Need help with digital counter kit.

Discussion in 'The Projects Forum' started by Nser Uame, Dec 27, 2013.

  1. Nser Uame

    Thread Starter New Member

    Dec 27, 2013
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    I have done much circuitry, and none in years, but a current project requires me to have a digital counter. I constructed the piece as per the image provided to copy and it turns on, the rotary encoder works in the sense that it goes up and down, and resets the count by push, but the problem is it only counts to 1 before restarting at 0. Pictures below (keep in mind, I have re-done everything 3-4 times to try and figure it out, so it looks pretty shocking)
     
  2. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    A schematic would be better to have.
    I see a chip that has been "wiped off".
    It is likely to be a pic-like chip that is programmed to be a counter.
    Did you check if there are no shorts between tracks and connections?

    Bertus
     
  3. Nser Uame

    Thread Starter New Member

    Dec 27, 2013
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    Hey, Bertus.

    I'm not sure what you're referring to that has been "wiped-off" and thus, the following sentence made no sense to me either. You may have to use a layman's terms for me. Here are the schematics. Thanks for giving me some help!
     
  4. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Have a look at the annotated spots:

    [​IMG]

    There are possible some shorts there.

    Bertus
     
  5. Nser Uame

    Thread Starter New Member

    Dec 27, 2013
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    None of those are actually touching, except for the one that obviously is, and it shouldn't matter as the circuit follows that route anyway? I cleaned it all up a bit after I took the photo and it's still the same result. Counter only goes to 1. Is there any other possible issues? Thanks again.
     
  6. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    Could you make a sharper picture of the solder side of the PCB?
    I would use a fladbed scanner for this as in my example below:

    [​IMG]

    That way there will be a steady picture.

    Bertus
     
  7. Nser Uame

    Thread Starter New Member

    Dec 27, 2013
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    Well, my new scanner's not installed, etc. yet, so maybe tomorrow. I've scoured the back up and down over and over, nothing's touching. If that's your concern. Could there not be another problem?
     
  8. MrChips

    Moderator

    Oct 2, 2009
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    Could you provide a link to the source of your kit?
     
  9. Nser Uame

    Thread Starter New Member

    Dec 27, 2013
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    I got it off of eBay. The seller told me to come to this site for help. To ask for SGT Wookie. I can't get the exact link right now, I'm on my phone... but if you type "UP/DOWN DIGITAL COUNTER" it should be one of the first items. I'll get a scan for Bert and a link for you in the morn :). Thanks for the help.
     
  10. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    I am traveling today and don't have the time to try to help, but I think that the kit is a K129 from Kits R Us. Here is the circuit description and schematic.

    http://www.kitsrus.com/pdf/k129.pdf

    ETA: Maybe not. K129 looks very similar, but not quite the same.
     
    Last edited: Dec 27, 2013
  11. MrChips

    Moderator

    Oct 2, 2009
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    The MCU is 18-pin with xtal on pins 15 & 16. Possibly PIC16F54.
     
  12. MrChips

    Moderator

    Oct 2, 2009
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    Give us the make and model number of the rotary shaft encoder. The problem could be the way the encoder is wired.

    Remove the 1k and 100kΩ resistors to the right of the encoder and see what happens.

    Also, do you have the source code for the MCU?
     
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