Hello, For the sake of better understanding APM guts I've been working on what I've been calling ArduGimbal.  I've just assembled code together looking at Arducopter 2.5.5 for how to structure the code and Arduino AHRS example & Compass example code to get heading and attitude.  I'm using an APM2. I've made a triple axis gimbal out of a Hobbyking gimbal, a prop balancer and the main rotor g…