Phone line processing-I NEED HELP

Archiver

Hello guys!.

I must project a system with PICs that allows two deaf
people to be able to communicate by telephone.

The system must have some way of warning with vibrator
and both will communicate by keyboard on telephone and
that information will receive it in display that later
I will see of what type can be.

As I do not know much on this signal processing, I
would thank for much if you have information about the
knowledge to make this project or some site that can
connect me with some practical application notes .

My limitation is the knowledge of the telephony
signals. I know that through the telephone line pass
voice and data.What I need is to simply process the
data .

I hope you can help me
Thank you very much

Gabriel Ciorciari
BS AS,Argentina





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Archiver

To Start off, I would use a RS232 keyboard to talk to a Stamp.
These are common with UNIX workstations and can be interfaced
easily and directly to a Stamp (1200 Baud - 3 Byte packets) from
there I would think about having the Stamp generate Audible
mark/space tones representing the 1's and 0's corresponding to
the keypress value. On the receiving end I would use a 567 tone
decoder (plenty of documentation on these) feeding a Stamp to drive
a LCD display. (Again plenty of documentation on this). Once
everything worked in "half-duplex" i.e. one direction I would
duplicated the circuit so that there are two Stamps on each end.
One to handle Keyboard and Telephone On/Off hook options, and the
other to listen to the phone line and drive a Display and Vibrating
and/or Strobe Light ringer.


>Hello guys!.
>
>I must project a system with PICs that allows two deaf
>people to be able to communicate by telephone.
>
>The system must have some way of warning with vibrator
>and both will communicate by keyboard on telephone and
>that information will receive it in display that later
>I will see of what type can be.
>
>As I do not know much on this signal processing, I
>would thank for much if you have information about the
>knowledge to make this project or some site that can
>connect me with some practical application notes .
>
>My limitation is the knowledge of the telephony
>signals. I know that through the telephone line pass
>voice and data.What I need is to simply process the
>data .
>
>I hope you can help me
>Thank you very much
>
>Gabriel Ciorciari
>BS AS,Argentina

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Beau Schwabe Mask Designer National Semiconductor Corporation
500 Pinnacle Court, Suite 525
Home: polygon_man@h... Mail Stop GA1
Work: bschwabe@a... Norcross, GA 30071

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