encoderaudio:
Yes, but as you can see, interval is changed by a pot...As you can see, this should be just an adjustable 0-5V, 7ms pulse generator, where you can adjust the pulsing frequency with the pot.
I've used the BLINK examples as starting point, if there are other, more simple methods, I'm open for them.
But, as you can see, you've introduced a delay into a blink without delay.