PIC16F676 Won't Run

John676 · Guest

Hi. I have tried a simple program with CCS PIC C that is supposed to turn on some LEDs, but it wont run. I know the pic works because I compiled the program in both Pic BASIC and in MPLAB and there were no problems there.

I think its got something to do with the configuration bits (or fuses as they are called in Pic C). I am setting the exact same fuses in MPLAB, so not sure what the problem is.

Here is the code:

#include <16F676.h>

#fuses INTRC_IO // Internal RC osc, no clock out

void main()
{

set_tris_a(0); // Make all outputs
set_tris_c(0);

OUTPUT_A(0xff); // Set all pins - turn on LED's
output_c(0xff);

}

I have also tried using the FAST_IO to set the data direction registers, but that didn't make any difference.

Thanks in advance for the help.

Regards,

John

PhilWinder · Joined: 16 Apr 2005 Posts: 23

I know how you feel, I hate these stupid, "why wont it start" problems. Could be a number of things,
Put in all the fuses in PICC, because every time you re-import your file in MPLAB, the HEX file will overwrite them. Better to just make sure there right by checking once, then forget about it.
I dont know about the chip you are useing, but the Comparator, A/d etc. have not been disabled.

So for an example, your file should have something like:

John676 · Guest

Hi Phil.
Thanks for the suggestions, I tried them but alas, no joy. I've tried just about everything I can think of, even different clock speed settings.

Nothing seems to work. I wonder if there is not some problem with CCS's pin assignments for this pic.

Thanks,

John

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

rnielsen · Joined: 23 Sep 2003 Posts: 852 Location: Utah

Make sure you have a while(1) in your main so the program doesn't fall off the end and make the PIC fall asleep.

Ronald