Hi, I conected a servo sg90 black wier to grand on arduino the red wier to 5v and the yellow wier to pin 9, very simple, I up loud the strch that is in the demo and nating, the servo don't move, what cen I do?
I think you're trying to say "I connected a servo sg90 black wire to ground on arduino the red wire to 5v and the yellow wire to pin 9, very simple. I uploaded the sketch that is in the demo and nothing, the servo doesn't move. What can I do?"
If that's right then you need to post the sketch here. We don't know what demo or sketch you're talking about. If by any chance it is the standard Sweep example then that always works so you've probably connected something wrong or the servo is bad.