Blink without delay, two intervals 240615

For inspiration, maybe take a look at the several different ways of doing Blink Without Delay with multiple LEDs in:

Oops. I meant:

The intervals are different because of this intervals[] array:

That sets intervals[LOW] = 250 and intervals[HIGH] = 2000, through taking advantage of some extra knowledge that LOW = 0 = false and HIGH = 1 = true.