GSM Based Wireless Notice Board

Presented By:Sushant Khajuria

Rajneesh Kumar SalgotraKalyan Singh Rathore

under the guidance of Assoc. prof. A.G.Mir

Content• Block Diagram• GSM Modem• AT commands• LED Display• Circuit diagram of LED Display• ATMEGA32• Serial communication in ATMEGA32• ULN2003A• Circuit Diagram of Microcontroller• Flow Chart• Conclusion• Suggestions

BLOCK DIAGRAM

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.

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 Description

AT+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.

AT+CMGS command AT+CMGS = “+0123456789” , 145 > Welcome Now Press Ctrl+Z

AT+CMGS = “+0123456789” , 145 > Welcome Now Press Ctrl+Z

LED DOT MATRIX DISPLAY

5x7 Dot Matrix Display

• Column Cathode display

• Column Anode Display

LED Display 0 1 1 0 0

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LED Display 0 1 1 0 0

1

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1

1

1

1

1

0 1 1 0 0 0 1 0 0 0

1

0

0

1

1

1

1

1

0

0

1

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1

LED Display Bits at columns

Bits At Rows

Shift RegisterST_CP SH_CP Input Serial Data

Circuit Diagram of LED Display

Interfacing

• Microcontroller is used to interface one device from the other

Microcontroller ATmega32

Features:• Advanced RISC Architecture

• High-performance, Low-power Atmel AVR 8-bit Microcontroller • 32Kbytes of In-System Self-programmable Flash program memory • 1024Bytes EEPROM • 2Kbytes Internal SRAM • Programmable Serial USART • 32 Programmable I/O Lines• Full Duplex Serial Line as controller have independent receiver and

transmitter registers.

Serial Communication in ATmega32

• ATmega32 is Full-Duplex in serial communication• UBRR(USART Baud Rate Register)16 bit register is used for setting the

Baud rate• Out of 16 bits only 12 bits are used for setting the baud rate• Two shift registers- Transmit shift register and Receive shift register

are used for Full Duplex mode• Each shift register has its buffer• These buffers has same I/O address , which is called as UDR(USART

Data register)

Serial Communication in Atmega 32

ULN 2003A

• ULN2003 is a high voltage and current Darlington array IC

• It contains seven NPN Darlington pairs one for each input

• It is providing current amplification for LED display board

• Collector-Current rating of single darlington pair is 500mA

Circuit Diagram of Microcontroller

Flow Chart

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

• At Bus Stands, Railway Stations and Airports for the information about the timing of the Buses , trains and airplanes

• It can be used for crime prevention

Suggestion

• The System may be used to authenticate the sender with contact no. rather than authentication code, so more secure.

• Alarm can be embedded for indication of new message

• Display can be improved with larger size, more brightness