Hello Techstyle,
We have a similar setup on our boat; Raymarine ST60 instruments and ST4000 Autohelm, Raspberry Pi 3B+ with dAISy HAT for AIS. All the Raymarine instruments talk to each other via SeaTalk, a proprietary format from Raymarine. The ST4000 Autohelm has a NMEA 0183 “IN” connection but not a NMEA “out” connection.
NMEA 0183 is a format with one "talker” and up to four “listeners” on one NMEA cable or network. Some people have set up several NMEA networks that all feed into OpenPlotter/OpenCPN/Signal K on a Rasperry Pi. Signal K can multiplex all those signals and output them to other devices over a cable or wifi.
The key is to convert SeaTalk into NMEA 0183. There are 3rd party devices like those of Digital Yacht that can make the conversion.
https://digitalyachtamerica.com/product/st-nmea-iso/ We felt the $200 was a bit steep.
We kept digging and found that Raymarine’s Multi Display repeater instrument has a NMEA “IN” and NMEA “OUT” and does convert SeaTalk into NMEA. These act as a repeater and can be found cheaper than buying a new piece of equipment. I’m still in the debugging stage of the SeaTalk to NMEA conversion. I may have a bad USB converter.
To answer one of your questions, yes AIS is available through the NMEA output. We’ve successfully broadcast the NMEA stream over the Raspberry Pi wifi and can show AIS targets on Navionics on an iPad.
I’ve successfully sent waypoints from our Garmin GPS in NMEA format to the ST4000, so you should be able to create a NMEA stream out from OpenPlotter to the ST4000 AutoHelm.
Let me know if I can help in any other way.
Good Luck!
Geoff
Raymarine ST60 Multi Manual
http://www.c470.jerodisys.com/470Lib/st60mult.pdf
Raymarine ST4000 Manual
https://nyborg-motorbaadklub.dk/onewebme...ndbook.pdf
I'll attach a diagram of our setup with our GPS as the NMEA talker and the ST4000 Autohelm, DSC Radio, and OpenPlotter as a listeners on the NMEA network.
We’ll probably reconfigure our setup to add a NMEA out stream from OpenPlotter to the Multi and make the GPS standalone backup. I believe we’ll need to set up rules on what NMEA sentences Openplotter sends out on the so that Openplotter is not creating an endless loop repeating the information it is receiving.