Presented By:

K.SHASHIDHAR (11UE1A0482) N.SANDYA RANI (11UE1A0476)CH.SAMPATH (11UE1A0472) B.THARUN REDDY (11UE1A04A0)

TRINITY COLLEGE OF ENGINEERING AND TECHNOLOGYKARIMNAGAR

DTMF BASED APPLIANCES CONTROL SYSTEM FOR

RURAL AND AGRICULTURAL APPLICATIONS

To design a project “DTMF BASED APPLIANCES CONTROL

SYSTEM FOR RURAL AND AGRICULTURAL APPLICATIONS” to

control Electrical devices using mobile phone.

AIM OF THE PROJECT

As technology advanced man was able to control everything from one place.

Now-a-Days Automation is playing an important role in each and Every field such as Industrial, Home, Rural and Agricultural Areas.

Usually we used to control the industrial equipments by manual operation, which increases the human effort and maintenance cost.

In order to overcome this problem, the system is designed to control devices at remote place.

To control the devices from remote place we are using a DTMF(Dual Tone Multi Frequency) technique.

INTRODUCTION

HARDWARE:

ATMEGA8 Microcontroller

Regulated Power Supply

DTMF Decoder Board

Voltage Regulator

DC Motor

Bulb

Mobile Phone

Relay

SOFTWARE:

AVR Studio5

Proteus7.7

PROGISP

REQUIREMENTS

Power Supply

Mobile Keypad

ATMEGA8

Relay Unit

BulbDc

motor

ControllingMobile

DTMFDecoder

BLOCK DIAGRAM

When we press keys in our cell Phone when call is in progress, the other person will hear some tones with respect to keys pressed. These tones are based on the DTMF technology.

And Just connect your cell phone headset (headphone) jack to the mobile phone.

The tones produced by the mobile keypad which have some frequency.

DTMF Decoder converts the desired frequency into analog signals and gives to ATMEGA8 microcontroller.

The microcontroller is used for switching the load equipment according to the frequency received by the DTMF receiver by using a combination of Relays.

WORKING

The input to the circuit is applied from the

regulated power supply, i.e. 240V A.C. is converted into

12V pure D.C. And given to the circuit.

components of power supply

Power Supply

The purpose of DTMF decoding is to detect

sinusoidal signals in the presence of noise and the

DTMF decoder IC interfaces with a microcontroller.

DTMF Decoder consists of MT8870 IC, it detects

the number or code represented by DTMF jack,

through the inspection of the two transmitted

frequencies.

DTMF Decoder

The relay takes advantage of the fact that when

electricity flows through a coil, it becomes an electromagnet.

The electromagnetic coil attracts a steel plate, which is

attached to a switch. So the switch's motion (ON and OFF) is

controlled by the current flowing to the coil, or not,

respectively.

Relay:

A microcontroller is a

single chip that contains the

processor (the CPU), non-

volatile memory for the

program (ROM or flash),

volatile memory for input and

output (RAM), a clock and an

I/O control unit.

Microcontroller is also

called as “computer on a chip”.

ATMEGA8 Microcontroller:

Pin diagram of

ATMEGA8:

ATMEGA8 Microcontroller consists of 32 general

purpose working registers. All the 32 registers are directly

connected to the Arithmetic Logic Unit (ALU), allowing two

independent registers to be accessed in one single

instruction executed in one clock cycle.

DESCRIPTION:

High-performance, Low-power consumption.

Advanced RISC Architecture.

130 Powerful Instructions – Most Single-clock Cycle Execution.

32 × 8 General Purpose Working Registers.

Programming Lock for Software Security.

Internal Calibrated RC Oscillator.

External and Internal Interrupt Sources.

RISC Architecture.

Key features of ATMEGA8:

DTMF (Dual tone multi

frequency) as the name suggests

uses a combination of two sine

wave tones to represent a key.

These tones are called row and

column frequencies as they

correspond to the layout of a

telephone keypad.

DTMF MODULE:

This system can be used in industrial applications.

This system can be employed in houses, 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 modifications.

APPLICATIONS

Quick response is achieved.

Construction is easy.

Easy to maintain and repair.

Comparatively the operation cost is less.

Design is efficient and low cost.

Power consumption is low.

We can Control electrical devices wirelessly.

It Saves electricity (when we forget to switch off and go out).

We can control appliances from any place round the globe.

ADVANTAGES

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.

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

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

DISADVANTAGES

This project can be further enhanced to be high voltage

ac applications by changing the rating of the Relay

We can control and monitor the high speed induction

motors as well as synchronous motors. This can be done in

an economical way.

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

somewhere.

FUTURE SCOPE

THANK YOU