Well, the truth is that I have spent a whole day trying to make the invention of seatalk to Signal K work and I must confess that my results have been null.
I tried to follow the instructions of:
https://github.com/SignalK/signalk-serve...k(GPIO).md
And I acquired this optocoupler circuit:
https://es.aliexpress.com/item/400114570...63c0AT6Q3a
And also this other version that I like better and based on the same optocoupler:
https://es.aliexpress.com/item/327199577...63c0AT6Q3a
Null results in both methods. At hardware level I would say that they worked fine. As soon as I connected the seatalk signal, the LEDs would flash and the output of the optocoupler would repeat the signals at a lower voltage -above 13 Volts in seatalk and above 3 Volts at the output of the optocouplers.
I never saw any data entered into signal k or using the test script. I tried other GPIO pins instead of the 4 and nothing. Inversion connection, no inversion as well. I also tried the simplest method using the transistor, in my case a BC547 which is also NPN and runs at a very similar voltage also with no results.
I still have to test the assembly of:
https://github.com/Thomas-GeDaD/Seatalk1-Raspi-reader
But I have the impression that there is something about the software that escapes me and I do not know what it is. I have tested it on Openplotter32bit and Openplotter64 without any difference in the results. And I know that my seatalk network works well because I have a seayak to nmea0183 converter and it works fine.
I am totally baffled and tired. I suppose that my lack of results is due to chronograf that, to tell the truth, I did not even remember that it was installed and that by the way I do not know how to change port since the configuration in openplotter-dashboards takes me to localhost:8888 but there is nothing in such place. Although a port scan tells me that:
8888/tcp open sun-answerbook
...but I don't know if is talking about cronograf or gpiod using that port right now.