Hi,

What I did for my 6x8 keypad consisting 48 keys.

I used a timer interrupt to scan the keypad preodically. Upon detecting a key pressed, I will keep on reading the keypad until the value changes back to normal (0xFF). Anything that's not 0xFF when I read back, mean that a key has been depressed.

I will continue to wait for 255 times in a for loop. Once the loop expire, I will exit out the ISR. Adjust this loop to suit your own taste or feeling.

WhatI get from this, is something similar (not 100%) to keyboard effect.

Hope this helps

Best Regards
Andy