Keypad Interfacing Problems

[new]

I am interfacing a 4x4 matrix keypad with a PIC through the keypad encoder MM74C922. The problem I have is that some keys, when pressed multiple times, would give me different values, and there also seems to be a bouncing issue. I have put a 0.1uF capacitor across the osc pin and 1uF capacitor across the keybounce mask pin on the encoder. I have no idea why this is happening. Please help!

[PCM programmer]

Read the comments in this article about safety and multple inputs:
http://www.geocities.com/dariuskrail20/LCDPad.html

If that doesn't help, then post a short, compilable, test program that
shows the problem. Strip it down to a very small program.

Post a list of the connections between the PIC and the MM74C922.

Post your compiler version.

[new]

Before I extract that part of the code:

I tried not connecting the keypad, and instead, tested it by shorting row/column pins with a wire. This worked without giving me any of the switching-between-numbers or bouncing problems. On the other hand, I tried the keypad with a demo board I used last year and it doesn't seem to be defective.

Does this guarantee that the problem exists in the code?

The thing is that on the old demo board I used a pic16f877, and on this one I'm using a pic18f4523. And I used pretty much the same setup as well as similar code.

[asmboy]

if (similar!=same) result=nul;

[PCM programmer]

If you want help, you need to post a short, compilable test program
that shows the problem. Also post a list of connections between the
PIC and the keypad chip.

[AFAS87]

hi.... i have the same problem.
any one can help

[Guest]

I've used the 74C922 for years (20+,yeesh time flies !)..without any problems. I do connect and test the DV (data valid) pin.
Jay