Pypilot with ST4000 autohelm

[Peter—]

Thanks Ironman - That is exactly what I want to do - but why do I need an adapter when I have Txd and rxd pins? 

There must be a way to use that instead + that would enable me to use an esp32 which I would really prefer to avoid pulling wire. I just pick up the nmea on udp from the pi and transfer it over txd to the nmea- port would be my guess. Am I right? Or is there a voltage problem or something? Would do I ground it?

Br, Peter