Help With Newguy's Keypad Driver

[jecottrell]

I'm using the driver outlined in Newguy's post:

http://www.ccsinfo.com/forum/viewtopic.php?t=19726

The problem I'm having is that I get a keypress interrupt with both a press and a release. That generates a problem with a number entry routine that I've written. It simply taking the digit entered and multiplying the previous by 10 and adding the new entry. It works great as long as I press and hold the key, but as expected when I release, the previous value is ten times the correct value. (i.e. my character handling routine gets triggered twice for every keypress.)

I have tried modifying the ISR to only detect changes from the "resting state" of portb: 0b11110000, but that causes problems upon the release.

I have considered modifying my character handler to only accept every other entry.... but I have more pride than that.

Is there any easy way to toss out the release interrupts?

Thanks again for all the help,

John

[jecottrell]

I think I've got a solution but I think I may have a hardware problem.

When I press and hold the switch on B0/B4 the LCD constantly refreshes. I have confirmed with LED flashes that the ISR and the "if keypressed" routines are not firing with the pushbutton held down.

BTW LCD is on port D.

Any help or suggestions would be greatly appreciated.

John

[jecottrell]

I found the source of the problem(s) and a solution to the "interrupt on key release" problem.

To only register the keypress and not the release modify the ISR as follows:

[William H. Conley III]

It must suck having to talk to your self....

- Red Helmet Out
_________________
- Bill

[Bart]

Thats a nice remark !!
_________________
I like Skype (www.skype.com), my username is BplotM