Download DTMF Based Home Automation

Report on
“DTMF Based Home Automation”
Submitted by:
Anisha Dewan
Baldev Bhattarai
Bibek Shrestha
Grishmi Rajbhandari
Neha Karna
Kathmandu Engineering College
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Abstract
Conventionally, electrical appliances in a home are controlled via switches and the wires that
regulate the electricity to these devices. Home automation is like a common practice in our
daily lives. The procedure of home automation is implemented by making everything in the
house automatically controlled using technology to control and do the job that we would
normally do manually or in our absence. In this project we purpose a unique system for home
automation utilizing a Dual Tone Multi Frequency (DTMF) that is paired with the wireless
control over many devices in the house. This user console has a many key each
corresponding to the devices that need to be activated or deactivated. The encoder encodes
the user choice and send via transmitter. Fm receiver receives the modulated signal and
demodulates it and the user choice is determined by DTMF decoder. The acknowledgement
is provided through APR9600 IC which provides voice acknowledgements.
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Table of content
Page no.
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Abstract
Introduction
Objective
Block Diagram
Description of the Block Diagram
Advantages and application
Bibliography
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2
3
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Introduction
DTMF refers to the dual tone multi frequency signalling. This is use for telecommunication
signalling over analog telephones line in the voice frequency band between telephone
handsets and other communication devices. Generally, appliances used in our home are
controlled with the help of switches. These days you can see automation of these appliances
using many technologies. The main principle of this project (circuit) is to control the home
appliances like light, fan, and door lock using DTMF technology. DTMF encoder is present
in your mobile and decoder is CM8807. The devices connected as a home or office appliance
consume electrical power and they should be controlled as well as turn on and off as required.
Before this used to be done manually, but now it, is necessity to control the devices more
effectively and efficiently as well at any time and from anywhere. This thought can be
applicable when we have already left from the home and suddenly we remember that we
forgot to turn off the television. As it is energy consuming it has to be turn off when not in
use. We are going to develop a cellular phone based home appliance controller for
controlling electrical devices. This includes a mobile phone which is connected to the system
via head set. To activate the mobile phone unit on the system, a call is to be made and as the
call is answered; in response the user would enter a password to access the system to control
devices. As the caller presses the specific button on the keypad, it results in turning ON/OFF
specific devices switching is achieved by relays.
Figure: DTMF keypad
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The above table gives the corresponding binary values of the number keypad on mobile
handset in relation to the DTMF tones.
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Objectives
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2.
3.
4.
To use DTMF in the home automation system
To reduce unnecessary use of electricity in absence of user.
To use hand mobile phone as a remote control for home automation.
To minimize the damage and home accident caused by the malfunction of electricity
in the absence of owner or user.
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Block diagram
Transmitting
Section
Receiving Section
LCD
APR9600
Microphone
Mobile
phone
Mobile
phone
Decoder
CM8870
ATMEGA
Relay driver
ULN2003
32
Relay 1
Relay 2
Relay 3
Figure: Block Diagram of the System
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Description of the Block Diagram
The entire system, in general, can be divided into two parts: the transmitting section and the
receiving section. The transmitting section consists of a mobile phone. This mobile acts like a
remote through the wireless communication medium. The receiving section on the other
hand, consists of a mobile for communication, a decoder CM8870, a microcontroller, an IC
APR9600 for providing acknowledgment to the user, a relay driver that is again connected to
corresponding relays. The relays are attached to the corresponding appliances that are to be
controlled. In our case, these appliances include a light bulb, a fan and a door lock.
Regarding the receiving section, when the user makes a call to the home automation system,
the mobile phone automatically receives the call. The siren gives a sound signal indicating
the user to enter a 4 digit pass code. The user is given three chances to get the correct pass
code. If the user is unable to provide with the correct pass code within those chances, an
alarming alert sound signal is buzzed indicating that an intruder is messing with the system.
Now if the user gives the correct pass code, then a welcome message is displayed on the
LCD. Then another type of sound signal indicates the user to press corresponding mobile
number keys to perform the operations such as tuning on/off the light, opening/closing the
door and turning on/off the fan. As such the DTMF based Home Automation System works.
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Advantages and application
 House monitoring system: This system can be used to monitor homes in the absence
of owner. Any kind of accidents caused by fire, short circuiting of the electrical
system etc can be immediately to the reported to the user.
 Home security system: Since the user is in touch with the system, any kind of theft
can be reported, making homes secure.
 Offices/industries: This system can be used in offices, industries and other similar
areas.
 Controller of a robot: This system can also be used to drive a robot with some
modifications introduced in the system.
 Wireless system: It is wireless system. Use of GSM based mobile phone has
considerably increased the distance of communication
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Bibliography
Datasheets:
1.
2.
3.
4.
APR9600
ATmega32
ULN Relay Driver
CM8870
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