Hi there... I have a 4x6 button matrix that leads out to a 10 pin ribbon cable. I have the datasheet and how it works is each button closes two of the leads on the ribbon cable so you can see which button was pressed.
How would you read the buttons if you plug it directly into the Arduino's digital pins? I can't seem to figure out how to "sense" a closed circuit. Do I fire +5v down one pin and see which line it comes out on? If nothing comes out with voltage on the first pin, then cycle down each of the leads until I get voltage coming back? For example on a 4 lead ribbon cable I do this...
|||| +--- Nothing
|||| -+-- Nothing |||| --++ Ah! I fire +5 down 3 and I get it back on 4, meaning that pins 3 and 4 are "shorted" and therefore button x is pressed!