bdon003 wrote:
> I need to hook up a 3x4 Matrix Keypad to the board and have it send an
> interrupt when a key has been pressed.
[snip]
> Will I need to worry about debounce control inside the handler?
Yes. You are dealing with buttons and buttons bounce. I prefer a 20mS debounce
time. You may be able to use a shorter time depending on the buttons you use
but don't make it too short. Buttons can bounce more as they age. If your
debounce time is too short, you will start getting extra button state changes
as the buttons wear and age over time and use.
An alternative is to add an external IC to scan the keypad, handle the
debouncing, and generate an interrupt on valid button pushes. You can use a
device like the 74C922 (12-button) or 74C923 (16-button) to off-load dealing
with the keypad.
--
Cheers!
Kevin.
http://www.ve3syb.ca/ |"What are we going to do today, Borg?"
Owner of Elecraft K2 #2172 |"Same thing we always do, Pinkutus:
| Try to assimilate the world!"
#include <disclaimer/favourite> | -Pinkutus & the Borg
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