in my app I have an imageview, its name is arrow and I rotate it of 180 degrees in this way:
arrow.transform = CGAffineTransformMakeRotation(M_PI); >
arrow.transform = CGAffineTransformMakeRotation(M_PI);
To make it return to it's original position, just do this:
arrow.transform = CGAffineTransformMakeRotation(0);
In degrees, 0 radians is 0 degrees, so it should return to its original position.