Server Hardware for openplotter?

[flybob]

I got my autopilot connected to N0183, Led is lit on the input port (middle right).
In Serial app I've defined SC4 as ttyOP_outpilot
SignalK also shows it, baud rate is correct.
No deltas at all from the input in SignalK

I don't get any input at all, even when doing a cat /dev/ttyOP_outpilot it's all empty.

Any ideas?

Also, do I need to connect the signal gnd? The autopilot doesn't feature a signal gnd connector