fuuh..now i get it..and thanks DuaneB, now i can get my gyro-servo running..why am i thinking too complicated..hahaha.. 
by the way DuaneB, do you know how do i get this rc hobby gyro hk401b running into AVCS mode? its just only running on rate mode..some says i need to use potentiometer to change its gain..some says i need to set HIGH for AVCS mode and LOW for RATE mode or vice versa..do you have any idea? once again thanks for helping me..sorry im still new with arduino and electronic. =(