Help / FAQ

[Larry]

Thomas
Thanks for the help. I compiled the latest git and like you said it is working well.
Great work on the program. I am very pleased to be able to navigate in Linux rather than have to wrestle with Windows.
Thanks for all your hard work. I will be back on the water in about a month and try and give feedback.
Cheers
Larry

[doug86]

I am running 2.1.0 on a Windows machine using a BU-353 USB GPS. All works well, and I like the latest version of OpenCPN very much... but...

The BU-353 seems to send COG and speed data too fast, and OpenCPN can't quite keep up, so that I never see a good average speed, and the heading indicator jumps around a bit. I had an older USB GPS for some time that didn't do this, but that unit died.

Is there a way to adjust the data flow so that OpenCPN doesn't update so often? The charts get really jumpy when my boat is sitting still, especially in Look Forward mode. Most software has a way to dampen the data and allow it to average out over a set period of time. Does OpenCPN have any way to do this?

thanks for a great program

[cagney]

doug86

Is there a way to adjust the data flow so that OpenCPN doesn't update so often? The charts get really jumpy when my boat is sitting still, especially in Look Forward mode.

At least part of what you are asking for is scheduled for the next stable release, and is already implemented in the latest beta 2.2.1026.
On this page Auto Follow and Display Orientation | Official OpenCPN Homepage a few paragraphs down, this feature is described:

Don't always Look Ahead! If you are at anchor, swinging on the hook produces random courses and low speeds.If Look Ahead is on in this situation the chart rendering will constantly be redrawn, with the boat in all possible lookahead positions as the course changes. To prevent this kind of scenario OpenCPN works like this:
*If the boat speed is less than 1 kt, then lookahead is disabled.
*If boat speed is greater than 3 kts, lookahead is enabled.
*In between 1 and 3 kts, the lookahead "distance" is adjusted smoothly.

Thomas

[doug86]

thanks Thomas. I have been just turning off Look Ahead when I'm going slow or standing still. The new feature will even save that small effort. But the bigger issue remains, that of OpenCPN updating too frequently. Perhaps I don't understand the technology; is the COG generated by the GPS, or does OpenCPN calculate it? In most plotters that I have used, there is a "dampening" setting to smooth out the data.

The documentation for the GPS doesn't suggest any way to adjust or change anything, so I was hoping there was a way with the Opencpn.

[cagney]

I have checked "Flyspray" OpenCPNs tracker for a feature request in line with your request. OpenCPN::Tracker OpenCPN - Feature Requests: Tasklist I failed to find one, which is surprising, as this is not the first time this subject pops up.
doug86, why don't you go ahead and enter a feature request??

As I understand things, the BU 353 calculates the speed and sends it to OpenCPN in the NMEA0183 data stream. Some higher end Gps:es probably have built in dampening functions. Cheap and versatile gps:es similar to BU 353(gps mouse) are very popular and it's a reasonable request that OpenCPN develops a user configurable dampening for gps:es that lacks this feature.

Thomas

[fgd3]

Originally Posted by doug86

The charts get really jumpy when my boat is sitting still, especially in Look Forward mode.

The easy workaround for that is to turn off "auto follow" when your boat is sitting still. The "own boat" icon might still jump around, but the charts will be stable.

Fabbian

[fgd3]

Maybe I've missed it, but one of the justifications for replacing raster charts with vector charts was that the chart plotting software could be cognizant of your draft and give you a warning if a proposed route crosses a shoal. Is there such a facility in OpenCPN?

Fabbian

[sailias]

Under Tools > >Vector Charts > set depth should work. Enhoy

/ch

[fgd3]

Originally Posted by sailias

Under Tools > >Vector Charts > set depth should work. Enhoy

/ch

There's no "Set depth" option there. There are fields for entering shallow depth, safety depth, and deep depth. Those settings affect the color on the rendered charts, but there is nothing I have found that issues a warning if a proposed route crosses an area that is less than any of those depths.

Fabbian

[Netsurfer]

Fabbian ...

Originally Posted by fgd3

... but there is nothing I have found that issues a warning if a proposed route crosses an area that is less than any of those depths.

AFAIK there is no such feature in OCPN, yet.

As this might be a helpful (safety) feature feel free to add a feature request for it to the tracker - thanks!

Gunther

[fgd3]

Originally Posted by Netsurfer

Fabbian ...

AFAIK there is no such feature in OCPN, yet.

As this might be a helpful (safety) feature feel free to add a feature request for it to the tracker - thanks!

Gunther

I will. I just wanted to be sure it wasn't already covered before adding it to the list.

Fabbian

[bvimatelot]

Hi there and I apologise if I'm in the wrong section of Open Cpn!

I'm on Win 7 64 bit and Open Cpn 2.1.0 build 624a. All is well (actually, extremely well!) except just this last week I lost grib functionality. I have the grib icon ok but now when I click it - nothing happens. I had downloaded grib.usa files and they've always been fine up to last week.

Tried to open "Help" but it appears that you have to be online. So I couldnt help myself 300 miles South of Bermuda! Am I missing something in order to have the help pages available?

Finally - Can I get a lat/long grid on CM93 (or indeed any other) charts? Not critical, but I like it!

Many thanks, Tony

[cagney]

bvimatelot

You do not have to be online to get help. Just don't click any links. Scroll down the (big) page and all the content will be there.

If you are online and click the links you end up in the wiki on opencpn.org, which describes recent beta releases.

This bug will be corrected in the next stable release.

Thomas

[dirtybottom]

Hello - I am new to this forum and just loaded OpenCPN.

I looked for a previous post on this but only found people who were able to use their 18x with win XP but not with 7. Well, sadly I am unable to use my 18x with win XP. Garmin requires Spanner for USB -> Serial and I used that. I was able to see the NMEA data stream but was unable to Auto Follow. I was able to get my Garmin 72H to work completely but not my GPS 18x USB.
Any help would be appreciated.

[Extemporaneous]

Originally Posted by dirtybottom

Hello - I am new to this forum and just loaded OpenCPN.

I looked for a previous post on this but only found people who were able to use their 18x with win XP but not with 7. Well, sadly I am unable to use my 18x with win XP. Garmin requires Spanner for USB -> Serial and I used that. I was able to see the NMEA data stream but was unable to Auto Follow. I was able to get my Garmin 72H to work completely but not my GPS 18x USB.
Any help would be appreciated.

1. Welcome aboard!
2. Sorry can't help you!
3. Your name made me chuckle.
4. Stay away from me ;-)

Cheers,
Extemp.