dtmf logic basics and circuitary ppt

8/13/2019 DTMF LOgic basics and circuitary ppt.

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In the present world of wireless technology every thing is

going to be digital and wireless, and the cell phone is the key player

in wireless technology today. And today technology made the

possessing of a mobile, considered as a basic commodity.

And the trends in wireless technology changing day-by-day

and today the working is going on how to develop remote devices

with out the presence of man and to reduce to the time factor and

labor, and our project belongs to that race and by using it we can

control any electronic devices through a touch cell phone, with oneCall.



The main objective of this DTMF BASEDREMOTE CONTROL SYSTEM project is to develop an

embedded system which can control remote appliances

remotely by using telephone line. In this embedded

System Project we are going to develop an embedded

system which will control the remote appliances with thetelephone lines. We can control more than 10 electrical

Appliances.

First of all the telephone lines of data are

transmitting through the transmitter by the encoder, it

will encode the data without noise, and then the data will

be received at the receiver, so that the receiving data is

decode as original data of telephone line by the decoder,

then the original data is stored in microcontroller and it

will control the all the electrical system.



The project works on the principle of DTMF tone command soreceived from any phone to remotely switch any electrical load such as

agricultural pump, domestic and industrial loads etc. In industries, the

loads are spread over a large area and thus, operating these loads is a

very tiresome and difficult task. In agricultural fields also, pumps and

other loads are connected over a large area and hence it is difficult for the

farmer to operate all the loads and similarly for house hold loads.

Keeping these problems in mind, the proposed system has

been designed which uses DTMF technology to control the loads

remotely. A cell phone is interfaced to a DTMF decoder in the systemfrom its audio output socket for receiving tone commands.



The receiving cell phone codes are converted into digital

commands by using a DTMF Decoder which will identify the frequency

of the key and convert that frequency to its equivalent digital code

which is then fed to a microcontroller (8051 family).

As per the commands sent from the sender’s mobile, the

microcontroller will send signals through a buffer to actuate the

respective loads by turning the relays ON/OFF. These relays are

actuated by a relay driver IC interfaced to the microcontroller. Further

this project can be enhanced by using a GSM modem, where the loads

can be controlled by sending an SMS. This will eliminate the need of

answering the call for the system to work.

dtmf logic basics and circuitary ppt

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