Newsgroups: comp.robotics
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From: cs911225@ariel.cs.yorku.ca (KEN E WILLMOTT)
Subject: Re: problems with miniboard
Message-ID: <CJ2AqH.D4J@ariel.cs.yorku.ca>
Sender: news@ariel.cs.yorku.ca
Organization: York University, Dept. of Computer Science
References: <gBTDFc2w165w@sys6626.bison.mb.ca> <CIyowo.MAp@demon.co.uk>
Date: Mon, 3 Jan 1994 16:20:41 GMT
Lines: 26

>From: Marc Nicholas <marc@rednet.demon.co.uk>
>(Anyone is welcome to flame me if I'm wrong here...)

Okay! :-)

>Any unused pins on a chip like the HC11 should be connected to
>*something*....i.e. ground or logic 1....

>Why? Well, it's standard CMOS practice and I presume it's relavent
>here...but I'm no electronics engineer....

>Marc.

>(I'm just about to start building a miniboard without any motor drivers,
>no SPI jacks, and no LEDs so I'd welcome any feedback!)


Marc,
That should read "Any unused *input* pins....". You would never
tie an output to ground or power that way. In that case, an
output that was inadvertently set to the other logic state
would be short circuited, causing the chip to overheat.
So, just tie up your unused inputs.

	-Ken

