Hi all,
I know that for last 2 months or so i have placed lots of question over here and many think that i don't work hard on replies and just keep on asking questions ....

working on my project of design a 8 Lines Intercom using At89c52, MT8816 , no trunck line involved , only extension to extension talk and only Pulse Dialing Sets can work on this exchange.

I just want to know the following , that whether the following is possible through software or not . Iam not asking any one to take their time out and design the program for me i just want to know whether it is possible or not...


1) Detecting Pulse Dialing from a telephone Set, can i write a software which can detect pulse dialing from telephone sets and if yes can i write interrupts that can detect pulses in a condition if more than 1 telephone set is dialing as there are maximum 8 lines.?
(Like if i store 8 numbers representing 8 lines, then controller count the incoming pulses from telephone sets and compare it with the numbers stored in memory if the number match perform the desired function otherwise sent a Busy Tone to the extension dialing incorret number.)


2) Next can controller be used to sent call progress tones to telephone sets like DIAL TONE when ever any set goes off hook , ring back tone if the user dial corect number , busy tone in case if the dailed number is busy or if the dialed number is incorrect ?

3) Now if the Tone sending is possible i don't understand how can controller sent different tones if more than one set is in operation...like some set may require DIAL TOne and at the same time some may require busy, can controller be programmed to full fill this? like is there any oher technique like interrupt , somewhere i read i technqiue named Tme Division Multilexing etc..?

Iam asking these questions since there is no information avaiable for this on internet or in any book ...so i just want to know whether iam following a shadow or right path?