OpenMarine

Initial situation : I have an USB GPS receiver connected to openCPC via this openCPN connection :
Network, Input, Signal K, localhost, 3000, 1. And it works OK !
I need to send the position to the VHF NMEA RS232 input. What I did :

• I plugged an RS232 USB COM port in my USB2.0 HUB ;
  
• in SERIAL, I  gave an alias (vhfrs232) to the detected USB port and established a 4800 Baud connection to Signal K ;
  
• In Signal K, I can see the connection,  without any activity (no 'pumping')
  
• In openCPN i created a connection :
  Network, UDP, 0.0.0.0, 10118, opencpnOUT, Transmit GLL.
  
• In SK, I created a connection opencpnOUT
  UDP, 10118, nmea1data (?), Ignored GLL.
  
• finally I edited the device connection :
  vhfrs232, Serial, , 4800, Output Events nmea0183out (?), Ignored GLL
  

I am not sure of what I marked (?), so I need some confirmation. I attach screenshot of my inputs :

[attachment=1387]
[attachment=1389]

Another option...
https://github.com/SignalK/signalk-serve...tting-Data

Hi Didier,

Considering that position input to a VHF is most likely to be useful in an emergency situation, wouldn't you like to have a solution with less complexity involved? A simple standalone GPS with builtin NMEA output would be much more failsafe for this purpose.

Regards

(2021-03-12, 01:38 PM)Knoet Wrote: [ -> ]Hi Didier,

Considering that position input to a VHF is most likely to be useful in an emergency situation, wouldn't you like to have a solution with less complexity involved? A simple standalone GPS with builtin NMEA output would be much more failsafe for this purpose.

Regards

You are 100 % right, all this set of connections looks like a gas refinery (in french : une usine à gaz !). Consequently, I have dramatically simplified the design :
Use of one RS232 NMEA GPS connected to the VHF GPS input;
Redirection in the VHF of position sentences towards the AIS output (a smart option of some recent VHFs) ;
Connection RS232 from the VHF to COM/USB port on the RPi.
RPi will receive both position and AIVDM and send them to Signal K and OCPN;

If the VHF cannot redirect the position to the AIS output then it is possible to connect the GPS TX to both VHF and RPi RXs : in RS2132 one talker can talk to 2 listeners simultaneously !
It is anyway a safe idea to prepare and test this link in case of failure of the VHF, or to save battery on passage making ...

Thanks a lot to have pushed me towards this simplification !

That sounds good, this way you get the shortest data path to the VHF that is the most important listener. One caveat, if the AIS is a transponder that also outputs SOG and COG data (VDO and/or RMC) you may get some strange effects in OpenCPN if those are not exactly the same as the GPS output. If so, some filtering might be needed.

In OpenCPN you are outputting just GLL? And then on the input of SignalK you are ignoring GLL on that input? That doesn't sound right...