Subject:
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Re: Expansion Board Servo timing...
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Mon, 12 Apr 1999 22:33:59 GMT
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Original-From:
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rmtmd <rmtmd@concentric.NOSPAMnet>
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Viewed:
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816 times
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How do you "de-initialize" a sevo? I am only familiar with the
init_expbd_servos(x) command and with reassigning the servo(x) global
variable to effect servo repositioning.
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
Gary Livick
> Drew-
>
> I have a Handy Board on a robot that runs three servos and the GP2D02 sensor,
> and I have the same nervous jitters problem. However, I do not run any
> processes on this application. I am using IC under v 3.2 of the software, so
> I could use processes but didn't. Look around on the site at
> http://www.acroname.com and find "Scooter Dude" in the gallery if you want to
> see what the application is
>
> I also have a Rug Warrior board powering a different robot, and it uses a
> servo to aim a sonar mast. I do see the effects of running processes on that
> in that the servo jumps from place to place, whereas when running the servo
> absent any other processes it runs smoothly. BUT it does not "jitter" like
> the Handy Board servos.
>
> I haven't dug into it yet, but there is obviously something fundamentally
> different about the way the Handy Board drives servos compared to the way the
> Rug Warrior does it. Because this is the case, I am not sure that allocating
> more run time for the servo process is going to fix it, but it is easy enough
> to try. After that, an intense study of the implementation technique on the
> Handy Board is in order. Let me know if you get time to look into that, and
> I'm sure others will be interested as well. One possible band-aide would be
> to de-initialize the servos between each finite change in their command
> state. That stops them from jittering because they are powered down.
>
> Gary Livick
> http://www.lightwaverobotics.com
>
>
>
> wengd@optionshealthcare.com wrote:
>
> > How sensitive are the exp bd servo routines to many processes running
> > concurrently. My servo works fine in a stand alone test file but when I
> > include it in my main code it gets the "nervous shakes", as if the timing
> > pulse is fluctuating ( I don't have a scope to verify this). The main code
> > starts separate processes for Sharp GP2D02, Photo, Bump, Pyro, User
> > (scans start button) and a Sonar which I disabled. Some of these
> > sensors are located on a servo controlled head. What's up?? Am I just
> > trying to do too much? Can the processes be assigned more or less
> > "ticks" to resolve this? Thanks for any suggestions.....
> > -Drew
>
>
RMT
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Message has 1 Reply: | | Re: Expansion Board Servo timing...
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| Hi Doc, The function call "init_expbd_servos(0);" turns them off, "init_expbd_servos(1);" turns them on. Something like "servo5=2300;" commands a servo to a position, but only if the servos are initialized as per above. Maybe I used a confusing term (...) (25 years ago, 12-Apr-99, to lugnet.robotics.handyboard)
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