Change waypoint position in OpenCPN from remote application

[atlet]

Hi,
I have made a kayak drone with electric propulsion that automatically steers towards the active waypoint in OpenCPN. It basically follows the route set up in OpenCPN. Now I want the drone to follow a moving object. If I can send a new position for an existing waypoint to OpenCPN, I do not need to make any changes to the drone's control system.
Does anybody know a way to alter a waypoint in OpenCPN from an external program?

atlet

[stevead]

One way would be to write a simple plugin that uses the OpenCPN API's

AddSingleWaypoint(PlugIn_Waypoint *waypoint, bool permament);
GetSingleWaypoint(wxString guid, PlugIn_Waypoint *waypoint);
UpdateSingleWaypoint(PlugIn_Waypoint *waypoint)

to create, retrieve and update a waypoint.

In your plugin you would need to maintain some sort of reference to the waypoint guid and of course your plugin would need some form of communications to the outside world , limited by only your requirements, imagination and programming skills.

The only caveat I have, is I have no idea whether OpenCPN adjusts it's active route if a waypoint's properties (esp. Lat & Long) are changed mid-way.

[atlet]

Thanks a lot! I will try to see if this could be a way forward. Have not previously written any OpenCPN API, so I have to look into that first

[Rasbats]

atlet ...

Using ShipDriver in AutoPilot mode I can move the waypoint. It becomes inactive and then when it is activated again the autopilot finds the new waypoint and steers towards it.

Interesting stuff you are working with. Have you published any code?

Mike

[atlet]

Hi Mike,
Thanks for the feedback. No, I have not published any code. My control software is rather simple as I let OpenCPN do most of the navigational tasks. The control software only reads a few output telegrams from OpenCPN and based on those it controls throttle and the small rudder motor. If I had attempted to make a control application that included a chart and all the other stuff available in OpenCPN, it would have been a huge task and the result would have been very poor.