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From: totty@flute.cs.uiuc.edu (Brian Totty)
Newsgroups: sci.electronics
Subject: Re: Design a bar graph
Message-ID: <1990Nov3.185821.23815@julius.cs.uiuc.edu>
Date: 3 Nov 90 18:58:21 GMT
References: <16307@s.ms.uky.edu>
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Reply-To: totty@flute.cs.uiuc.edu (Brian Totty)
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Organization: Picasso Group, DCS, University of Illinois, Urbana-Champaign
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> I have three binary lines, for eight possible states (yeah, oh wow).  How
> can one light seven LED's from this, with zero having all LED's off and
> seven lighting all seven of them, in bar graph fashion?  A dot display is
> easy, but bar is tougher.  As a final touch, one should tax each digital
> line with but one standard TTL load. 

	I have seen a data sheet sometime in the last month that did what I
	think you want.  It could either display a bargraph (all LEDs
	up to value on) or just a single LED for the value.  It even provided
	for the cascading of these chips appropriately.  Unfortunately, I
	can't seem to find the data sheet for it now.  I'll keep looking.

	As a related question, are there any 4 bit -> 7-segment LED
	decoder/driver chips that represent the 4 bits in Hexadecimal
	rather than BCD with garbage for the top 6 values?


   /                      Brian Totty              o o
  /__  __  o       1304 W. Springfield Avenue       o  
 /  / /   /             Urbana, IL 61801           \_/  "We have corn in
/__/ /   /             totty@cs.uiuc.edu                Massachusetts too!"