Chart orientation switching

[mcm]

Noticed something odd today, am on land doing some planning charts on screen normal layout of north /south .
enabled gps and everything went south/north orientation , disabled gps and reverse happened.
So I thought that my setting of course up in nav mode was doing that but surely the orientation is always supposed to be north/south regardless of nav mode which should only come into effect when in motion ?

also noticed scroll speed dropped dramatically ?

[bcn]

What does your NMEA debug window show?

[mcm]

seems all ok..see screen shot.

[Dsanduril]

You can set OpenCPN to "north up" or "course up". If set to course up it takes the data on your course from the GPS and uses that to decide what "up" should be. Looking at the status bar, your GPS it telling OpenCPN that your COG is 180, so that's what OpenCPN uses. It will likely be very jumpy. The GPS computes COG from two (or more) position fixes, as frequently as 5 or 10 times a second. Since you are sitting still the differences in position are just the noise in the signal, and so your COG will likely jump all over the place.

This could possibly also explain the slow scrolling, if your COG is changing all over the place then a lot of processing is going to deciding how to display the charts. In this scenario a fixed "north up" display is better. There are other possible reasons, but that's where I'd start.

[mcm]

So, course setting in nav mode activates upon gps activation even though the vessel is static ? So, if I leave the mode as north up then when underway switch to course up should alleviate any of the aforementioned issues ? or course up stays on and enable gps on getting underway ? BTW, using ver 5.2.4

Tks for the clarification.

[Dsanduril]

Yes. As soon as OpenCPN starts to receive course information it uses it to set "up" when in course up mode. IIRC there is a setting someplace to tell it how frequently to decide what "up" is, but I don't have that in front of me at the moment. Doesn't really matter how fast you are going, as long as there is a course....

You could do it either way. My personal preference is to switch between "north up" and "course up" as needed, I like having my GPS available when not moving (for instance, when using the anchor alarm as one example).

[nohal]

If you are moving, your GPS starts reporting COG that makes sense and the course up chart orientation starts to make sense as well.

If you are not moving and have GPS connected and producing nonsense COG data, course up makes no sense and "issues" like what you mention are more than likely to happen.

Without GPS connected, all the chart orientation modes look like north up as there is no course information coming from anywhere.

Switching between chart orientation modes can be performed any time by single clicks on the small GPS toolbar in the top right corner of the OpenCPN window.

Do not use course up mode when you are not moving. Course up mode is also extremely unpractical for route planning in my personal opinion, moving or not.

[mcm]

All clear, a bit different from my other prog, which I have used since 1994 in the pnw but it's time to retire that one, getting too goofy with crazy "improvements" .

Thanks again guys...