Plugin: DashBoard

[conachair]

Originally Posted by Schnapsy

Thank you very much !

With signalK installed, I will now try to draw new screens and adapt my nmea0183 sentences ...

One last question, if I may ...

Is it possible to feed signalK directly via a txt file (like VDR files) in order to make simulations ?

N.B.: it works too with FireFox...

You got up and running then! Well done

Many ways to save to a file, easiest probably just enable the logging option in the server/connections page. Can't remember where it logs to but it will say somewhere in there. If you want to just save one message type, like AIS then node-red can do that for you.

[teppokurki]

Originally Posted by Schnapsy

Thank you very much !
Is it possible to feed signalK directly via a txt file (like VDR files) in order to make simulations ?

When you started the server with the --sample-nmea0183-data option it in fact tells the server to start up with a configuration file that instructs it to start playing back a log file that contains nmea0183 data.

So yes, you can feed it simulated or captured data from a log file. Start the server without the --sample-nmea0183-data option and configure a new data connection at Server => Connections => [Add] and then
- Input Type: File Stream
- ID: nmea0183fromfile
- Data Type: NMEA0183
- File Name: /path/to/your/logfile/in/ubuntu
[Apply] and restart the server.

[teppokurki]

Originally Posted by rgleason

OK, it is another translation/language that makes Nmea 2000 accessible and opensource so that better tools can be used to analyze and display the data?

(1) Signal K is a data model: a way to represent marine data

Signal K defines paths that are used to tell what a datum is: navigation.speedOverGround or environment/outside/temperature.

So instead of encoding speedOverGround in a cryptic message like $GNRMC,001031.00,A,4404.13993,N,12118.86023,W,0.14 6,,100117,,,A*7B (NMEA0183) or 8,00,4e,01,ff,ff,00,ff,ff (NMEA2000 pgn 128259 data as hex) we send a message like

{"path":"navigation.speedOverGround", "value": 3.34}

It also defines standard units for each path in a schema.

(2) Signal K defines some interfaces for accessing the data

Signal K specification defines how an application can
- connect to a Signal K server
- retrieve some or all of the latest values
- subscribe to receive some or all of the updates that the server sees
- send new sensor data to the server
in a modern, internet, browser and smartphone friendly way.

In OpenCPN each plugin must parse the NMEA0183 data separately - there is no central data model. Contrast that to a SK server, where all incoming data, be it NMEA2000 or NMEA0183 or some other non-NMEA sensor data, is converted first to Signal K and then made available to all the different parts of the system.

In this thread there has been talk about different plugins doing calculations differently. In a SK system we can also derive data, for example calculate true wind, and this derived data will be available like the original sensor data for all applications. Another example would be applying calibration to incoming data: I have a piece of code that adjusts magnetic heading to parameters specific to my boat. This is also done once and the adjusted data is what is available for all displays/gauges.

All data in a uniform data model makes dealing with it much easier. A few days ago somebody asked about sending Signal K data to a cloud IoT database. This is what the code to do that looks like

const ws = new WebSocket('ws://localhost:3000/signalk/v1/stream')
ws.on('message', function incoming(data) {
  const msg = JSON.parse(data)
  msg.updates && msg.updates.forEach(update => {
    update.values && update.values.forEach(pathValue => {
    const msgOut = {}
    msgOut[pathValue.path] = pathValue.value
    const theMsg = JSON.stringify(msgOut)
    client.publish('v1/devices/me/telemetry', theMsg)
    })
  })
})

The complete example: https://gist.github.com/tkurki/b1658...e611f03de84698
From an application developer's perspective this is a lot easier than dealing with NMEA data.

The ability to store the data in a database easily and draw graphs based on it that conachair touts comes from the uniformness: you don't need to write separate logic for each and every datum, just a single mechanism for writing SK data to the db.

In fact one motivation for myself when starting out with Signal K was the need to have one way to deal with various data: I had written some code for myself based on NMEA0183. Next season I switched my wind gear to NMEA2000. Instead of rewriting the code in an NMEA2000 specific way I converted it to use a data format that does not really care where the data is coming from.

At the same time you get the benefit of easily debugging stuff: it is way easier to figure out what's happening if you see a SK path compared to unparsed NMEA data.

With Node Signal K Server you get some other niceties, like
- appstore where you can install & update extensions (for example derived data formulae or plugins for writing SK data into databases locally or in the cloud) and webapps (customizable dashboards and gauges that work in browser on computers and smartphones)
- secure and authenticated access to your data
- playback & snapshot support: the ability to stream or retrieve historical data
- logging: you can log all your data
but these are not part of the Signal K specification, data model and protocol, merely features of this particular software.

[Canne]

Hi Schnapsy, nice to hear that you managed to install the Signal K node server. It is stable and amazingly fast swiss-knife-like service between you and your boat's instruments, no matter how they are connected. For its output features you have only scratched the surface! Under the hood you will find many useful incorporated functions and plug-ins. Like this:

Originally Posted by Schnapsy

Is it possible to feed signalK directly via a txt file (like VDR files) in order to make simulations ?

Yes, please see the attached excerpt of my test use case tc107 for Signal K functions in DashT - jump to step 6 and you will find what you need.
2019-11-07_test_case_tc107_pgs7-8.pdf
For your convenience, I have added the the test file mentioned in the document here as well (with the usual extra file extension you need to remove first):
tc107_HDM_with_extra_file_extension.zip.pdf
Best regards,
Petri

[rgleason]

Thanks.

Is the signalK server, software or hardware?
What is necessary in terms of hardware and software to move

nmea0183 --> signalK
nmea2000 --> signalk
signalK ---> nmea0183
signalK ---> nmea2000


Can this be done with the windows version?

[Schnapsy]

Thank you all, Petri / Canne, Conachair, Teppokurki, for your very clear and detailed explanations.
I now have to dive into this new world of signalK and for what I have already read, I have a lot to learn.
But this is interesting and will be useful.

@Rick,

I do not know if there is a SignalK topic in the opencpn Wiki.
If this is the case, it would be wise to put Conachair's explanations on the installation of SignalK on Win10.
It has been very useful to me and could also be used by others.

If it helps, I can participate in the writing of this topic but not immediately because I prefer to first check - step by step - all the explanations that I could detail in this section.
Because it is not enough to install SignalK, I must also know how to use it properly.

[rgleason]

Ok, since we have one volunteer (Schnapsy) to edit and maintain it, there is a new SignalK page under Supplementary Software that is blank and ready to be filled with wisdom and good links.


If anyone else wants to be an editor of this page, PM me.

[rgleason]

Dashboard-Tactics now has its own dedicated thread. Please use it for DashT questions and discussion.
Dashboard-Tactics (Dash T) - Cruisers & Sailing Forums

[attl]

The GPS format in the dashboard is always Grad,Dezimalminutes and is not possible to change to Grad,Minutes,Seconds.. Any idea how i can chnge the information ??

[Hakan]

attl... (Welcome to the Forum)

In Dashboard plugin the position format is hard coded and cannot be changed by the user as in OCPN core program. Other units can though be changed in Dashboard's Preferences->Appearance. (Right click in the Dashboard window)
/Håkan

[crusin_canuk]

Hello,


I'm running into a bit of difficulty getting the magnetic heading from my fluxgate compass to display in the Dashboard using the "Mag HDG" instrument. The fluxgate compass is transmitting a HDM sentence, which seems to be good, as I can see it on my radar display. I noted in Eric Raymond's explanation of NMEA 0183 sentences that both OpenCPN and Dashboard should accept the HDM sentence. So, I'm wondering if I have to change a setting in OpenCPN/Dashboard or has something changed in Dashboard/OpenCPN such that I need to use a different NMEA sentence?


Thanks.


Paul

[Alicja]

Hello,
what can I do, to make Dashboard show the "Trip Log" and " Sum Log" values? All other parameters are being read from NMEA 2000 without any problem, gps position is know, the track recording is on, but the log shows nothing.


best wishes
Alicja

[Hakan]

Alicja..
Dashboard would be prepared to use PGN 128275 for trip- and sum- log.
Unfortunate it's not very well tested in real.
Can you in some way confirm the PGN 128275 is present into OCPN in your system?

BTW: Welcome to this forum!

Thanks
Håkan

[Alicja]

Originally Posted by Hakan

Alicja..
Dashboard would be prepared to use PGN 128275 for trip- and sum- log.
Unfortunate it's not very well tested in real.
Can you in some way confirm the PGN 128275 is present into OCPN in your system?

BTW: Welcome to this forum!

Thanks
Håkan

I may test it. I have another GPS sum log in another device, so I can use both and compare the results. I'm sailing about 5-6 thousand miles a year, so it would be enough to test, I hope.


Sure I can confirm, if you tell me how to check it.

[Hakan]

Sure I can confirm, if you tell me how to check it.

That depends on your system. I'm sorry but OCPN can't trace received PGNs. You have to check your system if the devises are using PGN 128275

Here's the result of our testing during development with a captured N2k data file including PGN 128275. I retested today: