I am building this "PBX" to handle 2 lines.

Because of the specialized circuitry, the incoming lines do not ever connect
to the telephone sets.  So you have to detect the ringing line, capture the
CallID info, ring the sets that you want to ring and feed these sets the
CallID data.

I purposely wanted to design the system to use any regular off-the-shelf
residential telephones.  If you buy a set that has Caller ID ability, I want
to be able to display the name/number.  This is also true if you make a call
to another extension.  I want to be able to display the extension that is
calling.

I am not experienced enough to design my own FSK Modem software.  So either
a chip that can do this or PIC software to do this is what I need to send
the data to the sets.

There are plenty of chips that can decode the incoming data, but if I can
get PIC software to do this as well, then I am all set.

John Mullan


-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Alan King
Sent: Tuesday, February 01, 2000 3:43 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: Another CallerID / PIC question.


How are you doing the ring to the extensions?  I am assuming you only have 1
line
coming in though to repeat..
  Have a similar multi-incoming line setup at the Domino's I work at at
night.
But they decode once, then send the data serially.  Can't imagine taking it
back
up to the encoded level once you have it down to serial..

John Mullan wrote:

> But has anyone successfully "sent" caller id data using a PIC.
>
> I am building a small telephone switch with the PIC16F874 as the brain.
> However, since the incoming (CO) line is not directly connected to any
> extension, the data does not get transfered to the extensions sets
(assuming
> CallID capable sets).
>