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Pan / Tilt camera using 2 servos+ BS2-IC (help)+ ? — Parallax Forums

Pan / Tilt camera using 2 servos+ BS2-IC (help)+ ?

ArchiverArchiver Posts: 46,084
edited 2002-11-20 15:05 in General Discussion
Help:

We need to move a camera and record
the pan & tilt moves, because we
need to repeat the same movements.


Servos, must be modified ?

Pan / Tilt must be without vibrations.
Any Idea.

Thanks : JOE
PS: Is it better the SSC
PS2: Is it possible to use VB to move servos
, speed, time , and recording this using BS2-ic?
or SSController is better.


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Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-10-08 12:23
    I see two options pretty quickly.

    use some feedback such as a potentiometer or encoder to record
    movement.

    use a stepper as the motor.

    I think the stepper might be easier as you would need an H-bridge for
    the fwd and rev movements and the stepper would need a dual H-bridge
    for each motor. and Allegro has stepper chips for small steppers.

    Remember, a stepper SHOULD be driven at between 5 and 20 times
    nameplave voltage, but no more than nameplate current. and if you
    take a uni-polar and drive it in bi-polar, full winding mode, you
    only need half the current to get the same power output.

    If you salvage some mini-steppers from an old printer, you may be
    able to use a darlington. a UNL2803 (8 circuits) could handle one
    (low power) motor and it has clamping doides to eleminate the high
    voltage spike that is created on every step as the magnetic files
    colapses.

    Dave




    --- In basicstamps@y..., Joe Terk <joeterk@y...> wrote:
    > Help:
    >
    > We need to move a camera and record
    > the pan & tilt moves, because we
    > need to repeat the same movements.
    >
    >
    > Servos, must be modified ?
    >
    > Pan / Tilt must be without vibrations.
    > Any Idea.
    >
    > Thanks : JOE
    > PS: Is it better the SSC
    > PS2: Is it possible to use VB to move servos
    > , speed, time , and recording this using BS2-ic?
    > or SSController is better.
    >
    >
    > __________________________________________________
    > Do you Yahoo!?
    > Faith Hill - Exclusive Performances, Videos & More
    > http://faith.yahoo.com
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-08 13:20
    Sounds like you need a good solid mechanism and mount to keep the
    vibrations down. What about the camera and lens that you will be
    attaching to the pan/tilt device? Will the lens need to have remote
    control zoom and focus? If so, will you also need to record the zoom
    and focus positions? I have specified and installed many of these
    devices over the years all have been off-the-shelf solutions though,
    no custom built hardware (pan/tilt heads, etc). However, some
    projects required custom programming for controlling pan/tilt heads
    and lens zoom/focus movements and positions. You also get into the
    question of speed control for the pan/tilt and lens (if applicable).

    ----Guy

    --- In basicstamps@y..., Joe Terk <joeterk@y...> wrote:
    > Help:
    >
    > We need to move a camera and record
    > the pan & tilt moves, because we
    > need to repeat the same movements.
    >
    >
    > Servos, must be modified ?
    >
    > Pan / Tilt must be without vibrations.
    > Any Idea.
    >
    > Thanks : JOE
    > PS: Is it better the SSC
    > PS2: Is it possible to use VB to move servos
    > , speed, time , and recording this using BS2-ic?
    > or SSController is better.
    >
    >
    > __________________________________________________
    > Do you Yahoo!?
    > Faith Hill - Exclusive Performances, Videos & More
    > http://faith.yahoo.com
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-08 16:17
    Try the recent article in Dr. Dobbs Journal where the author uses 2
    servos to do exactly what you want.
    http://www.ddjembedded.com/resources/articles/2002/0210f/0210f.htm

    Best,
    Sanjay

    Original Message
    From: Joe Terk [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=T2m36MwF69mhgGOvButGdKtDyqvlKZ9nb3iadlxYs87n-l05svp7EyvVyt3nFZxfRosWAhPD-Q]joeterk@y...[/url
    Sent: Monday, October 07, 2002 9:41 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Pan / Tilt camera using 2 servos+ BS2-IC (help)+
    ?

    Help:

    We need to move a camera and record
    the pan & tilt moves, because we
    need to repeat the same movements.


    Servos, must be modified ?

    Pan / Tilt must be without vibrations.
    Any Idea.

    Thanks : JOE
    PS: Is it better the SSC
    PS2: Is it possible to use VB to move servos
    , speed, time , and recording this using BS2-ic?
    or SSController is better.


    __________________________________________________
    Do you Yahoo!?
    Faith Hill - Exclusive Performances, Videos & More
    http://faith.yahoo.com

    To UNSUBSCRIBE, just send mail to:
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  • ArchiverArchiver Posts: 46,084
    edited 2002-10-09 01:43
    I remember an article in Nuts & Volts about a chip designed and sold
    to control two servos via RS232 commands. The writer worked for the
    chip maker (I think) and wrote some VB to talk to it. His project was
    a pan/tilt video camera. Let me know if you're interested and I'll
    start going through the mountain of old issues to see if I can find
    it.

    |
    | Read about a September 11th, 2001 hero @
    | http://larry-virgilio-fund.org/
    |
    Original Message
    From: "Joe Terk" <joeterk@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, October 08, 2002 12:41 AM
    Subject: [noparse][[/noparse]basicstamps] Pan / Tilt camera using 2 servos+ BS2-IC
    (help)+ ?


    > Help:
    >
    > We need to move a camera and record
    > the pan & tilt moves, because we
    > need to repeat the same movements.
    >
    >
    > Servos, must be modified ?
    >
    > Pan / Tilt must be without vibrations.
    > Any Idea.
    >
    > Thanks : JOE
    > PS: Is it better the SSC
    > PS2: Is it possible to use VB to move servos
    > , speed, time , and recording this using BS2-ic?
    > or SSController is better.
    >
    >
    > __________________________________________________
    > Do you Yahoo!?
    > Faith Hill - Exclusive Performances, Videos & More
    > http://faith.yahoo.com
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the
    Subject and Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2002-10-09 03:57
    Hiya,

    I have a PIC project on my website that details creating a serial
    servo controller chip that you communicate with at 2400 8N1 baud and
    it controls 4 servos. The resolution is 6 bits, the upper two bits
    define the servo. Source code is there as well as theory of op. If
    you can't program a PIC, I sell the chip for $8 - Just add a MAX232,
    or your favorite level shifter, and it'll work fine with a PC.

    No, I didn't write the N&V article, but I do remember reading it.

    have fun,
    DLC
    --
    Dennis Clark dlc@f... http://www.techtoystoday.com
    Author of "Building Robot Drive Trains" with Michael Owings.

    --- In basicstamps@y..., "Mark Abreu" <abe@c...> wrote:
    > I remember an article in Nuts & Volts about a chip designed and sold
    > to control two servos via RS232 commands. The writer worked for the
    > chip maker (I think) and wrote some VB to talk to it. His project was
    > a pan/tilt video camera. Let me know if you're interested and I'll
    > start going through the mountain of old issues to see if I can find
    > it.
    >
    [noparse][[/noparse]snip]
    > > Help:
    > >
    > > We need to move a camera and record
    > > the pan & tilt moves, because we
    > > need to repeat the same movements.
    > >
    > > Servos, must be modified ?
    > >
    > > Pan / Tilt must be without vibrations.
    > > Any Idea.
    > >
    > > Thanks : JOE
    > > PS: Is it better the SSC
    > > PS2: Is it possible to use VB to move servos
    > > , speed, time , and recording this using BS2-ic?
    > > or SSController is better.
  • ArchiverArchiver Posts: 46,084
    edited 2002-11-20 15:05
    Thanks Dave:

    Yes, steppers could be better.
    I understand the feedback , but
    any idea about how can I record and
    play movements later. ?

    Many thanks : Joe

    --- Dave Mucha <davemucha@j...> wrote:
    > I see two options pretty quickly.
    >
    > use some feedback such as a potentiometer or encoder
    > to record
    > movement.
    >
    > use a stepper as the motor.
    >
    > I think the stepper might be easier as you would
    > need an H-bridge for
    > the fwd and rev movements and the stepper would need
    > a dual H-bridge
    > for each motor. and Allegro has stepper chips for
    > small steppers.
    >
    > Remember, a stepper SHOULD be driven at between 5
    > and 20 times
    > nameplave voltage, but no more than nameplate
    > current. and if you
    > take a uni-polar and drive it in bi-polar, full
    > winding mode, you
    > only need half the current to get the same power
    > output.
    >
    > If you salvage some mini-steppers from an old
    > printer, you may be
    > able to use a darlington. a UNL2803 (8 circuits)
    > could handle one
    > (low power) motor and it has clamping doides to
    > eleminate the high
    > voltage spike that is created on every step as the
    > magnetic files
    > colapses.
    >
    > Dave
    >
    >
    >
    >
    > --- In basicstamps@y..., Joe Terk <joeterk@y...>
    > wrote:
    > > Help:
    > >
    > > We need to move a camera and record
    > > the pan & tilt moves, because we
    > > need to repeat the same movements.
    > >
    > >
    > > Servos, must be modified ?
    > >
    > > Pan / Tilt must be without vibrations.
    > > Any Idea.
    > >
    > > Thanks : JOE
    > > PS: Is it better the SSC
    > > PS2: Is it possible to use VB to move servos
    > > , speed, time , and recording this using BS2-ic?
    > > or SSController is better.
    > >
    > >
    > > __________________________________________________
    > > Do you Yahoo!?
    > > Faith Hill - Exclusive Performances, Videos & More
    > > http://faith.yahoo.com
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed.
    > Text in the Subject and Body of the message will be
    > ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to
    > http://docs.yahoo.com/info/terms/
    >
    >


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