AVR-Chat

Thanks Brain for the suggestion. I did that and AVR Studio is still
messed up. 


-----Original Message-----
From: Brian Dean [mailto:bsd@bdmicro.com] 
Sent: Tuesday, April 12, 2005 1:18 AM
To: AVR-Chat@yahoogroups.com
Subject: Re: [AVR-Chat] Strcmp() problem stepping through AVR Studio



On Sun, Apr 10, 2005 at 10:51:01PM -0400, wbounce wrote:

> If have serveral strcmp statements
> 
> Originally I had them all like this.
> 
> if (strcmp("GPGGA",gcBuffer) == 0)
>       {
>       gpFieldPtr=(PGM_P) GGA;
>       }      
> 
> It would execute the pointer assignment on each of the 8 statements
> 
> I changed them to
> 
> lnResult = strcmp("GPGLL",gcBuffer);
> if (lnResult == 0)
>       {
>       gpFieldPtr=GLL;
>       }
> 
> So I could see the result code of strcmp. This time it skipped the 1st

> 3 ok but then started doing the assignments. And when it got to the 
> strcmp that should have matched, lnResult was not 0 and yet it did the

> assignment anyhow.
> 
> Anyone have any idea why?

I'm not sure about the problem, but just a quick observation.  With
AVR-GCC, string references like above consume both Flash as well as
precious RAM.  It can add up quickly, too.  To rewrite those to save RAM
space, try:

    strcmp_P(PSTR("GPGLL"),gcBuffer);

This references the string data directly from Flash and saves making a
copy of it to RAM.

-Brian
-- 
Brian Dean
BDMICRO - ATmega128 Based MAVRIC Controllers http://www.bdmicro.com/


 
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