1(100);

Tx_String("AT+CMGD=2\r");delay1(100);


delay1(100);


delay1(100);


delay1(1000);

}

}


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INTEGRATING ALL THE MODULES:

THE integrating all the modules deals with effective data communication

between the modules used in the project. The modules have been connectedthrough wires and communicated with help of electrical signals.

Initially the gsm module and the microcontroller is powered by the

regulated power supply ,then the gsm module contains the SIM , as we inserted in

the gsm module the SIM detected the signal and detection is indicated through the

led light blinking .

The TX and RX pins of the gsm module and microcontroller are

connected to transfer the commands to and fro, to be operated and the resultant

output signal is fed to the load using the driving integrated circuit ic i.e, dc motorand the led light emitting diodes

The GSM module is integrated with the microcontroller and the dc

motor and light emitting diodes are also integrated with microcontroller , as we

sends the SMS from any GSM mobile to the SIM contains in the GSM module

receives the message and reads the password contains in sms and matches up with

the password in the microcontroller program through TX and RX pins , if the

authentication is granted then the data matches the program execute and the

required load can be switched on and off throughout anywhere on the world .

The message contains four different passwords to access the

appliances that is for switching on and switching off the dc motor and the another

two passwords for the switching on and of the light emitting diodes.

When the gsm module reads the receivesd message and after

completion of execution the message will be deleted from the memory of the SIM

finally . this process can be repeated as many times

SCREENSHOTS OF THE PROJECTS


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FUTURE ENHANCEMENTS AND BENIFITS:

The future implications of the project are very great considering the amount of

time and resources it saves.

The project we have undertaken can be used as a reference or

as a base for realizing a scheme to be implemented in other projects of greater level

such as weather forecasting, temperature updates, device synchronization, etc.

The project itself can be modified to achieve a complete Home

Automation System which will then create a platform for the user to interface

between himself and his household.

CONCLUSION


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The project we have undertaken has helped us gain a better perspective on various

aspects related to our course of study as well as practical knowledge of electronic

equipments and communication. We became familiar with software analysis,

designing, implementation, testing and maintenance concerned with our project.

The extensive capabilities of this system are what make it so

interesting. From the convenience of a simple cell phone, a user is able to control

and monitor virtually any electrical devices. This makes it possible for users to rest

assured that their belongings are secure and that the television and other electrical

appliances was not left running when they left the house to just list a few of the

many uses of this system.

The end product will have a simplistic design making it easy for

users to interact with. This will be essential because of the wide range of technicalknowledge that homeowners have

We have gained practical knowledge of electronic equipments,

communications, software analysis and designing. A new concept and

implementation of an effective GSM based home security system. Meet the need

to automate life to give advantage of the technological advancement.

when the number of mobile phone users growing at a high rate,

this system makes use of the mobile networks to provide the users with a simple

and cheap home automation system.

REFERENCES:

TEXTUAL REFERENCES

1. Mazidi, Muhammad ali, The 8051 Microcontroller and Embedded

Systems,Second Edition, Prentice Hall, 2007

WEB REFERENCES

1. www.embedtronics.com, 2. www.forum.nokia.com,


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http://www.embedtronics.com/

gsm based home automation working file finished

Documents