Dashboard wind angle

[mikedefieslife]

I have a strange issue in OpenCPN 4.8.6 and dashboard 1.2

I have a display setup in dashboard to show app wind angle and speed. Data is pulled from my NMEA2000 network via signalk.

The winds speed works well (with a little lag), and the angle is shown as figures in the bottom left corner. At the moment it's -170 degrees.

What doesn't appear to be working is the actual pointer. It consistently points to 0 degrees.

edit: seems my crop of the image missed out the minus sign on the angle, but you get the idea.

[Rasbats]

From ShipDriver and 'sailing' the dashboard shows AWA, TWA.

A copy of the output from the OpenCPN NMEA debugger would be useful to see what sentences your N2K is passing, after translation to NMEA 0183.

Mike

[mikedefieslife]

Here's a snapshot of the debug window.

[Rasbats]

Mike ...

Sentence MWV should have the wind angle:'0 to 360 degrees'.
Your direction is negative which may be why dashboard is not working for direction. First suggestion is to use 'Ignore sentences' for just this sentence and see what OpenCPN does with VWR for wind.

Mike

[mikedefieslife]

MWV isn't on the list of sentences that can be ignored under the sentence filter. I can block it at kplex level, which I've now done.

The problem is I can't test it, as the wind is now at 50 (and mostly comes this way in the marina), it was working, as I suppose MWV was a positive.

Will report back the next time there is a change of wind.

[nohal]

Originally Posted by mikedefieslife

MWV isn't on the list of sentences that can be ignored under the sentence filter. I can block it at kplex level, which I've now done.

The problem is I can't test it, as the wind is now at 50 (and mostly comes this way in the marina), it was working, as I suppose MWV was a positive.

Will report back the next time there is a change of wind.

Mike...

That list contains only the most common sentences as a convenience, you can add anything you want to the blocked sentence list manually (By clicking on the "Add" button next to it).

Pavel

[rgleason]

I wonder if nmeaconverter could be used to block MWV?
I haven't though much about that possibility....however it might be able to.


but better than that, you can ADD any 3character to a filter, why not MWV to a filter?
Look at the output and input filters more carefully.

[nohal]

Originally Posted by rgleason

I wonder if nmeaconverter could be used to block MWV?
I haven't though much about that possibility....however it might be able to.

No. And why would you want it did anything like that? The input connection filter gets rid of it sooner than any plugin ever could.

[rgleason]

Originally Posted by nohal

No. And why would you want it did anything like that? The input connection filter gets rid of it sooner than any plugin ever could.

Agreed, I guess I should have deleted the first idea. Your post beat me to it.

[mikedefieslife]

OK I stopped kplex outputting MWV (why are there two NMEA0183 methods of wind speed/angle anyhow?), and now it seems to work. The pointer displays properly, and the figures read 0-180, then 180-0 as it goes around.

I actually prefer the negative figures for reading wind at a quick glance, but never-mind.

Thanks for the help.

EDIT: one point worth noting is that I could not add MWV to the filters in OpenCPN. I can only select from the list of sentences to allow/block, I cannot type into the input box.

[Tehani]

NMEA 0183 Sentences Not Recommended for New Designs
Approved by the NMEA 0183 Standard Committee as of October 1, 2008:

VWR - Relative (Apparent) Wind Speed and Angle
The use of $--MWV is recommended.

--------------------------------------------------------------------------
NMEA 0183 - Standard For Interfacing Marine Electronic Devices.
Version 3.01
January 1, 2002
MWV - Wind Speed and Angle:

$--MWV,x.x,a,x.x,a,A*hh<CR><LF>
Field 1: Wind angle, 0 to 359 degrees

[Rasbats]

Tehani ...

Agreed ... but the output from Mike's N2K translated to MWV is not in the correct format.

Mike

[Tehani]

Originally Posted by Rasbats

Tehani ...

Agreed ... but the output from Mike's N2K translated to MWV is not in the correct format.

Mike

Yeah sure,
I am thinking where this misinterpretation of the sign can be generated.
- N2k is without sign. The units are in radians. (1e-4)
- In SignalK I see that it is not specified. But since it also uses radians (float), I think it is unlikely that in this first translation a negative sign will be generated because you only have to divide by 10000.

It is possible that the negative sign may appear in the NMEA0183 translation if the angle is averaged to send the sentence at a lower frequency.

Jose Luis

[rgleason]

I don't find MWV sentence in the document...
https://opencpn.org/wiki/dokuwiki/do...nmea_sentences


Shouldn't we have it there? Does Opencpn support the Nmea 3.01 standard?


This question has come up with Tactics_pi too, see Issues in tactics_pi github repository.

[nohal]

Originally Posted by rgleason

I don't find MWV sentence in the document...
https://opencpn.org/wiki/dokuwiki/do...nmea_sentences


Shouldn't we have it there? Does Opencpn support the Nmea 3.01 standard?


This question has come up with Tactics_pi too, see Issues in tactics_pi github repository.

But we do have it there...
https://opencpn.org/wiki/dokuwiki/do...shboard_plugin

Should we duplicate the information from NMEA Revealed beyond listing the sentence? No, that we should not do, unless we can make it well and keep it up to date.