PIC16F914 input on unused VLCD pin C2

[Birdie]

Hello All,
I am using PCWH 3.235 and a PIC16F914 with a static drive LCD.
I have connected a N/O pushbutton and pull-up resistor to the RC2/VLCD3 pin; when the pushbutton closes RC2 sees ground.
The problem: when I push the button the LCD segments go completely blank.
When I release the button the segments are normal.
The compiler creates this:

[PCM programmer]

The setup_lcd(STATIC) code appears to be correct. It is disabling
the LCD bias voltage, so pin C2 should be a normal i/o pin.


What code is being executed after the if statement ?
if(input(PIN_C2) == 0)

You don't have to post the ASM code. Just post the C code.

[Birdie]

Thanks for the response.

It makes no difference what the code is, or even if there is code; if the pin gets grounded, the LCD goes blank. I am going to try to switch the wiring so the pushbutton is on a different (not VLCD) I/O pin.

I'll post the results.

Thanks again.

[Birdie]

Well I managed to swap pins and get the LCD to work when the button is pressed.
It seems that the VLCD3/RC2 pin will cause the LCD to blank if brought to logic 0 (either by hardware {push button} or by code!
I wonder if there is some setup I'm missing.
Neither VLCD2 nor VLCD1 cause the LCD to blank, only VLCD3.

[adrian]

Have a look at this post from the Microchip forum..
http://forum.microchip.com/tm.asp?m=114122&mpage=1&key=lcd&anchor#114144