Subject:
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Re: Questions, questions, questions......
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Wed, 10 Jul 1996 12:56:07 GMT
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Original-From:
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Fred G. Martin <fredm@media.%spamless%mit.edu>
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Viewed:
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1751 times
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> What are the hardware-imposed software differences between the
> HandyBoard and the 6.270/Rug Warrior boards ? ie it looks like the Rug
> Warrior motors are controlled directly by Port A lines. Are these
> outputs configured as digital I/O or are they still under the control
> of the timer subsystem ? (I think that the 6.270 board is setup in a
> similar way, but I don't have the schematics on hand to check.) If the
> 6.270/Rug Warrior board does use the Port A timer interrupt lines to
> do PWM, does this mean that the available motor power levels on the
> 6.270/Rug Warrior board has finer granularity than the 8 speeds on the
> HandyBoard ? (I'm trying to port the Rug Warrior code from the Mobile
> Robots book to my HandyBoard....)
The Handy is like the 6.270; both have dig out latches going to the
motors. The RW drives the motor ctrl pins directly.
A re-write of the system PWM routines could provide finer than 8
levels of control, even w/o needing HW timer lines.
> I'd also like to add some extra I/O to the HandyBoard, does anyone (ie Fred)
> have exact measurements for the distances between pin 1 on the following
> connectors ?
> J8 J13 J3 U4
>
> ie
> U4 J3
> +ooooooooooooo +ooooooooo
> <--------------> ^
> ??? |
> | ???
> ??? |
> <------------------> |
> oooo ooo+ +
> J13 J8
good Q.
Betw U4 and J3, it's just 0.1" spacing, so count the pins. There's an
extra 0.1" space between the two headers.
from the left-most (GND) pin of U4 to the left-most pin of J13, the
offset is 0.0" horizontally and 2.50" vertically.
from the left-most (GND) pin of U4 to the left-most pin of J8, the
offset is 1.75" horizontally and 2.50" vertically.
> And my final question...
> Where do I plug in an RC servo ? From the look of the servo.asm code shipped
> with the beta version of IC 3.1 it looks like PA7 (J2 pin 9) is used by the
> servo code, is this correct ? Has anyone tried hacking IC to use TOC3
> (available on the expansion connector - J3) as a servo output ? I know that
> it's possible to use the beeper TOC instead, but it looks like TOC3 isn't bei • ng
> used on a standard HandyBoard.
See the instructions in the printed IC manual for connecting to PA7 =
J2 pin 9.
Yes, the servo code could easily be revised to use the spare TOC3 out
on the exp header. go for it.
Best,
Fred
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Message is in Reply To:
 | | Questions, questions, questions......
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| Hi I've just built my first HandyBoard (thanks for the great service Prabal), and have a few questions (that I can't find in the FAQ). What are the hardware-imposed software differences between the HandyBoard and the 6.270/Rug Warrior boards ? ie it (...) (28 years ago, 10-Jul-96, to lugnet.robotics.handyboard)
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