Magnetic angular sensors for robot wheel position

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smileymicros
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Posted by smileymicros: Thu. Apr 14, 2016 - 04:23 AM
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I once considered using a Hall effect sensor for determining wheel position, but as I saw it, you'd only get one revolution accuracy.

 

Recently I saw the angular magnetic sensors - with fractional degree accuracy, but they seemed kind of pricey.

 

Now I find that NXP has KMZ60 http://www.nxp.com/documents/dat... available from DigiKey for under $3 ($1.14 ea/1000) and this is getting close to inexpensive enough.

 

I'm not finding much on applications like robot wheel position so I'm wondering if anyone here has any experience with these things? Like maybe this is too good to be true (0.1 degree accruacy!) - so what are the gotchas?

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Learning and Information, General Electronics
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valusoft
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Posted by valusoft: Thu. Apr 14, 2016 - 04:52 AM
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Joe,

 

You don't have to post a slightly modified post... you should be able to use the edit button on your first post... unless of course you cannot see the edit button.

 

Cheers,

 

Ross

Ross McKenzie ValuSoft Melbourne Australia

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Kartman
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Posted by Kartman: Thu. Apr 14, 2016 - 06:20 AM
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The AMS5132 is around $7usd with a magnet from digikey. It resolves the angle into digital form. The KZ60 gives you a sine/cos analog voltage which you need to resolve.

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smileymicros
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Posted by smileymicros: Thu. Apr 14, 2016 - 02:50 PM (Reply to #2)
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That second post is news to me. I must have hit the wrong something.

 

And I'm not seeing how to delete it.

Last Edited: Thu. Apr 14, 2016 - 02:51 PM
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Torby
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Posted by Torby: Wed. Apr 20, 2016 - 01:15 PM
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You inadvertently quoted yourself. Echolalia perhaps?

 

That part sounds pretty cool. I once tried sensing wheel direction with 3 hall sensors and a magnet on the wheel. I figured in one direction, I'd see ABC ABC ABC ABC and the other, I'd see CBA CBA CBA and it would be pretty easy to detect. In practice, however, I'd see ABC ABC ABC ABC ABC CBA ABC ABC ABC ABC ABC CBA in one direction and CBA CBA CBA CBA CBA ABC CBA CBA CBA CBA CBA ABC in the other. 

The largest known prime number: 282589933-1

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js
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Posted by js: Wed. Apr 20, 2016 - 09:31 PM
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Quoted post deleted and strangely enough the thread did not disappear in thin air! laugh

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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