SRI VENKATESWARA ENGINEERING COLLEGE(Sponsored by exhibition society AfflIiated by JNTU Hyderabad)

Under the guidance of B.Swetha M.tech

Presented by:

K. Navya - 449S. Harikrishna - 421P. Ganesh - 418N .Rajiv - 458

GSM Based Wireless Notice Board

Main project report on

CONTENTS Aim of the project

Introduction

Block Diagram

GSM Modem

AT commands

Max 232

LED Display

Features of LPC 2148

Flow Chart

Advantages

Disadvantages

Conclusion

Future scope

AIM OF THE PROJECT

Notice Board is primary thing in any institution or organization or public utility places like bus stations, railway stations and parks. But sticking various notices day-to-day is a difficult process.

INTRODUCTION

It presents an SMS based notice board incorporating the widely used GSM to facilitate the communication of displaying message on notice board via user’s mobile phone.

SIM900 GSM modem with a SIM card is interfaced to the ports of the microcontroller with the help of AT commands.

SIM900 is duly interfaced through a level shifter IC MAX232 to the microcontroller. The messaged is thus fetched into the microcontroller.

It is further displayed on an electronic notice board which equipped with LED display interfaced to microprocessor powered by a regulated power supply from mains supply of 230 volts ac.

BLOCK DIAGRAM

lpc2148

GSM Modem

GSM modem is the Data Communicating Equipment which is connected to terminal equipment for data transmission and reception.

GSM stands for Global System for Mobile Communication

SIM stands for Subscriber identity Module

GSM modem is controlled using AT commands

AT stands for Attention

Ex- AT, AT+CMGR, AT+CMGS, AT+CMGD etc.

SCHEMATIC DIAGRAM

AT Commands & Corresponding Operation

AT Commands Description

AT To check if Modem is connected properly

ATE0 To turn echo off

ATE1 To turn echo on

AT+CMGF Set operating Mode

AT Commands & Corresponding Operation

AT Commands DescriptionAT+CMGD= <index>, <delflag>

To delete a message

AT+CMGR= <index> To read message from an index

AT+CMGS= “contact no.” , TP-type address

To send message to specified contact no.

MAX 232

MAX 232 IC

MAX 232 that converts signals from an RS-232 serial port to signals suitable for use in TTL compatible digital logic circuits.

The MAX 232 is a dual driver/receiver and typically converts the RX, TX CTS and RTS signals.

It changes a TTL Logic 0 to between +3 and +15 V, and changes TTL logic 1 to between -3 to -15V, and vice versa for converting from RS232 to TTL.

User wants to display a message in the led board

User sends the message from his mobile defining the message in the code format and then to the number of the subscriber identity module (SIM) which is inserted in the display system MODEM.

LED DISPLAY

ARM7

ARM7

ARM: Advanced RISC Machine Founded in1990, owned by Acorn, Apple and VLSI Most widely used 32-bit instruction set architecture Suitable for low power devices Used extensively in consumer electronics, PDA (Personal

Digital Assistant), mobile phones, computer peripherals (hard drives & routers), music players, game consoles, calculators, etc.,

FEATURES OF LPC 2148

8 kb to 40 kb of on-chip static RAM and 32 kB to 512 kB of on-

chip flash memory.

128-bit wide interface/accelerator enables high-speed 60 MHz

operation

Operating voltage range of 3.0 V to 3.6 V

Single 10-bit D/A converter provides variable analog output.

Two 32-bit timers/external event counters

FLOW CHART

ADVANTAGES

Using GSM mobile we can send message to any distant locations , from any part of the

World

As it's a GSM wireless transmission system it has very less errors and needs less

maintenance

Prevents unauthorized access of notice board (password)

Multiple Users are authorized to update notices on the electronic notice board

No printing and photocopying costs. Thus saves time, Energy and finally environment

DISADVANTAGES

When there is network problem GSM doesn’t work

APPLICATIONS

Educational institutions & organizations

Managing traffic

Advertisement Conference hall

Bus/Railway station

Any Public utility places

CONCLUSION

We can use this Project in college Notice Board, a Professor can send message

for the immediate gathering of students at department.

It can be used on Highways for traffic control, like traffic on one side of the

road may be blocked in view of VVIP movement or jam ahead

FUTURE SCOPE

Temperature and time (RTC ) display during periods when no

messages are to be displayed

GSM based home security system, GSM based robot control, GSM

based DC motor controller, GSM based stepper motor controller,

GSM based voting machine control et