Ravindra Divekar wrote:
>
> somebody please tell me whether a
> X-Y key matrix is efficient, if i
> am checking for key combinations
> rather than single-key presses.
> i ask because the 16c84 has only 1k
> of code space, and key matrix
> scanning consumes a lot of space.
>
> --Ravindra

It is perfect for the job. If, for instance you have a 4X4
keypad, you can use 4 inputs and 4 outputs on the same port.

The port value will be unique for *any* combination of keys.

Moreover, if your debounce routine validates the key(s) upon
leaving the key, you can also have special meanings attached
to keys that are pressed for longer than, say, a second.

--
Friendly Regards

Tjaart van der Walt
mailto:tjaart@wasp.co.za
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