jstevenperry Posted January 1, 2006 Report Share Posted January 1, 2006 Does anybody have a good circuit diagram for how to hook up a matrix encoded keypad. It doesn't have to be 12 key, that's just what I have. If, say, you have one for a 16 key, I can extrapolate. I am trying to get this sucker breadboarded and it's driving me crazy. I's appreciate any help.Just for fun, what I'm trying to do is hook this keypad up in such a way that when I press a particular button on the keypad, a corresponding LED lights up. But it's not working, and I think that I've just got the wrong picture in my head (I'm not working from a schematic, just from what I think I know about how these suckers operate...they're just a matrix of switches, right?)...Here's a picture of what I've got so far, just to give you an idea of what I'm going for. Any help would be appreciated. Thanks. Quote Link to comment Share on other sites More sharing options...
ante Posted January 1, 2006 Report Share Posted January 1, 2006 Hi,This is how it looks inside, hope it helps! Quote Link to comment Share on other sites More sharing options...
jstevenperry Posted January 2, 2006 Author Report Share Posted January 2, 2006 Thanks, Ante. Then combine the output pins on the keypad with some AND gate logic and I should have it, right? Quote Link to comment Share on other sites More sharing options...
ante Posted January 2, 2006 Report Share Posted January 2, 2006 Yes, there are chips made for this job! Quote Link to comment Share on other sites More sharing options...
jstevenperry Posted January 3, 2006 Author Report Share Posted January 3, 2006 They're electromechanical, and work just like the picture Ante posted (except the pic he posted was for a 16 key, but conceptually no big diff...a 4x4 matrix versus a 3x4).The problem I'm having now is my AND gates (to produce a signal that corresponds to the exact switch in the matrix that was pressed) are doing weird things. I've posted that to a new topic, so not to pollute this topic. To me, the question I had regarding the 12 Key Matrix encoded keypad has been answered.Thanks to all for your replies! Quote Link to comment Share on other sites More sharing options...
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