I'm working with the Pixhawk right now and I'm wondering where the standard frame controllers are stored in the PX4 Firmware code. What I'm trying to do is set out a custom mission with my own additions, but I don't want to rewrite all the controllers that have already been defined. For example, one of the components of my mission involve using a quadcopter configuration. Nonetheless, it appears to me that use of the PX4 standard frame is exclusively in manual mode, which means that when I flip the switch to mission, I'm running my own controllers (please tell me if that's not the case). Since PX4 has already done a lot of the controls work, I thought it'd be most efficient if I borrow their stability controller in my mission code, i.e. their middleware.
That said, does anyone know where the controls code for the standard frame is kept and how I could best use it?