RC3 always detects HIGH

[rt_joerg]

Hi,

at the moment I have a problem with the 16F690 I haven’t found a solution in this board.
The 16F690 is used to detect a pulse to ground at nine inputs (RA0, RA1, RA4, RB4, RC1, RC2, RC3, RC4 and RC6). They are all working well but RC3. It always detects a High-Level, regardless whether it has VCC or GND-Level.

I am not using the ADC but reading the ANSEL-Register (ptr = 0x11E; putc(*ptr);) gives a 0x88;

These are my settings:
#fuses INTRC_IO, NOPROTECT, BROWNOUT, NOMCLR, NOCPD, WDT, PUT, NOIESO, NOFCMEN, BROWNOUT_NOSL
#use rs232(BAUD=9600, XMIT=PIN_B7, RCV=PIN_B5, RESTART_WDT, PARITY=E)//, ERRORS)

Does anyone know about this problem and has a hot tip for me?
Many thanks in advance.


BTW: I tried a different PIC. Hence, I can eliminate defect hardware.

[PCM programmer]

Read this thread. It's about RC3 always reading low with the 16F690:
http://www.ccsinfo.com/forum/viewtopic.php?t=26716

If it doesn't help, then try to post a very small test program
that shows the problem. Also post your compiler version.

[rt_joerg]

Thanks for your quick reply.

Following line was missing:
setup_comparator(NC_NC_NC_NC)

With this command the C3 is detecting H/L as expected!

Thanks a lot!