Subject:
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Re: how many servos on handyboard?
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Wed, 17 May 2000 05:06:09 GMT
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Original-From:
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Will Bain <WILLB@SELWAY.nomorespamUMT.EDU>
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Viewed:
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892 times
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Vic wrote:
>
> I'd like to know how many servos the handy board can control. On the FAQ it
> says 2, in the documentation it says 4 DC motors. what's the deal? (am I
> stupid? I'm new at this)
The deal is this: Servos are different from plain old DC motors. They have gearing and position control circuitry built in.
There are four DC motor ports on the basic HB, but no ready-made servo ports. The dual servo routine described on the HB web site makes use of Port A bit 7 (aka digital port 9) and Port A bit 5 (on the expansion bus (back edge of board, under the LCD)).
> also, when you plug an expansion board, do you get 6 EXTRA servos? or those
> are the only ones you can still use? How about the rest? do all imputs
> remain free on the handyboard and everything on the expansion board is
> extra? than you.
I think you could in fact get six *extra* servos. The expansion board doesn't affect the use of Port A bit 7 (aka digital port 9), and I saw instructions on the HB web site (Software Contributed section) on how to use the piezo beeper to control a servo, too. The expansion board does occupy the expansion bus, though, precluding the use of Port A bit 5. Still, I think you could run eight servos with the exp. board. Should probably use a separate battery pack.
If you want to run a lot of servos, try using a serial servo controller (SSC). Check out the offerings at http://www.seetron.com/. Each SSC can run up to eight servos, and you can daisy chain a bunch of SSCs together to run up to 256 servos. The SSCs can be plugged into Port A bit 7 (aka digital port 9). Instructions are on the HB web site. Best of luck!
-- Will
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Message is in Reply To:
 | | how many servos on handyboard?
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| I'd like to know how many servos the handy board can control. On the FAQ it says 2, in the documentation it says 4 DC motors. what's the deal? (am I stupid? I'm new at this) also, when you plug an expansion board, do you get 6 EXTRA servos? or those (...) (25 years ago, 16-May-00, to lugnet.robotics.handyboard)
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