Project: Object Counter

Discussion in 'The Projects Forum' started by masterdcj, Jun 23, 2008.

  1. masterdcj

    masterdcj Thread Starter New Member

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    Hey, am making a project which senses an object passing through a gate and counts the number (and displays it). For that i am using a 4-bit ripple counter IC (74LS293). I am displaying with 7-segment display.

    How can i drive two 7-segments using a single 7448 decoder?
  2. hgmjr

    hgmjr Moderator Staff Member

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    Can you supply us with a schematic diagram of your circuit at this point?

    hgmjr
  3. beenthere

    beenthere Retired Moderator

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    You should be able to multiplex the 7448. I'm amazed you have one. Original TTL IC's are hard to come by.

    Multiplexing is lots more trouble than just using another BCD-to-seven segment decoder.
  4. SgtWookie

    SgtWookie Expert

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    See the attached schematic. I drew this up quite a while ago when I was building a coil winder, to keep track of the number of turns; it wasn't really meant for general publication or it would be more neat. :rolleyes: It uses a Hall-effect device that senses when the shaft of the winder makes a complete turn.

    But of interest to you is the use of the CMOS 4553 and 4543 devices; one is a 3-digit BCD counter/mux, the other is the BCD to 7-segment driver. Pretty handy pair of CMOS IC's, and you can get them just about anywhere still. This just gives you a general idea on how to hook them up to drive three 7-segment LEDs.

    Note that Vdd and ground pins are not shown, nor are the 0.1uF bypass caps.
    Note that the 7-segment displays are common anode.

    Where on earth did you find the 7448?

    Attached Files:

    Last edited: Jun 24, 2008
  5. damilola

    damilola New Member

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    tell me all i need to know about a two digit counter which senses an object passing through a gate and counts the number (and displays it).
  6. SgtWookie

    SgtWookie Expert

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    See the circuit I posted?
    Use it.
  7. navid444

    navid444 New Member

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    can u post the program used
  8. SgtWookie

    SgtWookie Expert

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    The program that I used to create the schematic is Cadsoft DE's Eagle Layout Editor.

    You can download the current freeware version from Cadsoft's website:
    http://www.cadsoft.de/
    The freeware version is limited to single-page schematics, two layers in a board, and the size of the board is limited to about 3"x4". It is still quite useful, even with those limitations.

    It is confusing at first. Going through the tutorial is highly recommended.

    Here is another tutorial:
    http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=57&sipp=1&page=8
    You may actually wish to start with this one.
  9. hgmjr

    hgmjr Moderator Staff Member

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    If you are referring to the use of a program for the circuit, You do realize that the circuit does not use a microcontroller, right?

    hgmjr
  10. SgtWookie

    SgtWookie Expert

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    From a PM:
    Navid,

    I seldom help people via PM, particularly if they are new.
    1) This defeats the purpose of the board, by not sharing information with other viewers.
    2) This eliminates responses from other qualified individuals that you may otherwise have received.
    3) It fills up my PM box, which fills up rapidly enough.
    4) I don't generally use E-mail for replies either, as this would wind up consuming all of my free time. If you wish to be notified via Email of replies to your thread, you can "Subscribe to this Thread" under the "Thread Tools" drop-down list.

    You and the community are best served by starting a new thread in an appropriate forum. If you are not certain WHERE to post, start your thread in the General Electronics Chat by opening that forum, and clicking the "New Thread" icon. If a different forum would be more appropriate, a Moderator will move your thread there.
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