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robot cat in progress — Parallax Forums

robot cat in progress

Roboticsmaster128Roboticsmaster128 Posts: 32
edited 2012-01-19 20:09 in Robotics
my freind ttailspin on here convinced me that nothings to hard and im am now back on with the robot cat idea!i will be reporting my progress as i build and program the robot cat.:lol:

Comments

  • ElectricAyeElectricAye Posts: 4,561
    edited 2012-01-19 08:03
    For detecting a moving person, consider using a PIR:

    http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/pir/List/0/SortField/4/ProductID/83/Default.aspx

    You probably won't find anything that can recognize human faces for less than (insert your concept for too much money here).
  • Roboticsmaster128Roboticsmaster128 Posts: 32
    edited 2012-01-19 08:11
    Thanx electric eye! Now all I need is cheap 180 and 360 dergrees servos
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-01-19 08:23
    I'm not sure how many servos a Basic Stamp can control. I think it starts having trouble around four. You'll likely need some sort of external servo controller to controlling a lot of servos.

    The additon of
    Roboticsmaster128 wrote: »
    Please reply!
    to your post isn't likely to help in getting more replies. Some of us cranky old men might consider it rude (not this time but maybe the next:smile:).
  • ercoerco Posts: 20,256
    edited 2012-01-19 10:56
    @Rm128:

    Of course, real cats are plentiful and free. Just feed a stray and he's yours... :)

    Sounds like a pretty ambitious project. Have you scratch-built a few other robots already? What kinds?
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-01-19 11:03
    erco,

    How many servos can a BS2 handle before refresh becomes a problem? I'd assume it has a lot to do with what else is going on but do you have a rough estimate?

    Is Rm128 going to need some sort of external servo controller? (And I think I agree with your likely choice of ucontroller for this project.)
  • CircuitMageCircuitMage Posts: 62
    edited 2012-01-19 13:00
    +1 on the PIR sensor.

    Will your cat purr?
    Screetch, hiss and meow would be fun too. Short sound files too!
  • ercoerco Posts: 20,256
    edited 2012-01-19 14:42
    Duane Degn wrote: »
    erco,

    How many servos can a BS2 handle before refresh becomes a problem? I'd assume it has a lot to do with what else is going on but do you have a rough estimate?

    The most I've personally tried is 3 servos with a vanilla BS2E, which worked fine on a robot arm where not much else was going on:

    Four or five might be possible, probably if a faster stamp is used. But things like Sony SIRC IR remote control are out unless you offload to a Servopal, because just reading the IR code can take longer than the 20 ms pause between servo control pulses. Actually less than 20 ms with more than one servo.

    I just got a few of these $2 Turnigy servo reversers: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=17033

    My intent is to reduce processor overhead driving two servos when driving straight. Typically you have to send different opposing pulsouts (like 650, 850) to left & right CR drive servos to drive straight. With a servo reverser on one, you could send 650 to both, or even use one output pin to drive both. Of course then turning becomes a problem. It's never easy...

    FYI, those cheapie servo reversers work great, but they are not perfectly centered & symmetrical around 1500 ms, so each servo centerpoint must be recalibrated.

    In a related story, these $5 speed controls are only now back in stock at Hobby King, I ordered two:
    http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=9090
    This is an airplane throttle, not an H-bridge, so no reverse. But for $10 a pair, it's worth some experimentation. You could always throw in a DPDT reversing relay!
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-01-19 18:44
    Roboticsmaster128 wrote: »
    I have decided that this progect is WAY out of my reach. sorry if i have made any inconvenence to all who has posted or looked here :blank:

    Please don't delete posts like this.

    It makes all the work others have done trying to help you less meaningful to future readings.

    This is bad manners!
  • Martin_HMartin_H Posts: 4,051
    edited 2012-01-19 19:22
    CircuitMage wrote: »
    +1 on the PIR sensor.

    I see your PIR sensor and raise you one:

    12-29-2011.jpg
    12-29-2011.jpg
    1024 x 768 - 70K
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-01-19 19:40
    Martin_H wrote: »
    I see your PIR sensor and raise you one:

    Can you locate people with that setup? Very cool.
  • Martin_HMartin_H Posts: 4,051
    edited 2012-01-19 20:09
    Duane, that is the idea, we'll know shortly. I just started on this project as a fill in until my stepper controller arrives.
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