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Motion Control Camera — Parallax Forums

Motion Control Camera

KenLemKenLem Posts: 94
edited 2005-12-17 00:55 in BASIC Stamp
I've been thinking about making a·Basic Stamp controlled·servo driven motion control system for my camcorder.·· Has anyone tried something like this yet?

Thanks.


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Speech & Video IC's for BasicStamps

Comments

  • allanlane5allanlane5 Posts: 3,815
    edited 2005-12-14 21:41
    Asked and answered in regard to digital video. Basically, most people who do this want repeatability. The earlier answer said that the BS2 (and the servo) don't have lots of repeatability. The BS2 is pretty slow (2000 Basic Instructions Per Second) and a Servo either has 180 degrees of swing, or is 'continuous' and has very poor position control.

    However, if you only want to smoothly pan your camera (not in a completely repeatable way), then the BS2 and servo may give you a way to do it. If you want repeatable, the BS2 can act as the 'master' brain for other hardware (stepper motors, precision booms, etc), of course.
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-12-14 22:16
    As someone who actually uses a camera from time-to-time, I don't think the BS2 has any speed problem for this application -- there is no need to move a camera fast (watch a movie and you'll see the pans and tilts are deliberately slow to prevent anys strobing [noparse][[/noparse]less of a problem with video, but still exists]). I would use steppers for repeatablilty, though

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    Jon Williams
    Applications Engineer, Parallax
  • KenLemKenLem Posts: 94
    edited 2005-12-15 16:09
    >>Asked and answered in regard to digital video.
    Sorry. I did try a search before I posted but didn't find anything.

    I've poked around on google but haven't found anything at the hobby level. The only thing to do now is get the Basic Stamp and servo out and experiment! I'll try panning to see what I can do.

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    www.speechchips.com

    Speech & Video IC's for BasicStamps
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-12-15 16:57
    Ken,

    You'll find lots of stepper examples on our site; specifically attached to the stepper we offer and similar code in the StampWorks book. Here's a tip: If you use an L293D instead of a ULN2803 the code will work with unipolar or bipolar (easier to find in my experience) motors.

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    Jon Williams
    Applications Engineer, Parallax
  • KenLemKenLem Posts: 94
    edited 2005-12-15 20:32
    John,

    Thanks for the tip. Of course, stepper motors...

    Just to show you how old I am, (42) I had forgotten that I had built a motion controlled camera system using steppers years ago (1984 I think). I was a 2 axis custom built table system that moved a video camera back and forth over a map to digitize it with a frame grabber. The repeatablity was horrid. Just about that type, low cost ($5k) color scanners came out and it was easier to cut up the map and scan it.

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    www.speechchips.com

    Speech & Video IC's for BasicStamps
  • GuidoGuido Posts: 195
    edited 2005-12-16 02:38
    I have been working on a Pelco pan and tilt with feedback. You can do all kinds of crazy things. I purchased the unit on Ebay, and it works great, but it uses 120VDC Control for the motors. I have it working with the use of 2 LTC1298 for feedback. The Motor is very fast and the Basic Stamp 2 handles everything just fine. The 120VDC, motor has created some problems, as I am trying to control positions with a clock. The problom·I have had to deal with is the Noise from the Motors resetting the clock....Today I added more Filters and hopefully it will be fine. I do wish I would have gotten a 24VAC motor. Amazing what the basic Stamp 2 can do.
    Guido
  • John R.John R. Posts: 1,376
    edited 2005-12-16 04:48
    When the folks are talking about lack of repeatability, keep in mind that most of those discussions were targeted at repeatedly moving a camera over the EXACT same path to capture images for special effects and virtual reality type applications.

    If you're just looking to have remote control over a camera, and the forces required are not too bad, you should be all set. In this application (just controlling camera movement), I'd be more concerned about servos handling the forces.

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    John R.

    8 + 8 = 10
  • KenLemKenLem Posts: 94
    edited 2005-12-16 15:23
    Guido - Isn't ebay great.

    I found this current auction.
    http://cgi.ebay.com/PELCO-pt280-pan-and-tilt_W0QQitemZ7571240491QQcategoryZ46974QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

    John R. I'd love to have accurate repeatability but I don't think that is possible on a hobbist budget.

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    www.speechchips.com

    Speech & Video IC's for BasicStamps
  • GuidoGuido Posts: 195
    edited 2005-12-17 00:55
    Ken.

    Your doing alright....that is a good deal, hope you get it! You will be happy with it, one problem with Servo control would be the weight of the camera( and cost). I am still working on this unit as we speak, but am having a ba.ll with it. I am just learning all of this Stamp stuff and really am employed in a completely different field, so learning this has been all trial and error and some great help with this forum. If you won't laugh I will email a copy of my program for moving the camera to like 6 positions...Anyway have fun! And especially thank all these great people who will spend there time for us!
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