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From: then@snakemail.hut.fi (Tomi  H Engdahl)
Newsgroups: sci.electronics
Subject: Re: flash LEDs with sound?
Date: 25 Apr 93 10:32:18 GMT
Organization: Helsinki University of Technology, Finland
Lines: 20
Message-ID: <THEN.93Apr25123218@lk-hp-11.hut.fi>
References: <199304241405.AA11067@kepler.unh.edu>
NNTP-Posting-Host: lk-hp-11.hut.fi
In-reply-to: dmn@kepler.unh.edu's message of 24 Apr 1993 09:05:22 -0500

In article <199304241405.AA11067@kepler.unh.edu> dmn@kepler.unh.edu (There's a seeker born every minute.) writes:

>     Would it be better to use a circuit based on the volume of the beeps
>on the cassette, or better for the leds to respond to a tone of a certain
>frequency? Is there any easy way to do either of these? I'm looking for 
>the simplest circuit possible. I guess what I'm asking for is some sort of
>color organ, but not quite. Let me trt to explain again...

Look for information about 567 tone decoder chip. It is an easy to use
chip for detecting sound of certain frequency. You need only one
567 and some other componets for each led you want to control.
The chip can take the voltage levels, which the casette gives.
Radio Shack Archer Semiconductor Reference Guide gives good information
how to use that chip. It should be simplest way to go. The chip costs
something like 1-2 $.
--
Tomi.Engdahl@hut.fi  !  LOWERY'S LAW:
then@niksula.hut.fi  !  "If it jams - force it. If it breaks,
                     !   it needed replacing anyway." 
* This text is provided "as is" without any express or implied warranty *
