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7-Segment Display — Parallax Forums

7-Segment Display

BornaBorna Posts: 36
edited 2005-10-10 14:21 in BASIC Stamp
Hello All,
I'm very new to Basic 2 and I got a question on maybe someone can answer me.
I need to display a 4 digits number using 7-segment LED. I like to know if is possible to do something like that?
If is possible how is it done?
Also what is the alternative method of doing something like that? Maybe using a crystal LED?


Thanks
Borna

Post Edited By Moderator (Jon Williams (Parallax)) : 10/10/2005 4:32:05 AM GMT

Comments

  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-10-10 04:33
    Do you want to display four different digits on one physcial display, or do you want four digits (one digit per display)? If using just one display, it's very easy; if using four, then you should use a display multiplexer like the MAX7219 or the MC14489.

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    Jon Williams
    Applications Engineer, Parallax
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-10-10 04:45
    Borna,

    ·· Might you want to do something like in the thread listed below?· If so there's plenty of schematics and code there.· There's also examples of using the same chip in the StampWorks guide, which can be downloaded from our website in PDF format.

    http://forums.parallax.com/showthread.php?p=552892

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • BornaBorna Posts: 36
    edited 2005-10-10 13:03
    Hello Jon,
    when you said four different digits on one physcial display, are you talking about something like Serial LCD? If so is there some code example that I can review?
    Also Chris, the link above is very interesting, I'm reviewing that now.

    Thanks
    Borna
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-10-10 13:11
    Do you want a display that looks like this:

    8

    or like this:

    8888

    If the second, you really should use a display driver like the MAX7219 or MC14489 (less flexible, but cheaper).

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    Jon Williams
    Applications Engineer, Parallax
  • BornaBorna Posts: 36
    edited 2005-10-10 13:36
    like 8888. So MAX7219 or MC14489 are only the driver or the driver + LED?
    Thanks again
    Borna
  • Jon WilliamsJon Williams Posts: 6,491
    edited 2005-10-10 13:46
    The MAX7219 and MC14489 are just drivers -- you need to add your own LEDs. Or, you can get an MC14489 and 4 digits pre-built on an PCB by Reynolds Electronics (it's called the SLED4C). I think it's a little pricey at $29, but I can vouch that it works well. Look for the SLED4 at www.rentron.com.

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    Jon Williams
    Applications Engineer, Parallax
  • NewzedNewzed Posts: 2,503
    edited 2005-10-10 14:03
    You can see the SLED4 on my site.

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    Sid Weaver
    Do you have a Stamp Tester yet?
    http://hometown.aol.com/newzed/index.html

    ·
  • BornaBorna Posts: 36
    edited 2005-10-10 14:10
    ok guys thanks it is now clear. Also Sid, excellent info on your site.
    Thanks
    Borna
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2005-10-10 14:21
    Oh, and Borna, I mentioned the MAX7219 just because I had just used it in a project requiring 6 digits, but if you need 5 digits or less, the MC14489 is definately less expensive, and not too hard to use.

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
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