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HOME AUTOMATION USING MOBILE PHONES

PRESENTED BYGIRISH HARMUKHNEERAJ YADAVM.Sc. IVrth SEM.

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CONTENTS1. INTRODUCTION2. COMPONENTS USED3. WORKING OF PROJECT4. DTMF KEYPAD LAYOUT5. DTMF DECODER IC WORKING6. MICROCONTROLLER7. SOFTWARE USED8. RELAY DRIVER IC WORKING9. APPLICATION 10.ADVANTAGES11.DISADVANTAGES12.FUTURE SCOPE13.PROJECT COST14.CONCLUSION15.REFERENCES

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INTRODUCTION We operate our home appliances like lights,fan,water

pump,tv etc. from our office,collage or any other remote place. So if we forget to switch off the lights or other appliances while going out, it helps to turn off the appliances with our cell phone.

cell phone works as remote control for home appliances. There is a mobile phone connected in the circuit through headphone which receives the ‘Dual Tone Multiple frequency’ (DTMF) tone by headphone and proceeds it to the circuit attach with it. The system also gives you voice acknowledgement of the applicable status.

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COMPONENT USED-1. TRANSFORMER2. VOLTAGE REGULATOR ( 7805,7812 )3. RESISTORS ( 100 KΩ, 300KΩ,470Ω )4. CAPACITOR (22PF,104PF )5. CRYSTAL OSCILLATOR (3.57 MHZ, 12 MHZ ) 6. DTMF DECODER IC ( M 8870 ) 7. MICROCONTROLLER ( AVR ATMEGA8 )8. RELAY DRIVER (ULN 2803)9. RELAYS 12V DC10. LEDS11. MOBILE PHONES

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HOME AUTOMATION USING MOBILE PHONE

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BLOCK DIAGRAM-

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WORKING The first step is to call the receiver phone.

Next we press the required digit on keypad of sender

phone to give an input.

DTMF decoder converts the dual tone . frequency into a digital signal 4 bit binary.

Output from decoder becomes the input to the microcontroller

Processing of the digital signal takes place and an input is generated for relay driving IC- ULN 2803.

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Each appliance has a different relay unit controlling its ON,OFF operation.

In this project we control 2 appliances as; (1) Key 2 > appliance 1 ON Key 5 > appliance 1 OFF

(2) Key 3 > appliance 2 ON Key 6 > appliance 2 OFF

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CIRCUIT DIAGRAM

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DTMF KEYPAD LAYOUT A DTMF keypad (generator or encoder generates a sinusoidal tone which is mixture of the row and column frequencies.

The row and column frequencies corresponding to a DTMF keypad have been indicated in the above figure.

DTMF tones are able to represent one of the 16 different states or symbols on the keypad 1209 Hz 1336 Hz 1477 Hz

697 Hz 1 2 3770 Hz 4 5 6852 Hz 7 8 9941 Hz * 0 #

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DTMF Decoder IC (MT8870) On pressing any key say key 1, combination of frequencies 1209 and 697 Hz will be generated by keypad which is fed to IC through sound converter which in turn produce the output 0001 (Q1, Q2, Q3, Q4). Following table shows output of remaining keys.

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AVR ATMEGA8 MICRO-CONTROLLER ATmega8 is a 8-bit microcontroller based on the AVR RISC architectureMEMORY

SEGMENTS 8K Bytes of Flash program memory.

512 Bytes non volatile EEPROM (Electrically Erasable Programmable Read Only Memory).

1K Byte Internal RAM (Random Access Memory).

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PIN DIAGRAM OF AVR ATMEGA8 MICROCONTROLLER

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PORTS Three ports i.e. PortB, PortC, PortD Three registers associated with every port DDRx – Data Direction Register PINx – Port input PORTx- Port output

‘x’ is subscript and could be either of PORT B, C, D

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Port B (PB7..PB0) Port B is an 8-bit bi-directional I/O port.

Can be used either as a input port or as output port (direction must be specified in programming).Port C (PC6..PC0) Port C is an 7-bit bi-directional I/O port

Can be used either as a input port or as output port (direction must be specified in programming).

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Port D (PD7..PD0) Port D is an 8-bit bi-directional I/O port

Can be used either as a input port or as output port ( direction must be specified in coding).

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REGISTER DESCRIPTION OF I/O PORTS

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Examples :

To make all pins of port A as input pins : DDRA = 0b00000000;

To make all pins of port A as output pins DDRA = 0b11111111;

To make lower nibble of port B as output and higher nibble as input DDRB = 0b00001111

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TOOLS : Compiler : WinAVR/AVR Studio/CodeVision AVR. The programmer hardware.

Bread board, wires, power supply, crystal, etc.

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EMBEDED C : Embedded C is a nothing but a subset of c language is compatible with certain microcontrollers.

some features are added some header files like <avr/io.h>,<until/delay.h> scanf() and printf() are removed as the inputs are scanned from the sensors and output are given to the ports. control structure remain the same like if statement ,for loop, do while etc.

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Structure of a c program for an embedded system :*//headers #include<avr/io.h //header file for AVR i/o #include<until/delay.h> //header file for delay *// main program * int main() * while(1) code………..] *return(0);

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SOFTWARE USEDWe use the Embedded C for programming

#include<avr/io.h>void main()DDRD = 0xff;DDRB = 0xff;DDRC = 0x00;int _dtmf;while(1)_dtmf = PINC & 0b0001111;if(_dtmf == 2)PORTB = 0b00000010;if(_dtmf == 5)

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PORTB = 0b00000000;if(_dtmf == 1)PORTB = 0b00000010;PORTD = 0b00000010;if(_dtmf == 4)PORTB = 0b00000000;PORTD = 0b00000000;if(_dtmf == 3)PORTD = 0b00000010;if(_dtmf == 6)PORTD = 0b00000000;

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RELAY DRIVER (ULN 2803) ULN2803 is a High voltage, high current Transistor Array IC used especially with Microcontrollers where we need to drive high power loads. Thic IC consists of a eight NPN Darlington connected transistors with common Clamp diodes for switching the loads connected to the output. This IC is widely used to drive high loads such Lamps, relays, motors etc. It is usually rated at 50v/500mA.

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RELAYA RELAY is an electrically operated switch. Relay are used where necessary to control a circuit by a lower power signal or where several circuits must be controlled by one signal.

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HOME AUTOMATION USING MOBILE PHONES

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APPLICATION This is system can be used in industrial application.

This system can be employed in house, where people often forget to switch off electrical appliances.

This system can be used to control AC’S to set the room temperature when we are outside.

We can extend this circuit to control many electrical devices with some modification using 4×16 Decoder IC.

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ADVANTAGESplace round the globe. We can control appliances from any place

round the globe. Quick response is achieved. Construction is easy. Easy to maintain and repair Design is efficient and low cost. Power consumption is low. Controlling electricity devices wirelessly. Saves electricity (when we forget to switch off and go out ).

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DISADVANTAGES This system is not capable of displaying the feedback status of the devices being operated.

This system needs a cell phone to be placed in circuit.

Any one who knows the phone number and code can control our electrical appliances.

Number of electrical appliances that can be controlled by the circuit is limited.

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FUTURE SCOPE In this project in future we can add a multimedia camera to see what is going inside the home by sitting office or somewhere.

This project can be further enhanced to the high voltage A.C. Appliances by changing the rating of the Relay.

We can also add some security features in the circuit. one of the way is password protection. through this only selected people can access this control over the home appliances.

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PROJECT COST-1. TRANSFORMER = 35 rs2. VOLTAGE REGULATOR ( 7805,7812 ) = 10 rs3. RESISTORS ( 100 KΩ, 300KΩ,470Ω ) = 5 rs

4. CAPACITOR (22PF,104PF ) = 15 rs5. CRYSTAL OSCILLATOR (3.57 MHZ, 12 MHZ ) = 12 rs6. DTMF DECODER IC ( M 8870 ) = 8 rs7. MICROCONTROLLER ( AVR ATMEGA8 ) = 75 rs8. RELAY DRIVER (ULN 2803) = 12 rs9. RELAYS 12V DC = 26 rs10. LEDS = 3 rs

= 201 rs

COST OF USED COMPONENT

INCLUDE OTHER COMPONENTS THE TOTAL PROJECT COST IS APPROX 500 RS.

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CONCLUSION Using highly advanced IC’S and with the help of growing technology the project has been successfully implemented.

Finally we conclude that “HOME AUTOMATION USING MOBILE PHONE ’’ DTMF based technology is an emerging field and there is a hug scope for research and development.

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REFERENCES www.kanda.com › .. Atmel AVR 89S and PLD › AVR Microcontrollers

Www.dnatechindia.com/interfacing DTMF-8870.aspx

www.discovercircuits.com/D/dtmf.htm

www.atmel.com/devices/ATMEGA8.aspx

www.roboedutechindia.com

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THANK

YOU