HOME AUTOMATION CONTROL

SYSTEM USING DTMF

To design a project “Home Automation Control

System Using DTMF” 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 equipment's 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

SOFTWARE: Proteus7.7 MPLAB WINPIC

Requirements

HARDWARE:

PIC18F Microcontroller

Regulated Power Supply

DTMF Decoder

Mobile Phone

Relay

BLOCK DIAGRAM

1

DTMF Decoder

Regulated Power Supply

Relay Driver ICULN2803

MICRO CONTROLLER

Relay[3]

Relay[2]

Relay[1]

Fig. Block Diagram of Home Automation Control System using DTMF

Mobile Phone

LCD Display

Call to phone which is connected to project. Receiver phone is set as auto answer mode i.e. call is received automatically after some time.

When we press keys in calling 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 PIC microcontroller.

Working

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

The working of project is when we press 1 in calling phone then the frequency is send from received phone to DTMF decoder IC and decode the incoming frequency and give it microcontroller in the binary code.

For key 1 is pressed device 1 is on and for key 2 is pressed device 1 is off, same working follow as remaining devices.

The input to the circuit is applied from the regulated

power supply, i.e. 240V A.C. is converted into 5V 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

PIN DIAGRAM OF DTMF DECODER IC

Fig. Pin Diagram of DTMF Decoder IC

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:

PIC MICROCONTROLLER:

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”.

Pin diagram of PIC18F4520

Description PIC microcontroller are developed by microchip

technology. PIC 18F4520 belongs to a 8-bit microcontroller of RISC

(Reduced Instruction Set Computing) architecture. RISC (Reduced Instruction Set Computing) as the name

says has less number of instructions.

Key Features of PIC 18F4520 High performance 8-bit microcontroller 75-powerful instructions ; most single clock cycle execution 32*8 general purpose working registers 32Kbytes flash program memory, 256 Bytes EPROM, 1536byte

internal SRAM 5 i/o port 13-channel, 10-bit ADC 36 programmable i/o lines Operating voltages 2.0-5.5V Operating speed DC-40 MHz

Relay Driver IC The eight NPN Darlington connected transistors in this family of

array are ideally suited for interfacing between low logic level digital circuitry (such as TTL, PMOS/NMOS) and the higher current/voltage requirements of lamps, relays, printer hammers or other similar loads for abroad range of computer, industrial, and consumer applications.

All devices feature open–collector outputs and freewheeling clamp diodes for transient suppression. The ULN2803 is designed to be compatible with standard TTL families while the ULN2804 is optimized for 6 to 15 volt high level MTOS or PMOS.

Fig. Pin Diagram of ULN2803 Relay Driver IC

PIN Connection OF ULN2803A

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:

LCD is used in a project

to visualize the output of the

application. We have used 16x2

LCD which indicates 16

columns and 2 rows. So, we can

write 16 characters in each line.

So, total 32 characters we can

display on 16x2 LCD.

Liquid Crystal Display:

Fig. Pin Discription

APPLICATION

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.

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 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

CONCLUSION

In these my making these the circuit as the device is connected to a corresponding circuit, its gets activated as soon as the call is made to the circuit in which mobile or equivalent GSM module is present to perform a specific operation as per the relay device is connected. In these as the keypad has12 different key, it can perform 12 distinct operation as per connected to a relay.

Thank-you