To answer your question, I do something similar with the SH GX2200. It does work
. I output AIS data (yellow +/white -) at 38400 baud to a wireless multiplexer that combines the boat's Seatalk
data and the GPS data (gray +/brown -) at 4800 baud to the Icom
There are some NMEA output settings, section 15.11 in the manual, that select NMEA sentences are sent. By default, they are all turned off. Section 21.5 shows which sentences can be selected at 4800 or 38400 baud.
Do you have the DB9 pinout data correct
-- pin 2 RD, pin 3 TD and pin 5 ground?
One trick when working with serial data is to use a serial terminal emulation program, such as Putty
so you can easily set the COM ports
, baud rate, N-8-1, etc., and view the output NMEA sentennces. If you see a bunch of $GPXxxxxx, your radio
is properly sending NMEA data to the PC. That would point to OpenCPN and COM port settings, etc.
I also had a weird set of multiple electrical
grounds that introduced noise
into the SSB
. I'm assuming that my radio
network and wireless multiplexer have common negative. I ended up disconnecting the AIS ground wire (white) to the multiplexer/wireless. Strange, but works fine.
Working with serial data sometimes can be a PIA -- I think you are pretty close to sorting this out,