4. A B R I E F D E S C R I P T I O N
B L O C K D I A G R A M
M E T H O D O L O G Y
K E Y O B J E C T I V E S
U S E S O F T H E P R O J E C T
5. A BRIEF DESCRIPTION
• My project is Message Electronic Display
Board which displays the messages received as
SMS.
• Public can send flash information from Mobiles
or PCs to displays for instant viewing.
• Displays are designed to quickly display large
amounts of information in the liquid crystal
display.
6. • Based on the principle of serial communication in collaboration
with embedded systems.
• This project is an implementation to the idea of the wireless
communication between a mobile phone and a microcontroller.
• It uses:
a) A message display, which will be used as the digital notice
board
b) A GSM modem, which is the latest technology used for
communication between the mobile and the embedded devices.
c) Microcontroller, ATMEL AT89S52
8. METHODOLOGY
User wants to display a message
User sends the message in his mobile
defining the messages and then the
password of the system to the number of
the subscriber identity module (SIM) which
is inserted in the display system MODEM.
9. The GSM modem receives the SMS. The
AT commands are serially transferred to
the modem through MAX232.
The microcontroller will read the
message from serial headphone and
verify for the password, if the password
is correct then it will start displaying the
messages in the display system
10. KEY OBJECTIVES
1. Programming of the mobile phone with AT (Attention)
command sequence
2. Interfacing the programming chip with the personal
computer
3. Interfacing the programmable chip with the electronic board
display
4. Interfacing of the mobile phone with the programmable chip
5. Sending messages from the remote phone to the electronic
board
11.
12. GSM
• GSM (Global System for Mobile communications:
originally from GROUPE Spécial Mobile) is the most
popular standard for mobile phones in the world.
• GSM differs from its predecessors in that both signaling
and speech channels are digital, and thus is considered a
second generation (2G) mobile phone system.
• Most 2G GSM networks operate in the 900 MHz or 1800
MHz bands.
• The modulation used in GSM is Gaussian minimum-shift
keying (GMSK), a kind of continuous-phase frequency
shift keying.
13. SIM
• The SIM is a detachable smart
card containing the user's subscription
information and phone book.
• It is an integrated circuit that securely
stores the International Mobile
Subscriber Identity (IMSI) and the
related key used to identify and
authenticate subscriber on mobile
telephony devices.
14. PROGRAMMER
• Keil µVision3 adds many new features to the Editor
like Text Templates, Quick Function Navigation, and
Syntax Coloring with brace high lighting
Configuration Wizard for dialog based startup and
debugger setup. µVision3 is fully compatible to
µVision2 and can be used in parallel with µVision2
• µVision3 is an IDE (Integrated Development
Environment) that helps you write, compile, and
debug embedded programs.
15. M A I N C I R C U I T B O A R D
T E C H N I C A L S P E C I F I C A T I O N S
19. APPLICATION OF THE PROJECT
• Banks
• Effective traffic control
• Advertisements
• Education sector
• Information exchange
• Stock exchanges
20. A D V A N T A G E S
• This prototype has facilities
to be integrated with a
display board thus making it
truly mobile.
• The SMS is deleted from the
phone each time it is read,
thus making room for the
next SMS.
• The systems need not be
reprogrammed to display
new messages because it is
wireless.
• Communications between
the subscriber and the base
station can be encrypted.
L I M I T A T I O N S
• Currently the main work that
has been done on this
proposed system is through
serial port to the computer
but not wireless.
• The major constraints
incorporated are the use of
‘*’ as the termination
character of the SMS and the
display of one SMS as at a
time.
• These limitations can be
removed by the use of
higher end microcontrollers
and extended RAM.
