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motor direction control — Parallax Forums

motor direction control

ArchiverArchiver Posts: 46,084
edited 2002-01-12 23:31 in General Discussion
Hello Everyone,

I am building a mini robot that is going to use mini DC motors for
driving. I am wondering if anyone could tell me how I can easily
control the direction of the motor with the basic stamp? Because of
the lack of space the smallest circuit would be most appropiate.
Thanks in advance!

Travis

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-01-12 22:07
    > I am building a mini robot that is going to use mini DC motors for
    > driving. I am wondering if anyone could tell me how I can easily
    > control the direction of the motor with the basic stamp? Because of
    > the lack of space the smallest circuit would be most appropiate.
    > Thanks in advance!

    Two common ways are to use an "H Bridge" or a DPDT relay wired so it
    will reverse the wiring to the DC motor. Do a search on "H Bridge" and
    you'll find all sorts of info. The relay is probably easier but
    perhaps not as elegant.

    Tim
  • ArchiverArchiver Posts: 46,084
    edited 2002-01-12 22:57
    I would use a L298N Dual H-bridge Motor control IC, there are also
    several other chips out there. www.alegro.com also has some motor control
    chips as well.
    Do a search on L298 on the web or goto www.digikey.com and search there, you
    can get the specs there as well.

    These types of motor control chips work good, in that you don't have to use
    PWM, or varying frequency (duty cycle) pulses, unless you really want to.
    Basically you allocate four I/O pins to the control. A 0,0 stop, 0,1
    forward, 1,0 reverse, 1,1 stop on each pair of pins is all you'd need at the
    minimum.

    If you want proportional or varying speeds, then take one pin low, and pulse
    the other at different frequencies (duty cycle) and you get a simp,le speed
    control.

    Since the L298 has dual H-bridges you can control two motors for
    differential steering.
    You can parallel the chips if you need more power.

    Original Message
    From: travis_gm [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=oUtZmuI_6jFh1MVJIRVNW_434j-9dB3fa5B8CuhHkFY8qW2IK-HKIDXBjNz3WQqfDMHO-R9H3lTd]travis_gm@y...[/url
    Sent: Saturday, January 12, 2002 3:04 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] motor direction control


    Hello Everyone,

    I am building a mini robot that is going to use mini DC motors for
    driving. I am wondering if anyone could tell me how I can easily
    control the direction of the motor with the basic stamp? Because of
    the lack of space the smallest circuit would be most appropiate.
    Thanks in advance!

    Travis




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  • ArchiverArchiver Posts: 46,084
    edited 2002-01-12 23:31
    A L293D would be most appropriate. It's a dual H-bridge driver IC for max
    600mA per motor. Is rather cheap (3.50 U$), much smaller then the L298 (no
    heatsink), directly Basic stamp (/TTL) compatible ,works great for PWM and
    uses no external diodes. Got good experience with it.

    alternatives for mini robot apps are to handwire a few multipurpose
    transistors, diodes and resisitors, but I think you would probably need more
    space for that. Especially when your current demands are higher (mostly the
    case using toy/cheap motors).

    A few links:
    http://focus.ti.com/docs/prod/productfolder.jhtml?genericPartNumber=L293D
    (datasheet)
    http://www.hvwtech.com/motorcontroller.htm (scroll down)
    http://members.aol.com/rich924/pub/l293.pdf (schematics)

    good luck,

    Matthijs

    Original Message
    From: travis_gm [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=rZNE4-Mvly18QepkVZCr13__qWk8GZdLEYDg_qOTkAyYnQumfK2qbezQbGEEPCH6x9IxNj0ab8quJtI]travis_gm@y...[/url
    Sent: Saturday, January 12, 2002 22:04
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] motor direction control


    Hello Everyone,

    I am building a mini robot that is going to use mini DC motors for
    driving. I am wondering if anyone could tell me how I can easily
    control the direction of the motor with the basic stamp? Because of
    the lack of space the smallest circuit would be most appropiate.
    Thanks in advance!

    Travis




    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.


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