nouman wrote:.

 >I connect the phone line directly to the PIC with big resister protection
 >So the shape of ring in my country is like this  (Freq 20Hz)
 >
 >
 >5 V             _______            _______
 >             ___|          |_______|           |_____
 >0 V                   a          b
 >
 >
 >But last month I have send some devices to Saudi and it did not work
because
 >these devices did not detect the ringing  .......
 >any one knows what it might be the shape of ring signal in Saudia ......?

   Get PIC with ADC to your project in order to analize variable signal.
Phone
signals may vary dramatically depending on many reasons.

   Mike.

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body