My Fianl Synophsis

7/31/2019 My Fianl Synophsis

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A

SYNOPSIS

ON

CELL PHONE OPERATED DEVICE SWITCHING

SUBMITTED IN PARTIAL FULLFILLMENT OF THE REQUIREMENT

FOR THE AWARD OF THE DEGREE

OF

BACHELOR OF TECHNOLOGY

IN

ELECTRONICS & COMMUNICATION ENGINEERING

Submitted By:-

Abhishek Goyal (08EMTEC003)

Ashish Gupta (08EMTEC016)

Devvrat Agarwal (08EMTEC029)

Mayank Kumar (08EMTEC062)

Department Of Electronics And Communication Engineering

RAJATHAN TECHNICAL UNIVERSITY,KOTA


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CELL PHONE OPERATED DEVICE SWITCHING

Conventionally, wireless-controlled devices use RF circuits, which have the

drawbacks of limited working range, limited frequency range and limited control.

Use of a mobile phone for device control can overcome these limitations. Itprovides the advantages of robust control, working range as large as the coverage

area of the service provider, no interference with other controllers and up to

twelve controls.

Project OverviewIn this project, the appliances in an office or home are controlled by .a mobile

phone that makes a call to the mobile phone attached to the receiver section. Inthe- course of a call, if any button is pressed, a tone corresponding to the button

pressed is heard at the other end of the call. This tone is called Dual- Tone

Multiple- Frequency (DTMF) tone. The receiver section perceives this DTMF

tone with the help of the phone stacked in the receiver section.

The received tone is processed by the AT89S51 microcontroller with the help of

DTMF decoder MT8870. The decoder decodes the DTMF tone into its equivalent

binary number and this binary number is sent to the microcontroller. The

microcontroller is programmed to take a decision for any given input and outputsits decision to the relay driver in order to drive the relays to switch ON or OFFthe corresponding device.

The mobile that make call to the mobile phone stacked in the receiver section actsas a remote. So this simple project doesnt require the construction of receiver

and transmitter units.

DTMF signaling is used for telephone signaling over the line in the voice-

frequency band to the call switching centre. The version of DTMF used fortelephone tone dialing is known as Touch-Tone. DTMF assigns a specific

frequency (consisting of two separate tones) to each key so that it can easily be

identified by the electronic circuit. The signal generated by the DTMF encoder is

a direct algebraic summation, in real time, of the amplitudes of two sine (cosine)

waves of different frequencies, i.e., pressing 5 will send a tone made by adding

1336 Hz and 770 Hz to the other end of the line. The tones and assignments in a

DTMF system are shown in Table I.


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Circuit Diagram of Cell Phone Operated Device switching

CIRCUIT DIAGRAM FOR THE RELAY SECTION


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Table I

Tones and assignments

In a DTMF system

Fig.1 Block Diagram of cell phone operated device switching

Frequencies 1209Hz 1336Hz 1477Hz 1633Hz

697Hz 1 2 3 A

770Hz 4 5 6 B

852Hz 7 8 9 C

941Hz * 0 # D

MOBILE

PHONE

DTMF

DECODER

MICROCONTROLLER RELAY DRIVER FIVE RELAYNETWORK

MOBILE

USED AS

REMOTE


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Circuit Description

Fig.1 shows the block diagram of the microcontroller based mobile phone

operated device switching. The important components of this circuit aremicrocontroller, DTMF decoder and relay driver.

An MT8870 series DTMF decoder used here. All types of the MT8870 series use

digital counting techniques to detect and decode all the 16 DTMF tone pairs into

a 4-bit code output. The built-in dial tone rejection circuit eliminates the need forpre-filtering. When the input signal given at pin 2 (IN-) in single-ended input

configuration is recognized to be effective, the correct 4-bit decode signal of the

DTMF tone is transferred to Q1 (pin 11) through Q4 (pin 14) outputs.

Table II shows the DTMF data output table of MT8870. Q1 through Q4 outputs

of the DTMF decoder (U1) are connected to port pins P1.0 through P1.3 ofAT89C52 microcontroller (U3) after inversion by N1 through N4, respectively.

The AT89C52 is a low power, 8-bit, CMOS microcontroller. It provides the

following features: 8kB of in-system ROM, 256 bytes of RAM and 32 general

purpose input/output lines.

ULN2003 is used as relay driver. Output from the microcontroller from port pinsP0.0 to P0.4 are fed as the five inputs to the ULN2003. ULN2003 will energize

the appropriate relay upon getting the corresponding input from the

microcontroller.


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COMPONENT LIST

S.No. COMPONENT ID COMPONENT LIST QTY.

IC

1 U2 L293D WITH 16 PIN BASE 0

2 U3 AT89S51 WITH 40 PIN

BASE

1

3 U4 ULN2803 WITH 18 PIN

BASE

1

4 U5 MT8870 WITH 18 PIN BASE 1

5 U6 74LS04 WITH 14 PIN BASE 16 ZERO PCB LM324 WITH 14 PIN BASE 0

7 Q1 IC 7805 1

8 LCD 1

RESISTANCE

8 R8,R6,R5,R4,R3 470 15

9 R11,R12 1K OHM 5

10 R2 10K OHM 511 R9,R10 100K OHM 3

12 R7 330k OHM 2

13 RW1 10K OHM PULLUP

RESISTANCE 9 PIN

1

14 VR1 1K OHM POTENTIOMETER 1

LED

15 LD2,LD3,LD4,LD5,LD6,LD6,LD7,LD8 RED LED TRANSPARETCOVERING

15

CAPACITOR

16 C15,C16 22 f CERAMIC 3

17 C11,C12 33 f CERAMIC 3

18 C14,C13 104 CERAMIC 2

CRYSTAL OCILLATOR

19 Y1 12 MHz 120 Y2 3.57 MHz 1


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SWITCH

21 SW1 RESET MICRO SWITCH 4

PIN

2

CONNECTORS

22 RN2,CN3,CN4,CN5,CN7,CN8,C9,C10 TWO PIN CONNECTOR 5

23 CN6 FOUR PIN CONNECTOR 3

24 J3 MALE BUG STRIP (50) PIN 1

25 DS1 FEMALE BUG STRIP (50)

PIN

1

OTHERS

26 K1,K2 RELAY 12V OPERATING 2

27 DIODE IN4007 DIODE 2

28 HEADPHONE 2.5MM/3.5MM JACK HEAD

PHONE

1

29 ZERO PCB IR SENSOR PAIR 3MM 0

30 ZERO PCB 22K POTENTIOMETER

SMALL SIZE

0

31 SOLDERING PURPOSE SOLDER WIRE(BHARTI

INDUSTRY)

1

32 DC GEAR MOTOR (RPM) 0

33 D R = DTMF ROBOT FREEWHEEL SHAFT 0

34 D D = DTMF DEVICE WHEEL 0

35 M T = METRO TRAIN CUTTER 1

36 P F = PATH FINDER SOLDER IRON 1

37 L F = LINE FOLLOWER CHESIS 0

38 S S = SECURITY SYSTEM NOSE PLIER 1

39 ELECTRIC BLACK TAPE 1

40 9 V BATTERY WITH

CONNECTOR

1

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My Fianl Synophsis