Rapidly spinning laser to create one-lined image

[quote author=Runaway Pancake link=topic=105616.msg793298#msg793298 date=1336944454]
It was in a blinking application of sorts, a "low" frequency with a narrow pulse "on" (low duty) - a great success.

[/quote]What was the actual reason why you couldn't you just use a digi out pin and the appropriate resistor to switch the laser on and off? What would've been the result if you tried to do it the way I just described?