FlxTween can be used to change values over time following a number of available curve functions.
Using angle allows you to change the angle of a FlxSprite over time.
// create an angle tween
FlxTween.angle(myObject, fromAngle, toAngle, duration, {type: tweenType, easing: FlxEase: easeFunction});
package;
import flixel.FlxSprite;
import flixel.FlxState;
import flixel.tweens.FlxEase;
import flixel.tweens.FlxTween;
class PlayState extends FlxState
{
var sprite:FlxSprite;
override function create()
{
super.create();
sprite = new FlxSprite("assets/arrow.png");
sprite.screenCenter();
add(sprite);
FlxTween.angle(sprite, 0, 180, 1, {type: FlxTweenType.PINGPONG, ease: FlxEase.backInOut});
}
}