Matrix Keypad routine

[mister_e]

OK NO NEED FOR THAT

i've attach the latest version... which i thought i had posted here


So the only thing you will have to do, is to add this simple line

DEFINE SCAN_ONCE 1

And this should cure the problem.

I have added this feature once i needed to scan a keypad with a timer interrupt... which is certainly the way to go for any Push-Button/Keypad entry anyways.

Enjoy!

[passion1]

Steve

EXCELLENT!! Now everything works 100%!

One last question:
What is the debounce and autorepeat functionality as set by

DEFINE KEYPAD_DEBOUNCEMS 200 ' debounce delay = 200 mSec
DEFINE KEYPAD_AUTOREPEAT 1 ' use auto-repeat feature

Thanks again!

[mister_e]

Let's say the user press on a specific key for awhile, the AUTOREPEAT feature should allow to scan/give you the Keypad scan each 200mSec.. handy? Not sure of it In your case, of course not.

Debounce delay will be the delay the software will wait after a key have been pressed before to go out and giving you the right Key. On most tact-switch keypad, 100 mSec is more than enough, but.. the best way to know it, is to test it.

Glad to know it's working now!

[passion1]

Steve

Thus, am I right in saying that if I want the keypad scanner to interfere the least with the rest of the program execution, then I must switch the AUTOREPEAT OFF?

[mister_e]

If you don't define AutoRepeat, the program will spin in round until you release the keys.

To make a short story Use AutoRepeat and SCAN_ONCE... i should have written that routine in a different way...

[Ioannis]

Maybe using Darrel's Instant Interrupts? Just an idea...

When I have some spare time I'll try it to have a true multitasking keyboard scanner.

Ioannis

[CluckShot]

I have noted this discussion on Pull Up resistors. I am running the PIC18F series chip and it in the documentation says it supports a weak pull up setting internally in the chip. Could I get any discussion of this relative to the pull up resistors on Vcc. Also Pull Ups as I understand their function is to bring the voltage on the pin up a little so that when the transistor in the chip is triggered only slightly the pin will appear digitally to have tripped.

As such what values do you think these resistors should be generally?

If the support is internal, does this mean we still have to place the external resistors?

Thanks to all.

[RFsolution]

I found this solution which was already in the forum, thanks

OK NO NEED FOR THAT

i've attach the latest version... which i thought i had posted here


So the only thing you will have to do, is to add this simple line

DEFINE SCAN_ONCE 1

And this should cure the problem.

I have added this feature once i needed to scan a keypad with a timer interrupt... which is certainly the way to go for any Push-Button/Keypad entry anyways.

Enjoy!

[Darrel Taylor]

This is an update to the PM version of Steve's Matrix Keypad routine.

Steve added a SCAN_ONCE option after I converted it for PM.exe. And someone recently asked for an update to it. It took me so long to do it, I forget who asked.

Note: This is for PM only. It will not work with MPASM.

HTH,