Telephone as a remote control SECURITY FEATURES! - Electronic Circuits Projects Diagrams Free

MEHLULI · 19th November 2004, 12:51 AM

:?
I am doing a final yr project of a telephone as a remote control. I am mainly concerned with the security features of it. All the sites that I have seen dont have this feature. Im planning on using a PIC16F84 to pass data from the DTMF-to-BCD converter to the 4 to 16 line Demux. Can the PIC6F84 be handy for a situation where I get BCD data to pass it on again for execution?
I need to use it for security features. I want it to FIRST aunthenticate the user before they can switch on any appliance, say by first inputting a 4-digit password, which will THEN activate the controlling circuit, allowing. after that for normal remote controlling (by pressing say digit a '1' or '2' up to '9' in DTMF mode which will be converted to BCD then to the PIC to go straight into energising the appropriate switch) to resume.

After that, pressing a '0' to disable the remote controlling system freeing the telephone line for normal use.

Can it work, and if so how?

IM STUCK! AND I AM NOT THAT GOOD IN MICROCONTROLLERS, BUT I AM A FAST LEARNER.

PLEASE HELP....

**Nigel Goodwin** · 19th November 2004, 05:43 AM

If you look at my HEX keypad tutorial I show how to make a keycode operated lock - you could simply replace the keypad reading routine with one for reading your BCD inputs.

I would also advise (as usual!) that you drop the obselete 16F84, and use it's replacement the 16F628 - better spec and cheaper!.

samcheetah · 19th November 2004, 05:56 AM

hi MEHLULI, nice to see someone from Zimbabwe. ive also been to zimbabwe and its a very beautiful country.

okay now as for your project. well, im also interested in using DTMF with PICs. the following link might be of some help to you.

http://www.brouhaha.com/~eric/pic/dtmf.html

as for learning PIC microcontrollers i would suggest that you read Nigel's tutorials http://www.winpicprog.co.uk

MEHLULI · 19th November 2004, 06:16 PM

Quote:

Originally Posted by Nigel Goodwin

If you look at my HEX keypad tutorial I show how to make a keycode operated lock - you could simply replace the keypad reading routine with one for reading your BCD inputs.

I would also advise (as usual!) that you drop the obselete 16F84, and use it's replacement the 16F628 - better spec and cheaper!.

Thanx for yo response!
Now Im curious, if I got you right, all I need is to simply replace that CODE for BCD case? If so, then what happens of the output to the Demux? I guess it needs CODE again ha!? :?

**Nigel Goodwin** · 19th November 2004, 06:28 PM

Quote:

Originally Posted by MEHLULI

Quote:

Originally Posted by Nigel Goodwin

If you look at my HEX keypad tutorial I show how to make a keycode operated lock - you could simply replace the keypad reading routine with one for reading your BCD inputs.

I would also advise (as usual!) that you drop the obselete 16F84, and use it's replacement the 16F628 - better spec and cheaper!.

Thanx for yo response!
Now Im curious, if I got you right, all I need is to simply replace that CODE for BCD case? If so, then what happens of the output to the Demux? I guess it needs CODE again ha!? :?

Yes, you would have to add your own specific output routines, but the lock code inputs and compares a 4 digit code - it's fairly easy to understand!.

MEHLULI · 19th November 2004, 06:46 PM

Quote:

Originally Posted by Nigel Goodwin

Quote:

Originally Posted by MEHLULI

Quote:

Originally Posted by Nigel Goodwin

If you look at my HEX keypad tutorial I show how to make a keycode operated lock - you could simply replace the keypad reading routine with one for reading your BCD inputs.

I would also advise (as usual!) that you drop the obselete 16F84, and use it's replacement the 16F628 - better spec and cheaper!.

Thanx for yo response!
Now Im curious, if I got you right, all I need is to simply replace that CODE for BCD case? If so, then what happens of the output to the Demux? I guess it needs CODE again ha!? :?

Yes, you would have to add your own specific output routines, but the lock code inputs and compares a 4 digit code - it's fairly easy to understand!.

:? Well, it sound easy from what you are saying but hey, Im still hazy in my thinking (No wonder you are an expert!) So, I write code for aunthentification, which I seem to understand (though I dont know how I will go about it), then what about the other digits that do the switching and the '0' that terminates the sytem? All this is ideas coming in my head but which are skeleton. Can you help me add flesh here, please!

**Nigel Goodwin** · 19th November 2004, 07:10 PM

Quote:

Originally Posted by MEHLULI

:? Well, it sound easy from what you are saying but hey, Im still hazy in my thinking (No wonder you are an expert!) So, I write code for aunthentification, which I seem to understand (though I dont know how I will go about it), then what about the other digits that do the switching and the '0' that terminates the sytem? All this is ideas coming in my head but which are skeleton. Can you help me add flesh here, please!

All my tutorial example does is wait for four keypresses, these are displayed on an LCD as they are pressed, and stored in four variables. Once the fourth one has been pressed it goes to a verification routine, this simply compares the four registers against the values set for the access code. If the code is correct is display so on the LCD, if it's incorrect it tells you that instead.

MEHLULI · 19th November 2004, 07:38 PM

All my tutorial example does is wait for four keypresses, these are displayed on an LCD as they are pressed, and stored in four variables. Once the fourth one has been pressed it goes to a verification routine, this simply compares the four registers against the values set for the access code. If the code is correct is display so on the LCD, if it's incorrect it tells you that instead.[/quote]

Thank you for that 8) So, even though I can not have an LCD can I still go thru that routine as it get it from the register in the PIC? I hope so. Now the real unclear part is that after the verification has passed, to getting in the controlling system, how is the input intepreted by the PIC? Can it be that easy to say wen code verified, then wen '1' is pressed can the signal goes straight as if we had no pic to activate appliance connected through that DTMF signal?

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19th November 2004, 12:51 AM	(permalink)
MEHLULI	Telephone as a remote control SECURITY FEATURES! :? I am doing a final yr project of a telephone as a remote control. I am mainly concerned with the security features of it. All the sites that I have seen dont have this feature. Im planning on using a PIC16F84 to pass data from the DTMF-to-BCD converter to the 4 to 16 line Demux. Can the PIC6F84 be handy for a situation where I get BCD data to pass it on again for execution? I need to use it for security features. I want it to FIRST aunthenticate the user before they can switch on any appliance, say by first inputting a 4-digit password, which will THEN activate the controlling circuit, allowing. after that for normal remote controlling (by pressing say digit a '1' or '2' up to '9' in DTMF mode which will be converted to BCD then to the PIC to go straight into energising the appropriate switch) to resume. After that, pressing a '0' to disable the remote controlling system freeing the telephone line for normal use. Can it work, and if so how? IM STUCK! AND I AM NOT THAT GOOD IN MICROCONTROLLERS, BUT I AM A FAST LEARNER. PLEASE HELP....

19th November 2004, 05:43 AM	(permalink)
Nigel Goodwin	If you look at my HEX keypad tutorial I show how to make a keycode operated lock - you could simply replace the keypad reading routine with one for reading your BCD inputs. I would also advise (as usual!) that you drop the obselete 16F84, and use it's replacement the 16F628 - better spec and cheaper!. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

19th November 2004, 05:56 AM	(permalink)
samcheetah	hi MEHLULI, nice to see someone from Zimbabwe. ive also been to zimbabwe and its a very beautiful country. okay now as for your project. well, im also interested in using DTMF with PICs. the following link might be of some help to you. http://www.brouhaha.com/~eric/pic/dtmf.html as for learning PIC microcontrollers i would suggest that you read Nigel's tutorials http://www.winpicprog.co.uk

19th November 2004, 07:38 PM	(permalink)
MEHLULI	Re: Telephone as a remote control SECURITY FEATURES All my tutorial example does is wait for four keypresses, these are displayed on an LCD as they are pressed, and stored in four variables. Once the fourth one has been pressed it goes to a verification routine, this simply compares the four registers against the values set for the access code. If the code is correct is display so on the LCD, if it's incorrect it tells you that instead.[/quote] Thank you for that 8) So, even though I can not have an LCD can I still go thru that routine as it get it from the register in the PIC? I hope so. Now the real unclear part is that after the verification has passed, to getting in the controlling system, how is the input intepreted by the PIC? Can it be that easy to say wen code verified, then wen '1' is pressed can the signal goes straight as if we had no pic to activate appliance connected through that DTMF signal?