Want A Counter Having Reset Button And Range Up to 9999(4 digit 7 seg.)

Discussion in 'Homework Help' started by aq_rules, Jun 24, 2010.

  1. aq_rules

    Thread Starter Member

    Oct 28, 2009
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    I want a schematic of such type of counter having the reset button and a count button(it will act like a trigger or it will be a push button),LCD displays a number everytime tht button is pressed..if tht button is pressed 5 times it displays 5 on the LCD
    Max Count will be till 9999.
    Plz help Me..
     
  2. retched

    AAC Fanatic!

    Dec 5, 2009
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  3. aq_rules

    Thread Starter Member

    Oct 28, 2009
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    how to write these files to an IC??
     
  4. retched

    AAC Fanatic!

    Dec 5, 2009
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    You write them to a uC (microcontroller) like a PIC.

    You will need to use a PIC programmer like a PICKIT2.

    There are many other programmers available. You may ask a friend to use theirs, or you can upload the code to microchip.com and they can program the PIC and send you the chip. That way you dont need to program it yourself.
     
  5. n1ist

    Active Member

    Mar 8, 2009
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    If you don't want to use a micro, look at the ICM7224 chip. You may need to add some debouncing to the count input.
    /mike
     
  6. aq_rules

    Thread Starter Member

    Oct 28, 2009
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    i dint understand, wht kind ov debouncing...
     
  7. Wendy

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    Mar 24, 2008
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    Something like this...

    [​IMG]
     
  8. retched

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  9. aq_rules

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    Oct 28, 2009
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    If i use a relay instead of a push button or switch will it work??
    This relay will be connected to a infrared beam barrier circuit(having two parts)...for example a person passes through tht barrier with an average speed the relay will be active until the beam is not in contact with the other part of circuit..as the beam contacts other circuit relay goes off...plz rply soon
     
  10. retched

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    Relays still bounce. You need to de-bounce the signal from the relay. If you dont, you may count 3 or 5 or 15 counts for every 1 your trying to count.

    I suppose you could use a SSR (Solid State Relay) to avoid bouncing.
     
  11. beenthere

    Retired Moderator

    Apr 20, 2004
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    They latch on when using DC.
     
  12. aq_rules

    Thread Starter Member

    Oct 28, 2009
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    shall i use a solid state relay?
     
  13. beenthere

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    Apr 20, 2004
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    By "latch on" I mean that the SSR will remain on once triggered until power is removed from the circuit. That is not good pushbutton behavior.
     
  14. retched

    AAC Fanatic!

    Dec 5, 2009
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    beenthere is correct. You will have to cut power in order to "turn-off" the relay.

    There is a whole internet out there with circuits and topics on de-bouncing.

    If you do a search in the forum, you will find many ways to de-bounce the switch.

    If you find one that looks like you can handle, post it and we will see what we can do.
     
  15. aq_rules

    Thread Starter Member

    Oct 28, 2009
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    what about two plates of steel contacting together when displaced ?? i own re rolling mill in which we manfacture iron rods(used for construction)...when a iron rod comes from the machine displacing that steel plate over the other plate acting like a switch will it create any de bouncing thingy??
     
  16. tom66

    Senior Member

    May 9, 2009
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    I think you're talking about an SCR, silicon controlled rectifier, or a TRIAC, triode for alternating current. A solid state relay is just a MOSFET with its gate light coupled. A solid state relay does not latch, unless it is particularly designed to, or unless latchup occurs... if that even happens with an SSR.

    You will need debouncing on pretty much any switch unless it is specifically designed to not bounce (it might be mercury wetted for example) or it already has debouncing logic built in (unlikely.)

    If you want a discrete simple solution, you can use 4x CD4026 (or similar 4026 series) ICs. Each IC handles one digit and increments the next counter at tenth the rate of the input signal. Wiring them in series, with the "ungated 'C' segment" output wired to the input of the next counter would be a simple system, though it has its costs, and there is no easy way to record the input using a microcontroller or handle special cases like counting two at a time, it's a simple solution. Sometimes the simplest solution works best. A reset button could wire to pin 15 of the ICs, or it could temporarily switch off power to the chips (think pulling down the Vcc of the chips.)
     
    Last edited: Jul 6, 2010
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