delay, timer & MEGA board

Using Arduino Programming Questions
1

Hi,
I'm currently face to an issue:
I did recompile the arduino Mega lib, using avr studio, with the following options:
avr-g++
-Wall -Os -fpack-struct -fshort-enums -funsigned-char -funsigned-bitfields -fno-exceptions -mmcu=atmega1280 -DF_CPU=16000000UL

using the created library, it seems that the "standard" delay doesn't work:

from wiring.c

unsigned long micros() {
unsigned long m;
uint8_t oldSREG = SREG, t;

cli();
m = timer0_overflow_count;
#if defined(TCNT0)
t = TCNT0;
#elif defined(TCNT0L)
t = TCNT0L;
#else
#error TIMER 0 not defined
#endif

#ifdef TIFR0
if ((TIFR0 & _BV(TOV0)) && (t < 255))
m++;
#else
if ((TIFR & _BV(TOV0)) && (t < 255))
m++;
#endif

SREG = oldSREG;

return ((m << 8) + t) * (64 / clockCyclesPerMicrosecond());
}

void delay(unsigned long ms)
{
uint16_t start = (uint16_t)micros();

while (ms > 0) {
if (((uint16_t)micros() - start) >= 1000) {
ms--;
start += 1000;
}
}
}

As far as I remember, I already saw a post regarding this, and it was some compiling option that you can see when compiling with arduino tools.

Any link or idea ?
Thanks per advance

2

The cool smiley looks rather good in that code, don't you think ?
Nevertheless, it would help if you were to edit your post and put the code in code tags (# icon above the smileys in the editor)

3

You should never use delay, see blink without delay and then FSM (finite state machines).

Mark

4

Thanks Mark for your hint.
For the moment, as I tried to recompile an existing project, I would avoid to rewrite it.
I will check the options in the makefile, and probably find an issue there.

Samuel