Dashboard wind angle

[Tehani]

Originally Posted by nohal

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.

I think it's fine like that.
It is not about duplicating information. It is about exposing what sentences O processes.

[nohal]

We do expose what sentences OpenCPN processes, including the now discussed MWV.
We do not need to duplicate the detailed information about their structure, that information is maintained elsewhere, in a completely sufficient way and all we need is reference the source of the information.
We do not have the manpower, and there is no need, to maintain a copy of the information, especially with zero added value.

[Tehani]

Originally Posted by nohal

We do expose what sentences OpenCPN processes, including the now discussed MWV.
We do not need to duplicate the detailed information about their structure, that information is maintained elsewhere, in a completely sufficient way and all we need is reference the source of the information.
We do not have the manpower, and there is no need, to maintain a copy of the information, especially with zero added value.

We're saying the same, I'm slower, and sometimes I have to correct because I'm not a native English speaker.

[mikedefieslife]

Originally Posted by 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

From this it looks like VWR is much newer, so don't see why it wouldn't be recommended.

Anyhow. My wind data comes in from my N2K network and processed by OPcan.

It seems that the NMEA2000 sentences use negative for port and positive numbers for starboard. Kplex seems oblivious to this, and so when converting to NMEA01803 MWV sentences, just blindly uses the negative figures. The conversion for VWR appears to be better.

[conachair]

Originally Posted by mikedefieslife

From this it looks like VWR is much newer, so don't see why it wouldn't be recommended.

Anyhow. My wind data comes in from my N2K network and processed by OPcan.

It seems that the NMEA2000 sentences use negative for port and positive numbers for starboard. Kplex seems oblivious to this, and so when converting to NMEA01803 MWV sentences, just blindly uses the negative figures. The conversion for VWR appears to be better.

Don't think Klex does any conversion, afaik signalk does that. I've had similar issues with openplotter environment.wind.angleApparent using the sigK - nmea converter plugin, solved by a little bit of node-red to convert from negative to 360deg then send as nmea0183 though sounds like a bug in the app, one day I'll ask on slack. Does OPcan auto convert to nmea?

[mikedefieslife]

Sorry, yes I meant SignalK not Kplex. No Opcan doesn't auto convert from what I can see (again my mistake about the processing). Canbot is used and converts the data in a json format that Signal K can read.

[conachair]

Originally Posted by mikedefieslife

Sorry, yes I meant SignalK not Kplex. No Opcan doesn't auto convert from what I can see (again my mistake about the processing). Canbot is used and converts the data in a json format that Signal K can read.

Were you using the sigK to nmea app? I suspect the authors might be glad to hear of any inconsistencies so will get round to posting this to slack with as much info as poss.

Join the Signal K community on Slack!

[conachair]

Very strange.......

Not doing it now, converts to 0 - 360deg, like the code says it should...
https://github.com/SignalK/signalk-t...tences/MWVR.js

nmea.radsToDeg(angle).toFixed(2),

[Tehani]

Originally Posted by mikedefieslife

From this it looks like VWR is much newer, so don't see why it wouldn't be recommended.

VWR is a sentence not recommended. It is used by some old devices. I have experienced a lot about this.

Originally Posted by mikedefieslife

It seems that the NMEA2000 sentences use negative for port and positive numbers for starboard. Kplex seems oblivious to this, and so when converting to NMEA01803 MWV sentences, just blindly uses the negative figures. The conversion for VWR appears to be better.

It is not so simple, most angles in NMEA2000 are given without sign. Very few: For example Magnetic Variation (declination) and Rudder (commanded and position) are signed.

In any case, you can check this here:

https://github.com/canboat/canboat/b...analyzer/pgn.h

If you look for "wind angle" (PGN 130306), you will see that it sets false after RES_RADIANS. This "false" means that it is without a sign.
Another example: "Rudder position" (PGN 127245), you will see that says "true". This value is signed.
I have checked ALL the standard angles data (and some propietary) of this pgn.h. I can assure you that they are correct. (Garmin, Airmar, Raymarine and almost all of Simrad's match exactly).
I have only detected that Simrad has an error in his "magnetic variation".

[mikedefieslife]

Originally Posted by Tehani

VWR is a sentence not recommended. It is used by some old devices. I have experienced a lot about this.



It is not so simple, most angles in NMEA2000 are given without sign. Very few: For example Magnetic Variation (declination) and Rudder (commanded and position) are signed.

In any case, you can check this here:

https://github.com/canboat/canboat/b...analyzer/pgn.h

If you look for "wind angle" (PGN 130306), you will see that it sets false after RES_RADIANS. This "false" means that it is without a sign.
Another example: "Rudder position" (PGN 127245), you will see that says "true". This value is signed.
I have checked ALL the standard angles data (and some propietary) of this pgn.h. I can assure you that they are correct. (Garmin, Airmar, Raymarine and almost all of Simrad's match exactly).
I have only detected that Simrad has an error in his "magnetic variation".

But in the image I posted above of the of the Signalk diagnostic input, the description for environment.wind.angleApparent specifically says Negative to port.

It is also listed this was in the signalk reference documentation.

/vessels/<RegExp>/environment/wind/angleApparent

Units: rad (Radian)

Description: Apparent wind angle, negative to port

Appendix A: Keys Reference (Vessel) · Signal K Documentation

I'm afraid I'm not really technical enough to know much about it, but I'm had to post any requested outputs.

[Tehani]

Originally Posted by mikedefieslife

But in the image I posted above of the of the Signalk diagnostic input, the description for environment.wind.angleApparent specifically says Negative to port.

It is also listed this was in the signalk reference documentation.

True, SignalK stores the wind angle with a sign. I saw only the name of the group.
The problem is here:
https://github.com/SignalK/signalk-t...tences/MWVR.js

MWVR calls the function nmea.radsToDeg (angle) .toFixed (2) "without correcting the sign, this can be done before conversion to degrees and before configuring the sentence:

*** if (angle <0) angle = angle + 2 * Math.PI
*** return nmea.toSentence ([
******** '$ INMWV',
******** nmea.radsToDeg (angle) .toFixed (2),
******** 'R',
******** speed.toFixed (2),
******** 'M',
******** 'TO'
****** ])

This effect will always be given, you will not be the only person to whom it happens. I think we should inform so that it is corrected.

José Luis

[conachair]

Originally Posted by Tehani

This effect will always be given, you will not be the only person to whom it happens. I think we should inform so that it is corrected.
s

Just asked on slack after creating the prob with a little node red sending random values >

[conachair]

Originally Posted by Tehani

*** if (angle <0) angle = angle + 2 * Math.PI
*** return nmea.toSentence ([

That seems to have fixed it, full marks

Added to the file MWVR.js in
/home/pi/.signalk/node_modules/@signalk/signalk-to-nmea0183/sentences

[Tehani]

Originally Posted by conachair

That seems to have fixed it, full marks

Added to the file MWVR.js in
/home/pi/.signalk/node_modules/@signalk/signalk-to-nmea0183/sentences

Created a Pull Request.

https://github.com/SignalK/signalk-to-nmea0183/pulls

José Luis

[conachair]

Originally Posted by Tehani

Created a Pull Request.

https://github.com/SignalK/signalk-to-nmea0183/pulls

José Luis

And an update has been released, with a couple of new functions to create the positive 0-360. A few minutes to update signalk and restart. Isn't opensource wonderful