23-07-2014, 11:28 AM
GSM Based Control System
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INTRODUCTION
GSM based Control System” implements the emerging applications of the GSM
technology. Using GSM networks, a control system has been proposed that will act as an
embedded system which can monitor and control appliances and other devices locally
using built-in input and output peripherals.
Remotely the system allows the user to effectively monitor and control the house/office
appliances and equipments via the mobile phone set by sending commands in the form of
SMS messages and receiving the appliances status. The main concept behind the project
is receiving the sent SMS and processing it further as required to perform several
operations. The type of the operation to be performed depends on the nature of the SMS
sent. The principle in which the project is based is fairly simple. First, the sent SMS is
stored and polled from the receiver mobile station and then the required control signal is
generated and sent to the intermediate hardware that we have designed according to the
command received in form of the sent message.
We have selected a particular Nokia mobile set (Nokia 3310) for our project. The
messages are sent from the mobile set that contain commands in written form which are
then processed accordingly to perform the required task. A microcontroller based system
has been proposed for our project. There are several terminologies that are used
extensively throughout this project report.
GSM (Global System for Mobile Communications): It is a cellular communication
standard.
Problem Statement
Technology has advanced so much in the last decade or two that it has made life more
efficient and comfortable. The comfort of being able to take control of devices from one
particular location has become imperative as it saves a lot of time and effort. Therefore
there arises a need to do so in a systematic manner which we have tried to implement
with our system. The system we have proposed is an extended approach to automating a
control system.
With the advancement and breakthroughs in technology over the years, the lives of
people have become more complicated and thus they have become busier than before.
With the adoption of our system, we can gain control over certain things that required
constant attention. The application of our system comes in handy when people who forget
to do simple things such as turn ON or OFF devices at their home or in their office, they
can now do so without their presence by the transmission of a simple text message from
their mobile phone. This development, we believe, will ultimately save a lot of time
especially when people don’t have to come back for simple things such as to turn
ON/OFF switches at their home or at their office once they set out for their respective
work.
Description
The figure shown above is the simple block diagram of our project. It is a simple
illustration of how we have implemented our project and the various parts involved in it.
From the above representation, the first Mobile station is used as a transmitting section
from which the subscriber sends text messages that contain commands and instructions to
the second mobile station which is based on a specific area where our control system is
located. The mobile phone as indicated in the block diagram is a Nokia 3310 mobile set.
The received SMS message is stored in the SIM memory of the phone and then extracted
by the microcontroller and processed accordingly to carry out specific operations. The
relay driver (BUFFER ULN2003) is used to drive the relay circuits which switches the
different appliances connected to the interface. The LCD is used to indicate the status of
the operation performed by the microcontroller and also its inclusion makes the overall
system user-friendly.
The input from different sensors are feed to micro-controller and processed to operate
respective task semi autonomously and autonomousl
SYSTEM SPECIFICATION
The system specification shows the description of the function and the performance of
system and the user. The scope of our project “GSM Based control system” is immense.
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 the household.
Major Constraints
Along the course of project completion we encountered various problems and obstacles.
Not everything that we had planned went smoothly during the project development span.
Also we had a limited amount of time for its completion so we were under a certain
amount of pressure as well. We had to start from the research phase at the beginning and
needed to gain knowledge on all the devices and components that we had intended to use
for our project. Other phases of the project included coding, debugging, testing,
documentation and implementation and it needed certain time for completion so we really
had to manage the limited time available to us and work accordingly to finish the project
within the schedule
DESIGN
An embedded microcontroller is a chip, which has a computer processor with all its
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
ATMEL Micro-controller
The AT89C52 is a low-power; high performance CMOS 8-bit microcomputer with 8K
bytes of Flash programmable and erasable read only memory (PEROM). The device is
manufactured using Atmel’s high-density nonvolatile memory technology and is
compatible with the industry-standard 80C51 and 80C52 instruction set and pinout. The
on-chip Flash allows the program memory to be reprogrammed in-system or by a
conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with
Flash on a monolithic chip, the Atmel AT89C52 is a powerful microcomputer which
provides a highly-flexible and cost-effective solution to many embedded control
applications
Temperature Sensor
The two main types of semiconductor temperature sensors are temperature sensitive
voltage sources and temperature-sensitive current sources. An example of the first type is
the National LM35. The voltage output from this circuit increases by 10 mV for each
degree centigrade that its temperature is increased. If the output is connected to a
negative reference voltage Vs, the sensor will give a meaningful output for temperature
range of -55 to +150 degree centigrade. The output is adjusted to 0V for 0 degree
centigrade. The output voltage can be amplified to give the voltage range we need for a
particular application. The accuracy of this device is about 1 degree centigrade.
A thermocouple junction made of iron and constantan, commonly called a J
thermocouple, has a useful temperature range of about -184 to 760 degree centigrade.
Thermocouples can be made small, rugged and stable, however, they have problems like
the output is very small and must be amplified a great deal to bring it up into range where
it can drive an A/D converter. So, we used LM35 in our system.
GSM TECHNOLOGY AND SHORT MESSAGING SERVICE
GSM is a global system for mobile communication GSM is an international digital
cellular telecommunication. The GSM standard was released by ETSI (European
Standard Telecommunication Standard) back in 1989. The first commercial services were
launched in 1991 and after its early introduction in Europe; the standard went global in
1992. Since then, GSM has become the most widely adopted and fastest-growing digital
cellular standard, and it is positioned to become the world’s dominant cellular standard.
Today’s second-generation GSM networks deliver high quality and secure mobile voice
and data services (such as SMS/ Text Messaging) with full roaming capabilities across
the world.
GSM platform is a hugely successful technology and as unprecedented story of global
achievement. In less than ten years since the first GSM network was commercially
launched, it become, the world’s leading and fastest growing mobile standard, spanning
over 173 countries. Today, GSM technology is in use by more than one in ten of the
world’s population and growth continues to sour with the number of subscriber
worldwide expected to surpass one billion by through end of 2003.
SHORT MESSAGE SERVICE
SMS stands for Short Message Service. It is a technology that enables the sending and
receiving of message between mobile phones. SMS first appeared in Europe in 1992. It
was included in the GSM (Global System for Mobile Communication) standards right at
the beginning. Later it was ported to wireless technologies like CDMA and TDMA. The
GSM and SMS standards were originally developed by ETSI. ETSI is the abbreviation
for European Telecommunication Standard Institute. Now the 3GPP (Third Generation
Partnership Project) is responsible for the development and maintenance of the GSM and
SMS standards.
SOFTWARE INTRODUCTION
The software for our project was developed using a simple high level language tool in C.
The software extracts the sent message from the SIM location at a regular interval and
processes it to control the different appliances connected within the interface. We have
made use of the Nokia F-Bus protocol to communicate with the mobile phone set. Most
Nokia phones have F-Bus and M-Bus connections that can be used to connect a phone to
a PC or in our case a microcontroller. The connection can be used for controlling just
about all functions of the phone, as well as uploading new firmware etc. This bus will
allow us to send and receive SMS messages.
The very popular Nokia 3310/3315 has the F Bus and M Bus connection under the
battery holder. This is a bit of a pain to get to and requires a special cable to make the
connection.The software for our project was developed using a simple high level language tool in C.
The software extracts the sent message from the SIM location at a regular interval and
processes it to control the different appliances connected within the interface. We have
made use of the Nokia F-Bus protocol to communicate with the mobile phone set. Most
Nokia phones have F-Bus and M-Bus connections that can be used to connect a phone to
a PC or in our case a microcontroller. The connection can be used for controlling just
about all functions of the phone, as well as uploading new firmware etc. This bus will
allow us to send and receive SMS messages.
The very popular Nokia 3310/3315 has the F Bus and M Bus connection under the
battery holder. This is a bit of a pain to get to and requires a special cable to make the
connection.
Conclusion
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 technical knowledge that homeowners
have.