Subject:
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RE: touch sensors aren't just switches (was Re: ideas for a RIS 2.0
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Newsgroups:
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lugnet.robotics
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Date:
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Wed, 25 Aug 1999 15:46:32 GMT
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Original-From:
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Jim Thomas <Jim.Thomas@trw.%saynotospam%com>
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Viewed:
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497 times
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You could always make a multiplexing circuit which does the thresholding and
debouncing for you. Once the status of each switch has been turned into a
binary state you could then use resistors to create a sort of D/A which
works reliably -- just as you wanted.
JT
-----Original Message-----
From: Robert Munafo [mailto:munafo@NOgcctech.SPAMcom]
Sent: Tuesday, August 24, 1999 7:55 PM
To: lego-robotics@crynwr.com
Subject: Re: touch sensors aren't just switches (was Re: ideas for a RIS
2.0
In lugnet.robotics, lego-robotics@crynwr.com (Tilman Sporkert) writes:
> Many "buttons" in today's electronic devices are designed that way. Check
> your TV remote control, your key-chain remote control for your garage door
> opener or car alarm, the buttons on your phone etc. It eliminates the need
> for a physical switch. All you need is a pair of copper pads under each
> button. These are just part of the normal circuit board that you need
> anyway. The rest is a hole in the cover, a piece of plastic ("the button"),
> a spring, and a small piece of conductive rubber.
I think it also removes the need to eliminate "keybounce", the annoying
thing
that happens with real switches due to dirt on the contact surfaces and tiny
arcs (sparks) just before initial contact.
Regardless, it seems to me that I'll do better making real switches. I was
planning on doing debouncing in software anyway (although I'd really rather
have gray coding in the multiplexer so I don't have to worry about that
either
:-)
Anyway, thanks for your responses and good explanations.
- Robert Munafo http://www.mrob.com/
LEGO: TC+++(8480) SW++ #+ S-- LS++ Hsp M+ A@ LM++ YB64m IC13
--
Did you check the web site first?: http://www.crynwr.com/lego-robotics
--
Did you check the web site first?: http://www.crynwr.com/lego-robotics
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