Subject:
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RE: Sonar Recentering Question
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Mon, 22 Mar 1999 22:22:55 GMT
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Original-From:
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Ted Mylenbusch <amylen@worldnetAVOIDSPAM.att.net>
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Viewed:
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967 times
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Just a suggestion but you could mount a Hall effect sensor somewhere near a
rotating rounded part on the cage and glue a small piece of magnet to the
rounded part. You could look for the pulse on a digital input. This way it
would not add much weight.
Alternatively, you could replace your motor with an RC servo which is very
easy to center and whose center pulse width, once determined, could be
placed in your code.
And lastly, adding only a couple of ounces, you could purchase a linear pot
(say 50k) and have the motor drive it's shaft also. Place a voltage across
the outer leads and measure the voltage across the wiper and ground when the
sonar is centered. Hook it up to an analog port and adjust that way. I
always flatten the wiper stop so it can rotate 360 degrees.
Hope these ideas help.
Ted Mylenbusch
amylen@worldnet.att.net
> -----Original Message-----
> From: rmtmd [mailto:rmtmd@concentric.net]
> Sent: Monday, March 22, 1999 1:25 PM
> To: handyboard@media.mit.edu
> Subject: Sonar Recentering Question
>
>
> I've rigged up a rotating cage holding the Polaroid 6500 transducer at
> the front of one of my bots. Every time I turn on the handy board, I'd
> like the software to begin by centering the transducer facing forward.
>
> I've rigged a micro motor to a bevel gear to drive the rotating sonar.
> The motor's axle passes through the Lego angle sensor. The problem is
> that whenever the handy board is switched off, lego3_counts is reset to
> 0, even if the sonar transducer is not facing directly forward.
> Persistent globals won't help, since they, too, are reinitialized when
> the handy board is switched on or the code is reloaded.
>
> My bot is heavy enough already. I'm loathe to add mechanical limit
> sensors to what is already a kludgy first attempt to get the whole thing
> working.
>
> Any thoughts?
>
>
>
> Ross M. Tonkens, M.D.
> Medical Director
> Primary Care of Nevada
> 100 North Green Valley Parkway
> Suite 240
> Henderson, NV 89014
>
> 702 914-7120 VOICE
> 702 914-7129 FAX
>
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Message is in Reply To:
| | Sonar Recentering Question
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| I've rigged up a rotating cage holding the Polaroid 6500 transducer at the front of one of my bots. Every time I turn on the handy board, I'd like the software to begin by centering the transducer facing forward. I've rigged a micro motor to a bevel (...) (26 years ago, 22-Mar-99, to lugnet.robotics.handyboard)
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