[avr-gcc-list] Failing to share a flag between two files/modules :-/

[Vincent Trouilliez]

Hello Gents,

I am having problem communicating between main.c and another
file/module, ui.c to name it.

In main.c I set a flag from a timer ISR, every 100ms. 
In ui.c I am watching for that flag, but unfortunately it always
reads zero :-/ However if I watch for the flag in main() then it works
fine.

I am watching the flag in ui.c, so I declared it in ui.h, then ui.h
gets included in main.c so I can set the flag from there. 
Well that was my reasoning, but doesn't quite work sadly !

I must be doing something wrong obviously, just would love to learn what
it is ! ;-)


Regards,

--
Vince, a bit stuck and wondering again...


ui.h
-----------
static volatile uint8_t flag;



ui.c
----------------

if( flag )
{
   flag = 0;
   /* Do some stuff */
}



main.c
--------
#include "ui.h"

ISR (TIMER0_COMP_vect)
{
        flag = 1;
}

main() {}