Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Dtmf cntrl of appliance using mobile phones

Status
Not open for further replies.
S

snehanair

Newbie level 4
Newbie level 4
Joined
Jan 8, 2011
Messages
5
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,281
Activity points
1,314
I am about to do a proj regarding dtmf control of home appliance using mobile phone..i have many doubts..like where to fix the appliance..and which key turns on/off which appliance....can any1 please help me!!!!
 

snehanair said:
I am about to do a proj regarding dtmf control of home appliance using mobile phone..i have many doubts..like where to fix the appliance..and which key turns on/off which appliance....can any1 please help me!!!!
Click to expand...



the main ic chip is 74154 ic.
the pins 2 to 11 are the output pins of the circuit..

when you press key 1 of cell phone the corresponding dtmf toggles the logic level of pin 2 of 54154..
key 2-pin3
key3-pin4
.
.
.
key9-pin10

key0-pin 11(this key 0 has to be pressed if u want the circuit to answer the call..if u leave it unpressed then the circuit remains unaffected.
ask if u have any doubts)
 
thank u sir....
sir i have another doubt where to connect the appliance?is it in pins of CD4049?then the specification for relay9 is not provided...The circuit u provided seems to be that of controlling appliance using telephone...i need that of a mobile phone..
 

    V

    Points: 2
    Helpful Answer Positive Rating
at the place of transmitter u can also use mobile phone to generate the dtmf signal. or
use two mobile phone. first is connected to receiver circuit and make automatic answer enable. when you call by second mobile phone to first , the call will received automatically. then press any key (0-9), you will get binary o/p.
at op of ic kt3170 you can use decoder ic 7442 to obtain decoded o/p from 0-9.
then use cd4013 as toggle circuit.
 

Attachments

  • dtmf remote.gif
    dtmf remote.gif
    30 KB · Views: 177
all connections are similiar to ic 5b...
outputs of not gates goes to clock of d flipflop and output of flipflop Q is connected to transistor as a switch then connect the relay to control heavier loads.
this circuit need one of the cheapest phone to be connected...connect the head set...remove the ear phones and connect it to the signal input pin of dtmf decodeer
hope it helps
take care
 
thank u sooo much sir!!!!:grin::lol:
 

you are welcome..thats why we are here for...all we do in this site is help others by sharing our knowledge..
here now there is no security..
any one who wisheshes to call can conrtol your circuit..
so it is better you connect the output of dtmf decoder to micro controller and then connect the microcontroller to the next stage...
i do not know programming..if you know u can put some key combinations as password to drive next stage...if wrong password is entered the circuit will be inaccessable...
all the best
 

sure sir....will try and if posiible will include anythng i get in extra...thanks alot:lol::lol:....
 

Can anyone please list the exact equipments needed for this circuit? it will be helpfull for me as i am also trying to make the same thing.

Thank You
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top