So I have an existing airframe which has a servo for the rudder and a servo for the nose gear steering. Usually in RC I just combine the actions in the controller. Is there a way to have one of the aux channels on the ardu be a nose gear steering channel so that during landing roll out it would steer the aircraft? If not I can just skip the ardu and always land manually.
Well, if you are used to combining the actions, why not continue to do so? Get a Y-cable and connect the aileron (or rudder) output to both the aero surface and the nose wheel?
Sorry there may be some confusion. I usually have a channel for rudder and a channel for the gear. In the radio Tx I setup that the gear is a slave to the master rudder. This allows me to trim the rudder in flight and not affect the trim on the steering. This is really convenient and there are no YCables. During manual control the ardu should be passing through the commands and therefore should operate the same. But during autonomous operations how would I setup the same master-slave I have in the radio. Again this is so that during a auto landing the nose gear would operate.
The simple fix is a ycable, but where is the challenge in that. Plus you can no longer trim out the steering seperate from the rudder.