gps from rpi to vhf

[whatknot]

Hey I've tried searching but couldn't find anything. I'm running opencpn on raspberry pi with a usb gps puck. I would like to send the gps signal to my vhf radio through nmea but this all confuses me. I've been reading up online but thought I would ask here for guidance. My radio is a standard horizion Intrepid-Gx1260s that came with my boat. Thanks Rob

[Dsanduril]

You’ll need a little more hardware, a USB to RS422/485 serial adapter. Something like this one.

Connect the USB adapter to your Pi. Connect the blue and yellow wires from the radio’s accessory cable to the adapter. In OpenCPN go to the Tools menu and set up a new connection. The USB adapter should show up as a com port. Select that port, set the baud rate to 4800. Select “output on this port”. In the “input filtering” box you will want to set it up to ignore everything (otherwise you’ll create a data loop with the GPS data and overwhelm the system).

That’s the simple version, if you run into stumbling blocks come on back.

[smac999]

I would replace the vhf with one with built in gps. Or buy a nmea 183 gps antenna to connect to it.

Then the pc does not need to be on 24/7. Plus gives you backup gps pos if the pc fails.

[whatknot]

Thanks Dsanduril, I already have the RS422/485 adapter but did not know to set it up as you described. I'm going try that tonight when I get back to my boat. Thank you smac999 but I already have gps multiple or electronics and I'm running this on a raspberry pi rather than a laptop computer. I am doing this more to learn right now.

[Dsanduril]

I said blue and yellow, but it’s actually blue (+) and green (-). If you get no joy at the radio swap the two wires, there’s vast inconsistency in what + and - mean in the industry. Also check your adapter wiring schematic, some adapters require a 4-wire configuration, which means you will have to jumper at the adapter. Usually labeled Rx+, Tx+, Rx-, Tx-, jumper + to + and - to -.

[conachair]

Are you running openplotter on the Pi?
Can't see any reason not to, if so just set up the serial as NMEA in server/connections in the signalk page. Apparently outputs as well received though yet to actually try it.