Navigate from waypoint to waypoint (Trig fun)!!!

[Chad_Peddy]

I am automating my boat with Labivew, in Alameda Ca)

I receive GPS data via bluetooth (Garmin Glo)

I communicate with my autopilot via NMEA communicated via TCP (Comar i320W)

Currently I just send heading data, and the autopilot changes to that heading.

Fun Times!!

Now I wish to tell it to go to a "waypoint" (Lat and long on an xy grid)

this takes high end trig that I forgot pre covid.

Any thoughts?

[GerdW]

Hi Chad,

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@Chad_Peddy wrote:

this takes high end trig that I forgot pre covid.

Any thoughts?

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Get a book on basic math (including trigonometry) - read and learn.

Then setup the formulas to convert from position/distance to heading/speed parameters…

(I don't think this will be "high end trigonometry"…)

[Bob_Schor]

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@Chad_Peddy wrote:

Now I wish to tell it to go to a "waypoint" (Lat and long on an xy grid)

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My first thought is that Latitude and Longitude are not coordinates on an XY (planar) grid, but are coordinates on a spherical surface.  Makes it an even more fun math problem, as the shortest distance between two points is part of a Great Circle whose center coincides with the center of the Earth (if I remember my math correctly ...).  I suspect that Spherical Polar coordinates are going to be involved sooner or later.

Bob Schor

[Chad_Peddy]

Thank you, your input is valuable