read and use signalK data

[wefleenor]

Is it possible to have Openplotter receive signalK data from another server and use those data in Openplotter? Thanks.

[B25Matt]

Openplotter is a Raspberry Pi Linux distribution that contains a number of pre packaged marine applications. Two of the primary apps being OpenCPN (a chart plotter) and SignalK (a marine data aggrigator).

I think your question is, can one SignalK instance send data to another SignalK instance and the answere is yes. These can be running on the same computer or on a separate computer.

SignalK is very flexible. Once all the data flowing to a master SignalK source, OpenCPN can be pointed to that data source for its required data.

I hope this helps you understand some of the nuances of the various terminology.

[verkerkbr]

You can use the data of SignalK simply on other systems. Point in the receiving system:

network signalK (then the ipadres of the server can be wired or wireless) port 3000

The signalK dashboard is: (Ip adress server):3000

It is HTML en can be used on every system.

Then can also be done with the instruments application MXTommy/Kip:

(Ipadres server):3000/@mxtommy/kip/#/page/0

But you have to install MXTommy/kip first from the webapps and arrange all your instruments.



Bram

[wefleenor]

My apologies for failing to properly define my question. I currently run a Pi4 with openplotter that takes in gps and depth from nmea2000 and heading from nmea0183. I also have radar overlay on it. I wish to run a second Pi4 with openplotter just to have a full screen and view on a different scale the plotter. How can I retrieve the gps from the first Pi4 so the plotters are synced? Thanks.

FWIW - I have a 3rd Pi4 which I sue to obtain the signalK data and plot values of interest.

[Dsanduril]

The options are myriad, some depend on how much you want to get into the details. And some depend on how you have the signals configured on the primary (do they go into Signal K and then into O, or are there connections to the signals directly in the Connections tab of O?).

To me, by far the simplest, if OpenCPN is always running on the primary Pi, would be to go into OpenCPN on that Pi, configure a new network connection, "output on this connection", filter the output to only the sentences you actually need on the remote installation.

On the remote installation in OpenCPN create a new network connection and point it at the primary system. Voilà, whatever data you told OpenCPN to put on the network on the primary is available to the remote.

You can also easily do the same thing using Signal K, and by default the Signal K server is already running as a service on the primary, in that case you would create a new network connection on the secondary and point it at the Signal K server on the primary.

There are probably a half-a-dozen other ways to skin this cat, the point being that once the data is on the first Pi it can be put on a network connection and from there any device on the same network can receive the data.

[Lake-Effect]

Originally Posted by wefleenor

FWIW - I have a 3rd Pi4 which I sue to obtain the signalK data and plot values of interest.

Wow, I've heard Americans are litigious, but I didn't think it extended to single board computers.

(but seriously, very interesting thread )

[SCarns]

I'm not convinced there is a real good reason to run multiple instances of SignalK on a boat. It seems to just over-complicate things. The whole point of SK is to get ALL the data from different sources and protocols in one cohesive system, which then disseminates that data. In my set up, I have two Pis (about to add a third), but only one is running SignalK and everything else connects to that. Just my way of doing things...

[rgleason]

Don't forget our SignalK pages here
and if you have additional information please edit. (if you are a regular user, just PM me)

[wefleenor]

Thanks Dsanduril, I think I can work out the details from your explanation.

SCarns, would you care to share how you connect the others to the server? Thanks.

[verkerkbr]

Originally Posted by rgleason

Don't forget our SignalK pages here
and if you have additional information please edit. (if you are a regular user, just PM me)

Hi R. Gleason,

what is missing is how to install SignalK server on exsisting Linux system:

At first you need to install NPM (nodejs): sudo install npm.

Then the installation of SignalK:

sudo npm install -g --unsafe-perm signalk-server

Then must set the SignalK server to start:

sudo signalk-server-setup

Most of the items are: no

Then the signalK server starts at the starting of the system.

SignalK is HTML en can the dashboard be used in every browser: localhost: 3000

Or from a remote system: ipadres signalk server: Ip:3000

in OpenCPN you can use the signalk direct with: netwerk localhost signalk and poort 3000

From a remote server change localhost to ipadres of the server computer.

Windows install is also posible but not with the above procedure.


Bram

[SCarns]

Originally Posted by wefleenor

SCarns, would you care to share how you connect the others to the server? Thanks.

I connect mine through wired ethernet and a router, but wifi would work well and the Pi can be set up as a wireless access point, so you can connect extra Pis to that one pi via wifi.

[wefleenor]

Thanks, SCarns.

[Bronno Mulder]

I installed SignalK on a Raspberry. This Raspberry is directly connected with Tinypilot as the server. On the Raspberry I connected a GPS receiver with an USB connection. That is all working well and I see in SignalK the data coming in, from the Tinypilot (compass) and from the GPS receiver (satellite).

On a tablet I installed OpenCPN with a Netwerk connection to SignalK/ Network/ IPadress of the Raspberry/Network port 3000. If I use the NMEA debugging of OpenCPN, I don't see any data coming in or going out. Also no GPS or Compass connection.

My question: A SignalK connection from OpenCPN on the tablet, can I normally see data that is coming in with NMEA0183 (what I expect with debugging)? Or is there a special reason for no connection between SignalK and OpenCPN?

Thanks

[Hakan]

Bronno..
Protocol:
NMEA0183 and Signal K data are two different data formats. SignalK data can't be seen in "NMEA Debug window"

If you want NMEA0183 from SignalK(SK) you have to use protocol TCP and port 10110.
If you want SignalK data from SK you have to use protocol Signal K and port 3000. (Please disable "Automatic server discovery" once used.)

The connection between OCPN and SK works fine if the tablet and Raspberry are both connected to the same IP network segment. (Like e.g. 192.168.1.xxx)

[rgleason]

Some of these reports have been added to the Opencpn - SignalK manual.
Please feel free to add and edit this manual. I can't be relied on to do this all the time.
If you need access PM me!