Final Paper F

EMBEDED SYSYEMS SECTION: GLOBAL SYSTEM FOR MOBILE TECHNOLOGY (GSM)

BY NANDEESH.V NANDIKESH.H.P ELECTRONICS AND COMMUNICATION ENGG

SIDDAGANGA INSTITUTE OF TECHNOLOGY TUMKUR KARNATAKA

EMAIL: [email protected] PHONE: 91-9742020079

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ABSTRACT:

Embedded systems have grown tremendously in recent years, not only in their popularity but also in their complexity. Gadgets are increasingly becoming intelligent and autonomous. Refrigerators, air-conditioners, automobiles, mobile phones etc are some of the common examples of devices with built in intelligence. These devices function based on operating and environmental parameters. The intelligence of smart devices resides in embedded systems. An embedded system, in general, in co-operates hardware, operating systems, low-level software binding the operating system and peripheral devices, and communication software to enable the device to perform the pre-defined functions. An embedded system performs a single, well-defined task, is tightly constrained, is reactive and computes results in real time. The main principle behind this PPT is to develop a module for Home Automation and Security system mainly in a Home and Industry using Industrial Sensors and transfer the related sensed data using the latest Global System for Mobile Technology (GSM), which intimates the unauthorized entry\Smoke, and Temperature to the Embedded -Controller. The Embedded -Controller maintains the security system, so its present information sends to the user for further investigation.

1.1 INTRODUCTION TO EMBEDDED SYSTEMS

their

complexity.

becoming

Gadgets

intelligent

are

and

increasingly autonomous.

Refrigerators, air-conditioners, automobiles, mobile Embedded systems have grown tremendously in

phones etc are some of the common examples of

recent years, not only in their popularity but also in

devices with built in intelligence. These devices

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function based on operating and environmental

environment and must compute certain

parameters.

results in real time without delay.

The intelligence of smart devices resides in embedded systems. An embedded system, in general, in cooperates hardware, operating systems, low-level software binding the operating system and

peripheral

devices,

and

communication

software to enable the device to perform the predefined functions. An embedded system performs a single, well-defined task, is tightly constrained, is reactive and computes results in real time.

embedded systems: functioned:

An

and the kinds of microprocessors used in them are quite varied. A list of some of the common microprocessor families is the ZILOG Z8 family, Intel 805/80188/x 86 families, Motorola 68k family and the PowerPC family.The software for the embedded

systems

is

called

firmware. The

firmware will be written in assembly languages for time or or using higher-level languages like C or embedded C.

Let us take a detailed look at these features of

 Single

All embedded systems need a microprocessor,

1.2 HOME AUTOMATION AND SECURITY SYSTEM

embedded

system executes a specific program

The main principle of this project is to develop a

repeatedly. For example, a pager is

module for Home Automation and Security system

always a pager. In contrast a desktop

mainly in a Home and Industry using Industrial

system executes a variety of programs

Sensors and transfer the related sensed data using

like spreadsheets, word processors, etc.

the latest Global System for Mobile Technology

However there are exceptions where in

(GSM),

an embedded system’s program is

entry\Smoke, and Temperature to the Embedded

updated with newer program versions.

-Controller. The Embedded -Controller maintains

Cell phones are examples of being

the security system, so its present information sends

updated in such a manner.

to the user for further investigation.

which

intimates

the

unauthorized

 Tightly constrained: All computing

The Home Automation and security system, The

systems have constraints on design

Embedded-Controller module is to control the

metrics but those on

embedded

whole module for security purpose. The GSM TX-

systems can be especially tight. A

Modem, The GSM RX-Modem, The unauthorized

design metric is a measure of an

entry, fire detected and variation in the temperature

implementation’s features, such as cost,

after being sensed will be fed to the Embedded-

size performance and power.

Controller which is responsible for processing the

 Reactive

and

real

time:

Many

data and gives input to the GSM Modem at Disaster

embedded systems must continually

Base Station. The transmitted data will be received

react to changes in the system’s

through the Short Messaging Service (SMS) at the 3

GSM RX-Modem. The GSM-RX Modem decodes

The system has been designed which is based on

the data and transfers it to the user, which maintains

wireless communication embedded system. The

the security for Home or industry. Relay is used to

design provides the necessary control for the

control the device.

working of home automation and security system.

In Home automation, the devices consist of GSM modem, microcontroller, sensors, relays, memory and displays. If the user want s to control some devices in his house he/she have to send the SMS indicating the operation of the device and then the system password, while the MODEM embedded with the system microcontroller receives SMS the microcontroller will read the SMS and check for

The control software program is written in ‘Embedded C’.The program has the capability of sending and receiving the SMS from and to the user mobile via GSM modem to tell that unauthorized entry/smoke has detected in case of security system and to control some devices in case of automation system respectively. The program also provides the display of current status of the system.

the password the user had sent with the SMS, the passwords

are

stored

in

memory,

so

the

microcontroller will read the password from the memory and compares with the message password.

The fundamental requirements of the system design are as follows: •

from and to the user mobile.

If the password is correct then it will check whether the message is for switch ON or OFF the devices.

GSM modem to send and receive the SMS

•

According to the received message the controller

Sensors

to

detect

unauthorized

entry/smoke.

will switch on/off the relay. • In Security system, the device connected to the

ADC

to

convert

sensed

voltage

to

correspond digital values.

sensors. When somebody had entered home forcibly, the sensor connected to the door will

•

the system.

detect the presence of person, and it will give an interrupt to the microcontroller. Then according to the program load in the flash, the controller will find out from which sensor the interrupt had came,

LCD display to display the current status of

•

UART for the serial communication.

•

Microcontroller for the entire operation of

then it will sent SMS to the owners mobile or

the system.

police by retrieving the phone numbers from memory where numbers are stored in it.

•

A range of voltage levels to compare with the sensed voltage.

2.1 SYSTEM DESCRIPTION

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2.2 BLOCK DIAGRAM

TRANS-RECEIVER OF USER

TRANS-RECEIVER OF SYSTEM

Fig 1. Block Diagram of Home Automation & Security System

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2.3 BLOCK DIAGRAM DESCRIPTION

LCD’s can add a lot to your application in terms of providing an useful interface for the user, debugging an application or just giving it a

COMPONENT DETAILS:

"professional" look. The most common type of

POWER SUPPLY:

LCD controller is the Hitachi 44780 which provides

The microcontroller and other devices get power supply from AC to Dc adapter through 7805, 5 volts regulator. The adapter output voltage will be 12V DC non regulated. The 7805/7812 voltage regulators are used to convert 12 V to 5V/12V DC. MICROCONTROLLER-AT89C52:

CMOS 8-bit microcontroller with 8K bytes of insystem programmable Flash memory. The device is using

Atmel’s

high-density

nonvolatile memory technology and is compatible with the industry- standard 80C51 instruction set and pinout. LCD (LIQUID CRYSTAL DISPLAY):

and an LCD. Using this interface is often not attempted

by

inexperienced

designers

and

programmers because it is difficult to find good documentation

on

the

interface,

initializing

interface can be a problem and the displays themselves are expensive.LCD has single line

The AT89C52 is a low-power, high-performance

manufactured

a relatively simple interface between a processor

display, Two-line display, four line display. Every line has 16 characters. RS 232 CONVERTOR (MAX 232N): This is the device, which is used to convert TTL/RS232 vice versa. RS-232 was created for one purpose, to interface between Data Terminal Equipment (DTE) and Data Communications Equipment (DCE) employing serial binary data interchange. So as stated the DTE is the terminal or computer and the DCE is the modem or other communications device. RS-232 pin-outs for IBM compatible computers are shown below. There are two configurations that are typically used: one for a 9-pin connector and the other for a 25-pin connector. EXTERNAL EEPROM MEMORY (2K BYTES): These memory devices are used to store the data for off line process. The AT24C02A provides 2048bits

of

serial

electrically

erasable

and

programmable read only memory (EEPROM) 6

organized as 256words of 8 bits each. The device is

embedded or plugged into any application. The

optimized

and

Smart Modem can be controlled and customized to

commercial applications where low power and low

various levels by using the standard AT commands.

voltage operation are essential. The AT24C02Ais

The modem is fully type-approved, it can speed up

available in space saving 8-pin PDIP.

the operational time with full range of Voice, Data,

for

use

in

many

industrial

Fax and Short Messages (Point to Point and Cell Broadcast), the modem also supports GPRS (Class SENSORS: Here we are using 3 types of sensors. PIR sensor

2*) for spontaneous data transfer. RELAYS:

(Passive infra red sensor) is used to detect the

A relay is used to isolate one electrical circuit

movement. Smoke sensor (Passive infra red

from another. It allows a low current control circuit

sensor) is used to detect the presence of smoke and

to make or break an electrically isolated high

the temperature sensor is used to detect the

current circuit path. Here, it act as a switch between

temperature.

the microcontroller and a device.

GSM MODEM: Semen’s GSM/GPRS Smart Modem is a multifunctional, ready to use, rugged unit that can be

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2.4 CIRCUIT DIAGRAM

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3.1 SOFTWARE DESCRIPTION 9

Home automation and security system without software is of little use and hardware with poor software can be worse. The software developed for this project is user friendly. The code is written in ‘EMBEDDED C (KEIL SOFTWORE).

the elements of the 8051 architecture. These C programs are referred as Embedded C programs.  UP loader 4.0: This Up-loader is used to flash some of the Micro-Controllers. It Supports only 8051, Atmel

Software requirements:

89c51, 89c52 & 89c55wd. This Up-Loader is used

 Keil µVision2 IDE:

to flash the Microcontroller via Hex file and then it

Keil µVision2 IDE (Integrated Development Environment) is a Windows based front end for the C Compiler and assembler. Keil µVision2 is used for writing embedded C programswhich is

verify the written Hex code to the flash memory. The flashing time is faster when we use the uploader. This up-loader is very much compact. Embedded C:

explained later.. Embedded C is a high level language, which includes many aspects of the ANSI (American

National

Standard

Institute)

C

programming language. Standard libraries are altered or enhanced to address the peculiarities of an embedded target processor.  Cx51 cross compiler: Cx51 is a cross compiler to compile C programs for your target 8051 environment and provides several extensions to ANSI Standard C to support

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The C programming language is a generalpurpose programming language that provides code efficiency, elements of structured programming, and a rich set of operators. Its generality combined with its absence of restrictions, makes C a convenient and effective programming solution for a wide variety of software tasks. Many applications can be solved more easily and efficiently with C than with other more specialized languages. Cx51 is not a universal C compiler adapted for the 8951 target.

3.3 FLOW CHART

HOME AUTOMATION SYSTEM:

START

INTIALIZE MODEM

INTIALIZE µC

POLLING

IS PASSWOR D

CHECK FOR DEVICE OPERATION SENT BY USER

A

11

A

IS D1/D2

TURN ON THE DEVICE D1/D2

IS D1/D2

TURN ON THE DEVICE D1/D2

STOP

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SECURITY SYSTEM:

START

CHECK FOR DEVICE STATUS

STORE THE USER MOBILE NUMBER

POLLING

ONE OF THE SENSORS GET INTERUPTED

µC WILL GET INTERRUPT

ACCORDING TO CODE ACTION, CONTROLLER SENDS SMS TO USER MOBILE

STOP

MICROCONTROLLER 13

nonvolatile memory programmer. The Atmel AT89C52 is a powerful microcomputer, which provides a highly flexible and cost-effective solution to many embedded control applications. It also provides 32 I/O lines, 256bytes of RAM for data storage.

FEATURES:

Fig 4 pin configuration of AT89C52

•

Compatible with MCS-51™ Products

•

8K Bytes of In-System Reprogrammable Flash

Figure above shows the pinout of 89C52

Memory

µc.The AT89C52 is a low-power, high-performance

•

Endurance: 1,000 Write/Erase Cycles

CMOS 8-bit microcomputer with 8K bytes of Flash

•

Fully Static Operation: 0 Hz to 24 MHz

•

Three-level Program Memory Lock

•

256 x 8-bit Internal RAM

technology and is compatible with the industry-

•

32 Programmable I/O Lines

standard MCS-51 instruction set and pin out. The

•

Three 16-bit Timer/Counters

on-chip Flash allows the program memory to be

•

Six Interrupt Sources

programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s

high-density

nonvolatile

memory

reprogrammed in-system or by a conventional

BLOCK SCHEMATIC OF AT89C52:

14

Fig 5 Block schematic of AT89C52 1. The lower 128bytes of RAM (addresses 00H to 7FH) are directly and indirectly addressable. The four segments are: 15

2. The upper 128 bytes of RAM (addresses 80H to

•

FFH) are indirectly addressable only. 3.

The special function registers, (SFR’s)

B REGISTER: The B register is used during multiply

and

divide

operations

for

other

(addresses 80H to FFH) are directly addressable

instructions it can be treated as another

only.

scratch pad register.

4. 256 bytes expanded RAM (ERAM, 00H-FFH) is

•

PSW (PROGRAM STATUS REGISTER):

indirectly accessed by MOVX instruction and with The PSW contains several status bits that reflect

the EXTRAM bit cleared.

the current state of the cpu. The psw resides in the Either direct or indirect addressing can access the lower 128 bytes.

SFR space.

The upper 128 bytes can be

accessed indirect addressing only. The upper 128

•

bytes occupy the same address but are physically separate from the SFR space. When an instruction accesses an internal location above address 7FH, the CPU knows whether the accesses is to the upper 128 bytes of data RAM or to SFR space by the direct addressing mode used in the instruction. Instructions that use direct addressing access SFR

STACK POINTER: This is of 8-bit wide. It is incremented before data

is stored during PUSH and CALL executions. While the stack pointer may any where in on chip RAM the stack pointer is initialized to 07h after a reset. This causes the stack to begin at location 08h. •

DATA POINTER (DPTR):

space. For example MOV OAOH, #data. This consists of a high type and a low byte. Its SFR (SPECIAL FUNCTION REGISTER): A map of the on-chip memory area is called the special function registers (SFR) space. Note that in the SFR's not all the addresses are occupied.

intended function is to hold a 16-bit address. It may be manipulated as a 16-bit register or as two independent 8-bit registers. •

PORTS 0 TO 3:

Unoccupied addresses are not implemented on the Read accesses to these addresses will in

P0, P1, P2, and P3 are the SFR of ports 0,1,2 & 3

general return random data and write accesses will

respectively. Writing a one of a port SFR causes the

have no-effect.

port output pin to switch low. When used as an

chip.

The functions of SFR's are

described as follows:

input, the external state of a pin will be held in the port SFR.

•

ACCUMULATOR: •

SERIAL DATA BUFFER:

Acc is the accumulator register. The mnemonics for accumulator, specific Instructions. However,

The serial buffer is actually two separate registers

refer to the accumulator simply as "A".

transmit buffer and a receive buffer. When data is

16

involved to SBUF. It goes to transmit buffer and is

The Global System for Mobile communications

held for serial transmission. When data is moved

(GSM: originally from Group Special Mobile) is

from SBUF. It comes from SBUF. It comes the

the most popular standard for mobile phones in the

receive buffer.

world. Over 2 billion people use GSM service

•

across more than 212 countries and territories. Its

TIMER REGISTER BASIC TO 89C51:

ubiquity makes international roaming very common

Register pins (TH0, TL0), (TH1, TL1), (TH2, TL2)

between

mobile

are 16-bit counting registers for timer/counters 0,

subscribers to use their phones in many parts of the

1&2, respectively.

world.

GSM

phone

differs

operators,

significantly

enabling from

its

predecessors in that both signaling and speech •

CONTROL REGISTER FOR THE 89C51:

SFR, IP, IE, TMOD, SCON and PCON contain and status

bits

for

the

interrupt

system.

The

timer/counters and the serial port.

channels are digital call quality, and so is considered a second generation (2G) mobile phone system.

This

has

also

meant

that

data

communication was built into the system from the 3rd Generation Partnership Project (3GPP). The key advantage of GSM systems to consumers has been higher digital voice quality and low cost

4.2 GLOBAL SYSTEM FOR MOBILE COMMUNICATION

alternatives to making calls, such as the Short message

service

(SMS,

also

called

"text

messaging"). The advantage for network operators has been the ease of deploying equipment from any vendors that implements the standard. [3] Like other cellular standards, GSM allows network operators to offer roaming services so that subscribers can use their phones on GSM networks all over the world. Newer versions of the standard were backward compatible with the original GSM phones. For example, Release '97 of the standard added packet data capabilities, by means of General Packet Radio Service (GPRS). Release '99 introduced higher speed data transmission using Enhanced Data Rates for GSM Evolution (EDGE). History of GSM 17

The growth of cellular telephone systems started

Europe.

In

1989,

GSM

responsibility

was

in the early 1980s, particularly in Europe. The lack

transferred to the European Telecommunications

of a technological standardization prompted the

Standards Institute (ETSI), and phase I of the GSM

European

and

specifications was published in 1990. Radiolinja in

Telecommunications Administrations (CEPT) to

Finland launched the first GSM network in 1991.

create the Group Special Mobile (GSM) in 1982

By the end of 1993, over a million subscribers were

with the objective of developing a standard for a

using GSM phone networks being operated by 70

mobile telephone system that could be used across

carriers across 48 countries.

GSM Modem

GSM. The data communication was of secondary

Conference

of

Postal

importance to this network but to support this also, designers have considered the circuit switching

Anten

Serial

itself the mechanism for transmitting data packets.

GSM MODEM FIG 6 SIMPLE BLOCK DIAGRAM OF GSM Microcontr

GSM Architecture

MODEM FIG 6 GSM Architecture

GSM modem is the medium by which the user can interact with the module. It is used to send and receive SMS based on which appropriate actions

•

are taken by the controller. Figure above a simple block diagram of it.

Figure above shows the schematic of GSM Architecture. The Mobile Station (MS) directly interacts with one of the

GSM Network

Base Transceiver Stations, which in

The GSM network was designed keeping in mind

turn interacts with a Base Station

the voice activities of the user and its main purpose

Controllers (BSC). BTS and BSC

was to provide voice connectivity like Public

combined together forms the BSS.

Switched Telephone Networks but with mobility.

More than one BTSs are connected

So Call Processing activities were the major criteria

with one BSC. The BSC further

to decide and fix the implementation standards of

interacts

Handset

HLR/ VLR

UM A-bis

BSC

A

MSC

SS7 PSTN

BTS

OMC (Operation & Maintenance Center) Operation Terminal

18SIM card Mobile station

X.25

Radio sub-system

Network sub-system

Data Terminal

PSTN

with

Mobile

Station

•

Controller (MSC), which is the heart of

If the SIM detect pin indicates “present”,

the GSM network. MSC further gives

and the inserted Card is not a SIM Card,

connectivity to the PSTN and other

the response to AT+CPIN? is CME

PLMNs. MSC is also responsible to

ERROR 10.

interact with HLR and VLR, which

•

These last two states are not given

form the Permanent and Temporary

immediately

data bases for all the subscribers static

initialization. Between the hardware SIM

and

detect pin indicating “present” and the

dynamic

information.

due

to

background

previous results the AT+CPIN? sends “+CME ERROR: 515” (Please wait, init in progress). •

When the SIM detect pin indicates card absence, and if a SIM Card was previously

General Behaviors

inserted, an IMSI detach procedure is SIM Insertion, SIM Removal

performed, all user data is removed from the product (Phonebooks, SMS etc.). The

SIM card Insertion and Removal procedures are supported. There are software functions relying on positive reading of the hardware SIM detect pin.

product then switches to emergency mode. Attention (AT) Commands

This pin state (open/closed) is permanently

GSM modem can be controlled by standard set of

monitored. When the SIM detect pin indicates that

AT (Attention) commands. These commands can be

a card is present in the SIM connector, the product

used to control majority of the functions of GSM

tries to set up a logical SIM session. The logical

modem. Few commands used in this project are

SIM session will be set up or not depending on

described in the chapter APPENDIX.

whether the detected card is a SIM Card or not. The AT+CPIN?

command

delivers

the

following

.

5. ADVANTAGES AND APPLICATIONS

responses: •

If the SIM detect pin indicates “absent”, the response to AT+CPIN? Is “+CME ERROR 10” (SIM not inserted).

•

ADVANTAGES:  We can access the devices such as home appliances remotely.

If the SIM detect pin indicates “present”, and the inserted Card is a SIM Card, the

 We can detect the unauthorized

response to AT+CPIN? is “+CPIN: xxx”

smoke/entry even if we are not present in

depending on SIM PIN state.

home.  Easy to implement. 19

APPLICATIONS:

BIBLIOGRAPHY

Automation and security system is required at: Frank Wahid, Embedded System  Home

Muhammad Ali Mazidi, The 8051 Microcontroller and Embedded System

 Office

V.K. Mehta, Principles of Electronics  Industry  Power plants  Other valuable areas

6. CONCLUSION

The designed home automation and security system has been successfully demonstrated by connecting GSM modem and sending/receiving the SMS by using GSM mobile from/to the system via GSM modem. The LCD display will display the correct current status of the system. This project is easy to implement and it has become one of the modern wireless privacy system. 7. SCOPE FOR FURTHER IMPLEMENTATIONS



In future we can add a multimedia camera to see what is going inside the home by sitting in office or some where.

 We can voice recorder for IR Sensor’s detection

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