REMOTE CONTROL REMOTE CONTROL USING DTMFUSING DTMF

Project guide :- Reena Project guide :- Reena kumbharekumbhare

Inhouse projectInhouse project

Pramod Avula Pramod Avula Roll no :- 4Roll no :- 4

D Shreenivasrao D D Shreenivasrao D Roll no :- Roll no :- 99

Sitaraman V Iyer Sitaraman V Iyer Roll no :- 33Roll no :- 33 Vivek Metkar Roll no :- Vivek Metkar Roll no :-

4343

Aim of the project:-Aim of the project:-

To Perform Remote To Perform Remote Switching of appliances Switching of appliances & other industrial & other industrial applications using applications using DTMF.DTMF.

DTMFDTMF (Dual Tone (Dual Tone Multi Frequency)Multi Frequency)

Was developed at Bell labsWas developed at Bell labs To allow dialing signals over nonwire To allow dialing signals over nonwire

links links Also Known as Touch tone Also Known as Touch tone Are also sometimes used in Are also sometimes used in caller IDcaller ID

systems systems Developed in the 1950’s,it became Developed in the 1950’s,it became

obsolete a decade after it was obsolete a decade after it was institutedinstituted

Initial Telephone Initial Telephone exchangeexchange

DTMF keypad DTMF keypad frequencies frequencies

f(t) = Asin(2*П*fa*t) + f(t) = Asin(2*П*fa*t) + Bsin(2*П*fb*t) Bsin(2*П*fb*t)

DTMF Waveforms DTMF Waveforms

Block diagram & Flow Block diagram & Flow chartchart

Flow Chart

MT8870MT8870

Basic Working : Receives DTMF Basic Working : Receives DTMF signal and converts to respective signal and converts to respective BCDBCD

FeaturesFeatures

Integrates both band split filter and Integrates both band split filter and decoderdecoder

uses a digital counting technique uses a digital counting technique provides a differential input provides a differential input

operational amplifier as well as a operational amplifier as well as a bias source bias source

Hardware components & Hardware components & Software tools used.Software tools used.

AT89C51 AT89C51 MicrocontrollerMicrocontroller

IC MT8870 DTMF IC MT8870 DTMF DecoderDecoder

Component Component DescriptionDescription

APR6008 Voice ICAPR6008 Voice IC LM386 Audio LM386 Audio

Power AmplifierPower Amplifier

HA 17358 HA 17358 Operational Operational AmplifierAmplifier

L78XX Voltage L78XX Voltage RegulatorRegulator

BC547 TransistorBC547 Transistor Keil programming Keil programming

kitkit

Work done in Sem VIIWork done in Sem VII

Studied DTMF Studied DTMF Worked on Literature surveyWorked on Literature survey Have the final list of Hardware Have the final list of Hardware

ComponentsComponents

Future Course of ActionFuture Course of Action

In our project, basically 6 modules are In our project, basically 6 modules are required to be designed.required to be designed.

Power SupplyPower SupplyMicrocontroller BoardMicrocontroller BoardRing Detector CircuitRing Detector CircuitDTMF Decoder CircuitDTMF Decoder CircuitVoice IC CircuitVoice IC CircuitRelay Board Relay Board

Final look of projectFinal look of project

List of ReferenceList of Reference Microprocessor Microprocessor

Architecture, Architecture, programming and programming and applications -applications -GaonkarGaonkar

The 8051 Microcontroller-The 8051 Microcontroller-AyalaAyala

Op-Amps and linear Op-Amps and linear integrated circuits -integrated circuits -GayakwadGayakwad

Electronic Communication Electronic Communication Systems-Systems-Wayne TomassiWayne Tomassi

http://.http://.electronics.howstuffworks.electronics.howstuffworks.comcom//

www.google.comwww.google.com www.datasheetarchive.cowww.datasheetarchive.co

mm www.atmel.comwww.atmel.com http://en.wikipedia.org/http://en.wikipedia.org/

wikiwiki http://www.tkk.fi/Misc/http://www.tkk.fi/Misc/

Electronics/circuits/Electronics/circuits/telephone_ringer.htmltelephone_ringer.html