Whoa that is a big rover. Any chance of a photo or video?
Braking isn’t in the Rover code at the moment. Further, your requirement for “standard” braking that people are used to in their cars i.e. a separate brake pedal is different to the braking providing on RC cars where you put the throttle to trim position and a preset amount of braking is applied. Or alternatively when you put a forward moving car into reverse it reverses the current in the motor and causes braking.
So, you can’t do automatic breaking via the Pixhawk at this stage. But you could put your brakes on a separate control on your transmitter i.e. a knob or spare forward stick and apply it like you do a brake in a car when you are slowing down. Does that help at all?
Thanks, Grant.