ESP8266 Community Forum

Posted: **Thu Mar 23, 2017 7:39 am**

Hi,

I have a problem and I don't really see what is happening.

I want to replace delay() with my own function and use millis().

Here is the code:

Code: Select all

unsigned long returnmilli = 0;
void mydelay(unsigned long foo)
{
  returnmilli = millis()+foo;
  while(returnmilli>=millis())
  {
    delay(1);
  }
}

It's pretty simple, call the function with a number,
the function put the number + millis() into a variable, and does a while loop as long as the millis() is smaller than the variable.

and everything works good,

the problem arrives when I remove the delay(1); inside the while-loop (I did say that I didn't want to use delay - right).

So, I remove the delay() inside the while-loop, and the system crashes immediately when the function is called.

Code: Select all


Soft WDT reset

ctx: cont 
sp: 3fff0980 end: 3fff0be0 offset: 01b0

>>>stack>>>
3fff0b30:  0000001c 00000000 3ffefafc 401004d8  
3fff0b40:  feefeffe 00000001 00000d8a 4020671a  
3fff0b50:  00000000 000000a6 0000000b 4020677c  
3fff0b60:  0000000f 00000011 3ffefafc 3ffefbb8  
3fff0b70:  3fffdad0 00000000 3ffefbb0 402067de  
3fff0b80:  3ffe8440 0000000f 3ffefafc 40207f38  
3fff0b90:  402010ae 0000001e 3ffefafc 40207f5c  
3fff0ba0:  3fffdad0 3ffefafc 3ffef9e4 4020666e  
3fff0bb0:  feefeffe feefeffe feefeffe 3ffefbb8  
3fff0bc0:  3fffdad0 00000000 3ffefbb0 40208634  
3fff0bd0:  feefeffe feefeffe 3ffefbc0 40100718  
<<<stack<<<

 ets Jan  8 2013,rst cause:2, boot mode:(3,6)

load 0x4010f000, len 1384, room 16 
tail 8
chksum 0x2d
csum 0x2d
v09f0c112
~ld
ü


Booting....

I even tried to do some other stuff inside the wile (declare variables, serialprint's and so, but nope, it crashes).

anyone have any clues?

Posted: **Mon Mar 27, 2017 1:21 pm**

I suspect it's because you are using up all the processing power and not even allowing the watchdog timer in. I'm a little surprised that it crashes "immediately"; but then a human "immediately" is a lot longer than a computer "immediately".

Try putting a yield() call in, in place of the delay().

Posted: **Mon Mar 27, 2017 2:50 pm**

arduino on the esp8266 has to return from the main loop every X ms to reset the watchdog.
Only some funtions e.g. delay(), yield() reset the wd, too.
So your delay could work for very small values of foo.

ESP8266 Community Forum

crashing using millis() and while as a delay function

crashing using millis() and while as a delay function

Re: crashing using millis() and while as a delay function

Re: crashing using millis() and while as a delay function