Newb question - RGB Example Problem

[wgm4321]

Two very newbish questions.
If you reduce the delays and leave the RGB example run long enough, it seems to enter a strange state.
I think it's do to this code

Code: [Select]

  int i = 0;
  while(1)
  {
    fade(COLORS[i%3], dir);
    i++;
    dir = !dir;
  }
I think the variable i will eventually overflow going negative.   I changed it to this and it seems to work longer.

Code: [Select]

  int i = 0;
  while(1)
  {
    fade(COLORS[i], dir);
    if (++i > 2) i = 0;
    dir = !dir;
  }
Does this seem correct?
Second question:
Why would you do this:

Code: [Select]

void DigisparkRGBDelay(int ms) {
  while (ms) {
    _delay_ms(1);
    ms--;
  }
}
Instead of this:

Code: [Select]

void DigisparkRGBDelay(int ms) {
    _delay_ms(ms);
}
 Is there some side effect like blocking interrupts or something?
Thanks.

[BStrauss3]

Sure - int is a 16-bit value, +32767 to -32768
So it will wrap to negative, your code fixes that (or you could use a long instead of an int)