If I understand your question correctly, you want to trigger another plot on your drone when your drone reaches a certain lat and long position automatically without flipping the flight mode switch to Auto?
Theoretically yes, practically not sure :)
Let me get creative here and suggest an alternative way to do what you wan to do. But, are you familiar with Mission planner flight mode feature? if not you need to get familiar with it for this to work.
In layman terms on your radio Tx when you send a command to Pixhawk to go into "Auto" mode, regardless where the drone is in the air, it will go to the starting point that you predefined in mission planner way point, which you have already uploaded into the pixhawk. Once it reaches its predefined starting point (you can set, height, speed etc. etc. in advance), it will to predefined paths.
Run Mission Planner, go to "Flight Plan" tab, create a fake Flight plan, and save the file so you can view it later.
PixHawk is looking for command
You can watch this video I just uploaded Video
In your software what you need to do is as follows:
1. Your software that monitors the current location of the drone will use the predefined lat and long positions (which are basically the way point starting point prestored in PixHawk) as the software trigger to kick in the Auto Mode. I would give your program +/- 5% lat long tolerance as GPS used on drones are not military standards, so there is always a margin of error.
Once your program see the defined lat long values within defined range, all you need to do is tell PixHawk via software command, inside the PixHawk controller, to go into auto mode.
Simple solution! Conceptually it should wok, however I am not sure inside PixHawk if you can run two routines simultaneously unless there is another block where you can store your program and it doesn't impacts the way point data and other processing power of Pixhawk.
Let me know if this works. if it does, I want a copy of your program :)
p.s Looks like final Engineering program thesis to me :)))
here is screen shot of Flight mode parameters.
Well I am a rookie when it comes to programming PixHawk directly as I am just beginning to get my hands dirty, but we can learn it together :)
Ardu pilot is comprised of libraries which you can call from your program. First check this Link
So the library you need to tap into is called AP_WPNav - waypoint navigation library and the other one for you need would be the AP_GPS - gps interface library
Your starting point to learn coding Pixhawk is to read all these documentations. Pain in the neck Learning the ArduPilot Codebase. Keep in mind all these documentations are dated to some degree but its a start.
I honestly wish if someone offers a training class on Ardu pilot coding. I would take it in a heart beat.
Ground station use MAVlink protocol to send messages via a 915Mhz TX/Rx to PixHawk or through a direct USB cable.
As long as your done is within telemetry range, for what you are trying to accomplish i think will be easier that you run your program on a lap top, use telemetry to receive GPS Co-ordinates as your trigger, and send Auto mode signal via TX to the drone. This way you don't have to mess with PixHawk programming altogether.
I am sure there are people on this site who have done all this before. May be someone else can chime in here.
Check out this thread..Link
Red this page. It will give you the history. They are just different versions of PixHawk. Pixhawk is the latest Flight controller.
AND MAKE SURE YOU HELP OTHERS when you learn a thing or two. I am surprised to see so many people view and read questions posted by people and very few volunteer to help. Not good :(
To answer the question, yes GCSs are scriptable. Here's how to script Mission Planner with Python: