Little update: all the parts have been delivered. Installed TinyPilot and flashed the Arduino. Then when trying to flash the ESC I had a surprise, no ATMega 8A in an ESC that has been know for that for years. So still waiting for another one to arrive. But apart from that I have started testing my setup on the breadboard 
Will post some pictures later this weekend!
At the moment I have some debugging to do because the IMU errors and the Arduino won't connect. So probably you have to enable hardware UART throug RasPi-config on the Pi-Zero after TinyPilot installation? And I remember that there were some options for initialisation of the IMU as well, I think in the OpenCPN plugin? Will dive into it through SSH soon.
On the bright side: Nokia screen and the buttons worked right out of the box, as does the web-remote page :-)
Will post some pictures later this weekend!
At the moment I have some debugging to do because the IMU errors and the Arduino won't connect. So probably you have to enable hardware UART throug RasPi-config on the Pi-Zero after TinyPilot installation? And I remember that there were some options for initialisation of the IMU as well, I think in the OpenCPN plugin? Will dive into it through SSH soon.
On the bright side: Nokia screen and the buttons worked right out of the box, as does the web-remote page :-)