MULTIPLEXING???

Discussion in 'The Projects Forum' started by kdcouture2000, Dec 29, 2008.

  1. kdcouture2000

    Thread Starter Member

    Dec 6, 2008
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    i'm not sure how to multiplex two or more Seven segment displays. I could use some help. thatks. (how would you do it with out a micro-processor?)
     
  2. hgmjr

    Moderator

    Jan 28, 2005
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    Google using keyword "charlieplexing".

    hgmjr
     
  3. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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  4. SgtWookie

    Expert

    Jul 17, 2007
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    Go to OnSemiconductors' site:
    http://www.onsemi.com
    and download the datasheet for an MC14553B (4000 series CMOS 4553).
    It's a 3-digit BCD counter with a built-in multiplexer. It shows how to interface the IC with an MC14543B (4000 series CMOS 4543) BCD to 7-segment latch/decoder/driver, and how to cascade the counters to display six digits.

    No reason why you couldn't simulate the 4553 using a uC, and just use the 4543 as a driver for the displays.
     
  5. kdcouture2000

    Thread Starter Member

    Dec 6, 2008
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    that would be nice. however i do not know how to use microcontrollers, and i know you need to know C, C++ or even BASIC to program them. and that i have no idea how to do.
     
  6. hgmjr

    Moderator

    Jan 28, 2005
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    You should seriously consider learning microcontrollers since they can open up many new project ideas to you.

    hgmjr
     
  7. kdcouture2000

    Thread Starter Member

    Dec 6, 2008
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    were would you go to lean about microcontrollers. and the programing where would you go to learn that? One major question is do all microcontrollers accept the same programing language? and how do you interface them to the computer?
     
  8. hgmjr

    Moderator

    Jan 28, 2005
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    One good way to get into microcontrollers is to buy an evaluation kits. Cost is the main concern when it comes to these kits. You can breakdown the cost into two basic categories. One is the hardware and the other is the development software. The hardware includes a development board, a power supply, and a programmer. The software includes an Intergrated Development Environment or IDE. The IDE is loaded onto your PC and is used to write the program and download the resulting code to the target processor using the programmer.

    The two most popular microcontrollers are the PIC by Microchip and the AVR by ATMEL.

    I know the AVR has a full-featured IDE software utility available free from www.atmel.com. The C-compiler called WINAVR can be downloaded free from www.sourgeforge.net.


    You may want to find a beginner's book on microcontrollers and read it to get a better feel for the specifics.

    hgmjr
     
  9. beenthere

    Retired Moderator

    Apr 20, 2004
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    Multiplexing displays could be a bit more trouble than it is worth, although learning the technique can be quite valuable.

    What is being displayed, and why does the multiplexing seen necessary?
     
  10. kdcouture2000

    Thread Starter Member

    Dec 6, 2008
    13
    0
    my shop has these things called basic stamps. is this the type of kit you are refering?
     
  11. bertus

    Administrator

    Apr 5, 2008
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  12. SgtWookie

    Expert

    Jul 17, 2007
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    "Basic Stamps" are microcontrollers by Parallax, Inc.
    Their website is here:
    http://www.parallax.com

    If you click on the "Downloads" link, you'll be able to download documentation and software for various Stamps.

    Basic Stamps are programmed in a version of the BASIC language. It's relatively easy to learn, as the syntax is very English-like. They are fine for learning and prototyping. The manuals are pretty easy to read.

    The big drawback with Basic Stamps is that they are expensive to buy, so it would be cost-prohibitive to produce a commercial product using their products. One Basic Stamp costs 15 to 50 times as much as a Microchip PIC or Atmel AVR capable of performing the same function would. However, since you already have some of them in-house, there is no pressing reason to look elsewhere at the moment.
     
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