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From: rpluth@pnet01.CTS.COM (Ron Pluth)
Newsgroups: sci.electronics
Subject: Re: DTMF
Message-ID: <1405@crash.CTS.COM>
Date: Sat, 18-Jul-87 14:56:23 EDT
Article-I.D.: crash.1405
Posted: Sat Jul 18 14:56:23 1987
Date-Received: Sun, 19-Jul-87 06:35:43 EDT
Sender: news@crash.CTS.COM
Organization: People-Net [pnet01], El Cajon, CA
Lines: 15


   You can pick up a simple DTMF decoder chip at Radio Shack for $10.95.  It
outputs in straight binary for either the normal 12 digits or for all 16.  I
think it might also output in some other format, like Gray code, or something.
It takes, as has been mentioned, a cheap crystal, and I think it takes straigt
audio inputs.  Of course, you must be careful in interfacing it directly to a
telephone line, as ring voltages run up to ~150 VAC.

		                    Ron Pluth

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