so close! (a few buttons and leds don't work)

  • hi, my 40h keypad kit + arduino logic is almost done, but a have a 3 problems.

    1) One Full row of LEDs don't work:
    -I tested every single LED with a battery and they are all good.
    -Tested diodes with multimeter. apparently all my diodes have a 6.5ohms resistance going one way, its kinds of an inconsistent measurement.

    2) One full row and one full column of buttons don't work.
    -don't know what could cause this.
    -the LEDs associated with the buttons can be light manually in Monome_Test

    3) Two random buttons don't work

    I'm not really sure what to do.

    In another post there is talk of a faulty shift register? Can anyone elaborate on this. Is there a way to troubleshoot that?


  • I found when this happened to me, it was just a bad solder joint, they may look good but doesn't mean it is, i would double check all of them, and make sure the diodes are the correct direction, just one off will mess up a whole row also.

  • is there a correlation between a keypress not working and an led not working? cause most of my led malfunctions have working keypresses and most of my keypress malfunctions have working leds.

    is there a way to isolate the problem before resoldering (so i just resolder the faulty joints)?

  • When i ha problems with a keypad not responding, it was almost always the diode with a missing solder joint, or a diode wired backwards. Any time my LEDs were not working, it was a bad solder joint on the LED or it was wired backwards.