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Driver circuitry for LED displays - newbie — Parallax Forums

Driver circuitry for LED displays - newbie

ArchiverArchiver Posts: 46,084
edited 2004-04-27 22:15 in General Discussion
Hi!

I'm working on an LED display using a 7 segment piece which has five LED dice per
segment, drawing more current then the BS2 can supply. Do you know where I can
find some good examples and/or schematics for that kind of driver circuitry I need?

Thanx

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2004-04-27 20:35
    Hello,

    You can use the MAX 7219 or 7221 for this project. Here is a link for
    more information:
    http://www.parallax.com/detail.asp?product_id=603-00001 . If you have
    any more questions please feel free to e-mail us.

    Thanks,

    Dave

    Dave Andreae
    Tech Support
    PH. 916-624-8333
    Stamp Support/ stamptech@p...
    Javelin Support/ javelinsupport@p...
    SX-Support/ sxtech@p...
    websites
    parallax.com
    stampsinclass.com

    Original Message
    From: mauriciocardieri [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=YEJ8q9KCY5mUi5ujgj3ide7rZj3zVz9wXbDUJGsleLWb0-Z3UbD2nldPD18eoIoCtnOdu5PI7QtYDOsHAmLQCxxIujg]mauricio.cardieri@e...[/url
    Sent: Tuesday, April 27, 2004 12:12 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Driver circuitry for LED displays - newbie

    Hi!

    I'm working on an LED display using a 7 segment piece which has five LED
    dice per
    segment, drawing more current then the BS2 can supply. Do you know where
    I can
    find some good examples and/or schematics for that kind of driver
    circuitry I need?

    Thanx




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  • ArchiverArchiver Posts: 46,084
    edited 2004-04-27 22:01
    Thanks Dave,

    But, after browsing the specs for the MAX72XX, i found that for driving LED segments
    w/ 3 or more LED dice the current supplied by the BS2 won't do. I'll still have to build
    some circuitry to increase the total current going thru the all the LEDs, but I have no
    experience on that...

    Thanks again!

    --- In basicstamps@yahoogroups.com, "Dave Andreae" <dandreae@p...> wrote:
    > Hello,
    >
    > You can use the MAX 7219 or 7221 for this project. Here is a link for
    > more information:
    > http://www.parallax.com/detail.asp?product_id=603-00001 . If you have
    > any more questions please feel free to e-mail us.
    >
    > Thanks,
    >
    > Dave
    >
    > Dave Andreae
    > Tech Support
    > PH. 916-624-8333
    > Stamp Support/ stamptech@p...
    > Javelin Support/ javelinsupport@p...
    > SX-Support/ sxtech@p...
    > websites
    > parallax.com
    > stampsinclass.com
    >
    >
    Original Message
    > From: mauriciocardieri [noparse][[/noparse]mailto:mauricio.cardieri@e...]
    > Sent: Tuesday, April 27, 2004 12:12 PM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] Driver circuitry for LED displays - newbie
    >
    > Hi!
    >
    > I'm working on an LED display using a 7 segment piece which has five LED
    > dice per
    > segment, drawing more current then the BS2 can supply. Do you know where
    > I can
    > find some good examples and/or schematics for that kind of driver
    > circuitry I need?
    >
    > Thanx
  • ArchiverArchiver Posts: 46,084
    edited 2004-04-27 22:09
    At 09:01 PM 4/27/04 +0000, mauriciocardieri wrote:
    >Thanks Dave,
    >
    >But, after browsing the specs for the MAX72XX, i found that for driving LED segments w/ 3 or more LED dice the current supplied by the BS2 won't do. I'll still have to build some circuitry to increase the total current going thru the all the LEDs, but I have no experience on that...
    >
    >Thanks again!

    Mauricio -

    Don't supply the current from a BS-2 pin, but rather directly from the power supply. That's the whole point of using such a driver. Some folks have driven up to 64 separate LEDs using this chip.

    Bruce Bates
  • ArchiverArchiver Posts: 46,084
    edited 2004-04-27 22:11
    Try:
    http://www4.tpg.com.au/users/talking/Construction-Part1.html

    This is a very nice site for the basics of
    providing more power using PIC-based circuits --
    which is what the BS2 is made of.

    --- In basicstamps@yahoogroups.com, "mauriciocardieri"
    <mauricio.cardieri@e...> wrote:
    > Thanks Dave,
    >
    > But, after browsing the specs for the MAX72XX, i found that for
    driving LED segments
    > w/ 3 or more LED dice the current supplied by the BS2 won't do.
    I'll still have to build
    > some circuitry to increase the total current going thru the all the
    LEDs, but I have no
    > experience on that...
    >
    > Thanks again!
    >
    > --- In basicstamps@yahoogroups.com, "Dave Andreae" <dandreae@p...>
    wrote:
    > > Hello,
    > >
    > > You can use the MAX 7219 or 7221 for this project. Here is a link
    for
    > > more information:
    > > http://www.parallax.com/detail.asp?product_id=603-00001 . If you
    have
    > > any more questions please feel free to e-mail us.
    > >
    > > Thanks,
    > >
    > > Dave
    > >
    > > Dave Andreae
    > > Tech Support
    > > PH. 916-624-8333
    > > Stamp Support/ stamptech@p...
    > > Javelin Support/ javelinsupport@p...
    > > SX-Support/ sxtech@p...
    > > websites
    > > parallax.com
    > > stampsinclass.com
    > >
    > >
    Original Message
    > > From: mauriciocardieri [noparse][[/noparse]mailto:mauricio.cardieri@e...]
    > > Sent: Tuesday, April 27, 2004 12:12 PM
    > > To: basicstamps@yahoogroups.com
    > > Subject: [noparse][[/noparse]basicstamps] Driver circuitry for LED displays - newbie
    > >
    > > Hi!
    > >
    > > I'm working on an LED display using a 7 segment piece which has
    five LED
    > > dice per
    > > segment, drawing more current then the BS2 can supply. Do you
    know where
    > > I can
    > > find some good examples and/or schematics for that kind of driver
    > > circuitry I need?
    > >
    > > Thanx
  • ArchiverArchiver Posts: 46,084
    edited 2004-04-27 22:15
    Hello,

    What type of power supply are you using? Did you look at the PDF file
    that is listed on the link that I sent you? It basically shows you how
    to program and wire it up. If you have any more questions please feel
    free to e-mail us.

    Dave Andreae
    Tech Support
    PH. 916-624-8333
    Stamp Support/ stamptech@p...
    Javelin Support/ javelinsupport@p...
    SX-Support/ sxtech@p...
    websites
    parallax.com
    stampsinclass.com

    Original Message
    From: mauriciocardieri [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=BY-Wg40kyG60S0AewuMqhfWSZXZjsL8s0o-crEXwEzoDm7UYZi8DH6ML2SXlS0X35pKcjMFFvLX5pM-aXg9WBo3ijgE]mauricio.cardieri@e...[/url
    Sent: Tuesday, April 27, 2004 2:01 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Re: Driver circuitry for LED displays - newbie

    Thanks Dave,

    But, after browsing the specs for the MAX72XX, i found that for driving
    LED segments
    w/ 3 or more LED dice the current supplied by the BS2 won't do. I'll
    still have to build
    some circuitry to increase the total current going thru the all the
    LEDs, but I have no
    experience on that...

    Thanks again!

    --- In basicstamps@yahoogroups.com, "Dave Andreae" <dandreae@p...>
    wrote:
    > Hello,
    >
    > You can use the MAX 7219 or 7221 for this project. Here is a link for
    > more information:
    > http://www.parallax.com/detail.asp?product_id=603-00001 . If you have
    > any more questions please feel free to e-mail us.
    >
    > Thanks,
    >
    > Dave
    >
    > Dave Andreae
    > Tech Support
    > PH. 916-624-8333
    > Stamp Support/ stamptech@p...
    > Javelin Support/ javelinsupport@p...
    > SX-Support/ sxtech@p...
    > websites
    > parallax.com
    > stampsinclass.com
    >
    >
    Original Message
    > From: mauriciocardieri [noparse][[/noparse]mailto:mauricio.cardieri@e...]
    > Sent: Tuesday, April 27, 2004 12:12 PM
    > To: basicstamps@yahoogroups.com
    > Subject: [noparse][[/noparse]basicstamps] Driver circuitry for LED displays - newbie
    >
    > Hi!
    >
    > I'm working on an LED display using a 7 segment piece which has five
    LED
    > dice per
    > segment, drawing more current then the BS2 can supply. Do you know
    where
    > I can
    > find some good examples and/or schematics for that kind of driver
    > circuitry I need?
    >
    > Thanx



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