AVR-Chat

At 02:40 PM 2/18/2005, Eric wrote:

>Oh-dam-it
>I forgot to say I was going to focus on the assembly code for now, and try 
>out my C coding after the book
>comes, that Amazon stuff up really got me worked up, I just got a email to 
>say one two piece order is on
>the way. I hope they picked up the double order mistake.


The easy way to do a matrix keyboard, is to take rows (or columns) and make 
them inputs pulled up, and take the other side (col or row) and make them 
the scanned outputs, active low.

So, when you are seeing all highs, no keys are pressed.
When you see a low on any row, then you check what col you have set low, 
and now you know what key(s) are pressed.