Subject:
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Re: 100 sensors
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Wed, 12 Mar 1997 05:43:39 GMT
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Original-From:
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MAR ERICSON <mar@cooper.(StopSpam)edu>
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Viewed:
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1591 times
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What's a resitor ladder?
Is there a textbook or something where I can get a schematic?
Is is same as a D-A converter?
-----------
ericson mar
Master of Engineering Candidate
Project: Mobile Robotics
mar@cooper.edu
(212)353-4356
Department of Mechanical Engineering
The Cooper Union for the Advancement of Science and Art
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On Thu, 16 Jan 1997, Richard Whitehead wrote:
> Joe,
>
> A very handy way to connect lots of digital switches is to arrange
> them in a resistor ladder and connect them into an analog input.
>
> You could get up to 8 switches into one input, giving you 256
> different voltage levels, in theory, but in practice 6 or 7 is more
> realistic without a lot of precision resistors.
>
> This means you need 16 analog inputs. You could use a couple of 1:8
> analog multiplexers to connect them all into 2 analog inputs on the
> HB.
>
> Maybe put a slow counter circuit on the multiplexer address lines, and
> input this to the digital inputs so you know which switches you are
> looking at at any one time.
>
> Hope this helps.
>
> Richard
>
>
> ______________________________ Reply Separator
> _________________________________
> Subject: 100 sensors
> Author: Joe Martin <Joema@mpx.com.au> at Internet-Mail
> Date: 16/01/97 04:04
>
>
> I am interested in sensing with about 100 water activated switches and am
> wondering if this is at all possible with the Handy Board.I had thought
> that it might be possible to by making them all return different levels of
> current at the sensor input I could make them register as different values
> to the handy board.Is this so or are there any other suggestions.
> Thank you,
> Joe Martin
>
>
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Message has 1 Reply:
 | | Re: 100 sensors
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| (...) A resistor ladder is simply several resistors, connected in series with a switch between each one. On the handyboard you would do something like this: VCC ---\/\/\/---\/\/\/--.../---...--- | | | | | | \ SW1 \ SW2 \ SW3 \ SW4 \ SW5 | \ \ \ \ \ (...) (28 years ago, 12-Mar-97, to lugnet.robotics.handyboard)
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Message is in Reply To:
| | Re: 100 sensors
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| Joe, A very handy way to connect lots of digital switches is to arrange them in a resistor ladder and connect them into an analog input. You could get up to 8 switches into one input, giving you 256 different voltage levels, in theory, but in (...) (28 years ago, 16-Jan-97, to lugnet.robotics.handyboard)
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