We had some discussion on last Camera Working Group meeting on what system_id should be used by a daemon running on a companion board and that communicates with QGC using same communication channel. Should we use same system id that is used by the flight stack or should we use a different system id?
This is a question regarding the meaning of system_id. A system id should identify a Vehicle or a node that is communicating using MAVLink?
In my specific case, we have a flight controller and a Camera daemon running on a companion board. We have a piece of software that is in charge of routing messages that are directed to the vehicle to the correct component. It was commented that in this case we should use the same system id in the flight controller and the camera daemon, because QGC considers that different system ids are different vehicles, but in my understanding, we should have different system ids.
So, any opinions about that? Is there any well defined case that is similar to the case I am describing and that have a well defined solution?
From a QGC standpoint a system_id equates to a vehicle. Component ids can then identify different components within that vehicle. If you use a different system id to identify say a camera that is on a vehicle how does a ground station have any idea that camera is associated with which vehicle?
@lucasdemarchi you have commented that you have seen some use cases where a vehicle have multiple components with different system id. What is your opinion about that question?
@LorenzMeier @dogmaphobic @JulianOes Would you guys like to comment on this. It would be helpful to come across a precedent where one or more of the component of the Vehicle was running in the companion board and how sysid/compid were managed in that system.