23 thoughts on “KeyPad + Arduino P1

  1. Here is a nice App …
    Here is a nice App Note from ST about how to use JUST ONE ANALOG IN? PIN for an 10 Button KeyPad – Enter Google and search for “Using ST6 analog inputs for multiple key decoding”

  2. @kdarrah1234 Well …
    @kdarrah1234 Well you could get away with 4 io pins. Power 3 pins and have the other 4 pins hooked up to different resistors hoked up to one? analog pin

  3. @axel1973w yep, …
    @axel1973w yep, that’s a good idea, but it would be difficult to implement since the keypad architecture is already arranged in a row/column matrix. I? agree though!!

  4. Wasting 7 digital …
    Wasting 7 digital ports for a simple keypad ?!? make 7 digi ports ONE analog port using chained resistors and messuring the voltage on? the analog it should do it.

  5. @coasterboy5 Can’t …
    @coasterboy5 Can’t remember off the top of my head, but I just put the code link in the? description

  6. Hi what pins do you …
    Hi what pins do you link up to the arduino to the keypad?
    It would be most help full to find out 🙂

    And I’ve been looking at all your other? videos very interesting stuff not to mention helpful to =D

  7. To “Debounce”, I do …
    To “Debounce”, I do this:

    if(currentstate == HIGH && previousstate == LOW)

    That is if you have the external pull down resistor.

    And at the very ent you put

    previousstate? = currentstate;

  8. @stteneff good …
    @stteneff good point!! you have to test out that debounce timing. It took me a while to fine tune mine,? but it still screws up if I type it too fast

  9. I haven’t watched …
    I haven’t watched P2 yet, but what happens if your password is 11223 and you’re very? quick with typing 🙂

  10. @spasdar Well, in …
    @spasdar Well, in that case you wouldn’t need the resistor to ground since you are using a digital output pin to drive the input. That digital output pin can only be high or low. In the case of a button, the point of the pull up, or pull down resistor is to make sure of this. Still not sure about why your code isn’t working though. Make sure you haven’t enabled the pull up resistor internally… after you set the? input pin, make sure you don’t try to write to that pin

  11. @kdarrah1234? ah …
    @kdarrah1234? ah well i’m not using any buttons right now. i’m just testing it out with _one_ wire 🙂

  12. @spasdar hmmm… …
    @spasdar hmmm… not really sure what’s going on there. Well, part of the fun with these projects is troubleshooting. ? I think I even had problems with mine originally. I would recommend getting/building a continuity meter and test to see how the buttons are arranged in the grid… rows, columns

  13. so i’ve been …
    so i’ve been testing this out by connecting a wire from one pin to another with a 10k to ground between the pin and wire. then i have a simple code setup to light up a led when i insert the wire into the breadboard but i cant get it to work.

    i set the output pin to high, check to see if the input is high and if so, light up the led. i think i got the part with the resistor wrong because it works without it 😛 but theres almost a 2 second delay until the led turns off after i? unplug the wire

  14. @spasdar I’m …
    @spasdar I’m thinking you would probably want to use the mega; The duemilanove gives you 14 digital pins plus 6 analog pins, which you can use? for digital inputs as well, so you could do it, but you would be maxed out. The mega would probably be a better choice, because you could add other components to the project, like lights, buzzers, an LCD screen, whatever… good luck!!

  15. @nadav0ami thanks, …
    @nadav0ami thanks, more coming… hope I’m not boring anybody, there is always the back? button!

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