NMEA2K over TCP (from can0) to SignalK

[pengu-fr]

I have my nmea2K network available on a can interface on one computer. I have Signal K on an other computer, on the same network.
I want to redirect can0 traffic over TCP to SignalK.

I tried differents TCP NMEA2K sources from SignalK : NavLink2, Yacht Devices RAW TCP, W2K-1 N2K ASCII/Actisense, but couldn't get any of them to work.

To make the can0 available on TCP, I use canboatjs and a convert file with matching filter : pgnToActisenseSerialFormat, pgnToiKonvertSerialFormat, pgnToYdgwRawFormat.

I can see output from the TCP server that seems to be OK :
with pgnToYdgwRawFormat for Yacht Devices RAW TCP :
0df1140b 00 73 d5 ff ff ff 7f 00
08ff460b 27 01 5e f7 d8 27 02 ff
09f10d0a ff 07 ff 7f 7c 02 ff ff
09f80100 6f a7 3b 1a ac bd 82 f3
08ff0011 ff ff ff ff ff 7f ff ff

with pgnToActisenseSerialFormat for W2K-1 N2K ASCII/Actisense
2024-07-14T04:10:01.289Z,2,127250,0,255,8,66,9f,c1,ff,7f,ff,7f,fd
2024-07-14T04:10:01.297Z,2,129025,12,255,8,f4,57,3b,1a,32,94,82,f3
2024-07-14T04:10:01.298Z,2,129025,3,255,8,d2,58,3b,1a,8f,93,82,f3
2024-07-14T04:10:01.299Z,2,129026,12,255,8,30,fc,e6,91,f8,00,ff,ff

I also tried most of other combinasion, without success.

I can see SignalK connect to the TCP server, but it couldn't read any data from it.

my test command : candump can0 | candumpanalyzerjs | node convert.js | nc -kl 6000

How to solve this ?

Thank you

[tkurki]

Have you considered piping raw can over UDP or TCP and do N2K only on the receiving host? https://agill.xyz/tunneling-can seems like a pretty good summary of options.

[pengu-fr]

Yes, but I'm using docker image of signalk. Not easy to modify the node image to add vcan/socketcand.
That's why I wanted to simply configure a TCP (or UDP) connexion in SignalK, pointing to the raw can (ideally) or any converted protocole that SignalK can work with (Actisense, Yacht Devices...)

[sbender9]

I think this would work if you convert to the correct W2K-2 format. That is not N2K ASCII above, what you converting to is different.

Also adding a tcp option for canbus would probably make sense.

[pengu-fr]

It worked ! Thank you for pointing me in the right direction.

My working test command : candump can0 | candumpanalyzerjs | to-pgn --format n2kascii | nc -kl 6000

But I agree, it would be easier to just send the candump via TCP or UDP to SignalK, and let canboat.js do the job there.