OpenCPN Version 4.0 Released

[George64]

thank Pavel. Will upgrade to v4.0

[rgleason]

Yes, 4.0 is much better! Upgrade.

[Wurm]

My first post on this forum, my background is in coastal sailing, and for navigation purposes I have only used paper charts and a Garmin GPS that I bought in 2001 with a small chart screen.

I have just downloaded version 4.0 and a chart from the NOAA ENC list. However when I try to upload the chart using the plugin I get the error message:

Security Scheme Error

SSE 10 = Permits not available for this data provider

Since it is a NOAA chart I would have thought permits would not be an issue. I have searched this entire site and not found any prior discussion, so any help would be appreciated.

[nohal]

Wurm...
You are trying to use the S63 plugin with the free, unencrypted, charts. Not needed at all as you correctly assume. Just read Installing Charts | Official OpenCPN Homepage to use the stuff you download from NOAA. Or get the Chart Downloader plugin to make you chart management easier.

Pavel

[Wurm]

My first mistake was to upload a folder 'too high' rather than the root folder, and the second was to install the wrong chart downloader, but I think I have now just downloaded the NY charts although there doesn't seem to be much detail in the Hudson.

Is there any reason not to download the whole NOAA ENC database? I've got 100GB to spare on my hard drive.

[nohal]

Wurm...
If you don't mind the space and time to download, get whichever unneeded charts you like...
FWIW the detail of both the RNC and ENC NOAA charts for Hudson in NY is just what I would expect.

Pavel

[bdbcat]

Pavel...

Also, FWIW, I find that the information content of "old-fashioned" RNCs is vastly greater than modern ENCs. These two screenshots are perfect examples. It is not always true that ENCs are "better" in any real way.

Thanks
Dave

[RhythmDoctor]

Guys,

I've been using 4.0.0 since it came out, and loving it. Really stable version - great job! I've been busy changing jobs lately and spending what little time I have actually sailing. Thus I haven't been able to do the kind of "abuse testing" of OpenCPN betas that I normally do.

But in my normal use of 4.0.0 on my boat, I have noticed one problem vs. 3.3.???? that I was using last season. In my setup (Win8.1 tablet) I have GPS data coming in on COM3, and I also have autopilot data (VTG,ECRMB,ECAPB) going out COM3 to my autopilot's NMEA input. This allows the autopilot to operate in "Track mode" and also allows me to display XTE, SOG, and other data on the Autopilot's control panel.

This issue is with the Autopilot's display of SOG data. Within OpenCPN's dashboard plugin, SOG is very stable, predictable, and correlates well with my own visual observation (it goes up when the boat speeds up, goes down when the boat slows down, etc.). When running 3.2.2, the SOG displayed on the autopilot agrees well with the OpenCPN dashboard. It doesn't agree exactly, but it's very close. The differences are easily explained by an apparent time-averaging algorithm, since the two values move in the same direction, just at slightly different rates. It was very reliable.

But when running 4.0.0 to send the NMEA data to the autopilot, the values displayed on the autopilot are crazy and in wild disagreement. I can see the boat slow down from 5 knots to 4 knots (with dashboard as well as my own eyes), but the autopilot may continue going up to 5.7 for several seconds before starting to drop. And by the time it's dropping, a puff may have come up to speed up the boat, but the autopilot does not register it nearly fast enough. The values are so far off that SOG display on the autopilot is basically worthless.

And the issue is more than cosmetic. An incorrect SOG can cause the autopilot to go unstable, since its control logic automatically adjusts the rudder sensitivity based on SOG. So if it thinks that the boat is going 2 knots but it's actually going 5, it could oversteer and cause growing oscillations in the heading.

So my question is whether you guys did any changes in the damping algorithms for 4.0.0 that would affect the NMEA sentences going out to the autopilot in a different way from the 3.3 betas. Because I'm definitely seeing a difference.

[bdbcat]

RD...

Welcome back.

Funny stuff with A/P SOG....

We filter SOG and COG according to the time constant set in options->Connections. The idea is to "soften" the data for some fussy autopilots.

If you set the constant to "1", there is no effective filtering.

Thanks
Dave

[RhythmDoctor]

Originally Posted by bdbcat

RD...

Welcome back.

Funny stuff with A/P SOG....

We filter SOG and COG according to the time constant set in options->Connections. The idea is to "soften" the data for some fussy autopilots.

If you set the constant to "1", there is no effective filtering.

Thanks
Dave

Yes, I figured that's what that parameter is for. I tried numerous values and could see the effect in the dashboard SOG value. Higher time meant more damping and less volatility in the value. But the autopilot was still doing wacky stuff at virtually all values. I don't have specific description of the values that I tried. I typically use 2 seconds, but tried higher and lower over the last couple of months and have never gotten good agreement between dashboard and the autopilot display.

[bdbcat]

RD...

So, we will need to get a look at the ACTUAL DATA going to the A/P.

A snapshot of the NMEA debug window might show some divergence between the SOG as received from GPS and the SOG sent out to the A/P.

Lets start there...

Dave

[RhythmDoctor]

Originally Posted by bdbcat

RD...

So, we will need to get a look at the ACTUAL DATA going to the A/P.

A snapshot of the NMEA debug window might show some divergence between the SOG as received from GPS and the SOG sent out to the A/P.

Lets start there...

Dave

I had already tried a variant of this in my home. I ran two instances of OpenCPN, with VDR playback in one with data going out to localhost via UDP, and VDR recording the UDP input on the other. I then loaded both VDR files into Excel, filtered out everything but the VTG sentences. I parsed the data into columns and put the two SOG columns next to each other. They were exactly the same. Not even any evidence of any time lag or other damping between the two.

Of course, with autopilot, the VTG data goes out to COM3, not UDP. Also, it's possible that real-time data is treated differently from VDR recorded data. But both of these are unlikely scenarios. So I'm stumped.

To get better a handle on this, I'll have to go back down to the boat and feed the data into the autopilot like you suggested. I'll first try to play VDR data at the dock and see what the autopilot shows. If it looks funny, I'll get video of the two displays side-by-side, and also try to do a screengrab of the NMEA debug stream.

I'll also try to resurrect my 3.3 beta install to compare the result.

Unfortunately I'm traveling for the next several days, so it's doubtful that I'll make it to the boat today. So it may have to wait for awhile.

[Wurm]

Originally Posted by bdbcat

Also, FWIW, I find that the information content of "old-fashioned" RNCs is vastly greater than modern ENCs. These two screenshots are perfect examples. It is not always true that ENCs are "better" in any real way.

Dave

With just the ENCs I was getting no depth soundings at all in the Hudson even at maximum zoom, but with the RNCs the detail looks good.

What don't appear to available for download on either the NOAA or the ACE list are charts for the Erie Canal and Hudson north of Troy, does anybody know of a source?

This is remarkable for free software.

[INTP]

RE: Erie Canal
NOAA site has what your looking for.

Interactive Catalog

I think downloading all charts for New York State would be the easiest.

Chart Downloader for NOAA RNC&#174

and

Chart Downloader for NOAA ENC®

[Wurm]

Originally Posted by INTP

RE: Erie Canal
NOAA site has what your looking for.

Interactive Catalog

I think downloading all charts for New York State would be the easiest.

Chart Downloader for NOAA RNC&#174

and

Chart Downloader for NOAA ENC®

There is a bug in OpenCPN in that I downloaded the whole of NY through the plugin but many of the charts in those links were not featured. Thanks for the reply, I will do them by hand over the next few days.

The procedures for reporting the bug on the OpenCPN site appear to be quite cumbersome.