C routine for interfacing pic's and a dtmf decoder?

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iampic

Joined: 09 Sep 2003
Posts: 1

10 Dec 2003 20:53 dtmf pic

Anyone have a c driver to interface pic devices to a dtmf decoder (like Zarlink MT 8880 or MT 8870)?
Thanks, Iampic.

Mr_Programmer

Joined: 21 Feb 2002
Posts: 153
Helped: 4

12 Dec 2003 10:42 pic 8880 8870 8880 dtmf

iampic:
It's a 4bit BCD output, and the STD pin that informs you with a logic high level, that a DTMF tone was detected. Why do you need a driver ???
2 possibilities:

first: poll STD pin until you get a logical 1, this means a tone was received

second: put STD on a interrupt pin, if the interrupt occur, a tone was received

In both scenarios look for the BCD output, this will give you the information which tone was received.

Simple ... isn't it???

Greetings