>On Mon, 23 Aug 2004, Howard Winter wrote:
> I'm not sure either technique allows for multiple simultaneous key depressions, which was mentioned by the OP.
> As far as I can see, any simple x-y matrix will give ambiguity if two non-orthogonal keys are pressed at once.
> I wonder if a keyboard controller chip (I know they exist, I just don't know any!) would be the answer, since
> n-key rollover is part of what they do.

How about a keyboard controller chip made from a picf84
Try Tony Kubeks
http://www.piclist.com/techref/microchip/picboard.htm
I was able to make a 4x4 keypad talk to an IBM PC with
Tony's project and Fr. Tom's Keypad Project both with full
source and fully commented.
http://www.drzyzgula.org/bob/electronics/frtom.shtml

That was my first pic project after blinking a led :)
I was able to enter a two digit hex character and have the
F84 talk to the ps2 keyboard port on the pc and produce any
key character I wanted from a look up table.

~Kevin

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