why do i hafta go around in circles? i can't use delay or delay_ms or ellapsedmilis because all three timers are busy and can't be interrupted.
but this:
for (t = 0; t<10000; t++){ for (x = 0; x<10000; x++){} }
shouldn't be a nightmare. but nooooooooo, gcc won't stand for it.
so there's this file, C:\Program Files (x86)\Arduino\hardware\arduino\avr\platform.txt, that supposedly i can edit and tell gcc to getthehelloutamyway!

and it has this paragraph:
# Default "compiler.path" is correct, change only if you want to override the initial value
compiler.c.flags=-c -g -Os {compiler.warning_flags} -std=gnu11 -ffunction-sections -fdata-sections -MMD -flto -fno-fat-lto-objects
compiler.c.elf.flags={compiler.warning_flags} -Os -flto -fuse-linker-plugin -Wl,--gc-sections
compiler.cpp.flags=-c -g -Os {compiler.warning_flags} -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -MMD
compiler.objcopy.eep.flags=-O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0
compiler.elf2hex.flags=-O ihex -R .eeprom
where the -O option appears no less than 5 times. can someone who speaks gcc tell me what to do here?

thanx, CrazyInLA

 

What does the compiler say? The nested 'for' loops just use a lot of processor time to create a delay, correct? You should declare your loop counter variables as integers. Perhaps the syntax should be:


for(int t = 0; t<10000; t++){
for(int x = 0; x<10000; x++){
}
}

 

yes they are unsigned integers. the problem is that the compiler is configured to "optimize" the code for faster execution. it sees those statements and goes "he's wasting time. i'll modify the code so that no matter what #s he uses for x or t, i'll minimize the time delay"
and that's what i see. whatever #s i use i still get a delay of about 100ms.
but now i may have a solution. somebody over at http://www.electro-tech-online.com/threads/pwm-problem-cant-set-duty-cycle.149671/#post-1283925 electrotech online said that i could create an interrupt routine that will execute every time the timer overflows that will increment a variable. this will not interfere with the timer and will give me a way to create a delay. unless of course the compiler gives me <snipped language> about that, too.

 

Is this of any help

http://stackoverflow.com/questions/2219829/how-to-prevent-gcc-optimizing-some-statements-in-c

Look for:

#pragma GCC push_options
#pragma GCC optimize ("O0")

your code

#pragma GCC pop_options

About half way down

 

How much delay do you need? A 555 timer could trigger an interrupt too.

 

Is this of any help
http://stackoverflow.com/questions/2219829/how-to-prevent-gcc-optimizing-some-statements-in-c

BINGO!
there were several answers on that page and the simplest one appeared to be this:
void __attribute__((optimize("O0"))) functionName()
{
}
and that did it the O0 only applies to that function. many thanks....

 

Cool, no probs bro.

 

How much delay do you need? A 555 timer could trigger an interrupt too.

there's always that. i actually used a 555 on a design last year. they will never go out of style. but i got many delays in my code of different duration.
thanx

 

Go have a peek at what the "volatile" keyword does.

Hint: it tells the compiler don't assume you know what value is in that variable.

Hint 2: it is transportable between compilers.

 

Go have a peek at what the "volatile" keyword does.
Hint: it tells the compiler don't assume you know what value is in that variable.
Hint 2: it is transportable between compilers.

hmmm.... i never thoughta that. that's even simpler. thanx i'll try it