Need some help with keypads.

Discussion in 'The Projects Forum' started by unseen marine, Nov 24, 2010.

  1. unseen marine

    Thread Starter New Member

    Nov 24, 2010
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    Hey (I apologise if this is in the wrong place),

    On my current circuit (its a electronic poker chip device) currently the inputs are PTM which send out pulses, however, I would instead like to give the option for the user to input the amount they want with a key pad - its the 3 x 4 one from RapidOnline. However, I have no idea on how to code the E28 chip to work with it - how would you go about coding it??

    Best regards

    Josh

    P.S. I am using the latest circuit wizard.
    [​IMG]
     
  2. tom66

    Senior Member

    May 9, 2009
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    What is an "E28" chip?
     
  3. unseen marine

    Thread Starter New Member

    Nov 24, 2010
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    Its a pickaxe chip, its (I believe) made by Genie - who make circuit wizard.

    If you want I can take a screen shot of my current circuit - although I have removed the PTMs
     
  4. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    photo's will help?
     
  5. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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  6. unseen marine

    Thread Starter New Member

    Nov 24, 2010
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    Well I can't access Circuit Wizard till tomorrow, however, I can explain the chips I have in it to you.

    At the start I had 4 PTM's (with resistors to hold low) going into a C20 (like an E28 but less memory); from there the one output goes to a 4510 which goes to a 4511 - which goes to the 7 segment displays; thats the basic version of it.
     
  7. unseen marine

    Thread Starter New Member

    Nov 24, 2010
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    I have attached a picture of the wiring of the keypad I wired up, however, each row, when pressed i.e. for the first row with the LED. When either 1, 2 or 3 is pressed it lights up the LED even though its only meant to be 1....

    I have also attached the counting part of my circuit, i.e. the chips for the 7 segment display.

    Regards,

    Josh
     
  8. John P

    AAC Fanatic!

    Oct 14, 2008
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    I can't understand your circuit, but keypads are usually read by a scanning process. If you have a processor that can do that, it saves using any other components. Procedure is, ground one column and see if any row goes low; if not, ground the next column and see if any row goes low; if not, ground the last column and see if any row goes low; if not, nothing's pressed.
     
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