GPS to VHF

[Techstyle]

Hello All,

Please help a struggling noob! I have been using openplotter on my respi 3 for about a year with excellent results. GPS data is provided by a GPS Puck and this works prefect.


I also have a Navman 7100 VHF which requires a GPS feed for DSC. 

So I bought a bought a usb to serial rs422 to play around and send GPS data to the VHF

I have followed the guide at the link below but still cant get out put to the radio

https://openplotter.readthedocs.io/en/la...-converter

Really could do with step by step walk through if anyone has a similar set up or experienced issue like this before, am sure I have made a mistake in the setup some were.

Also wondering about the baud rate if the gps puck works at 38400 and the radio take 4800 will signal K output the gps at 4800 and is it ok if the baud rates on the devices are different.

sorry about the poor typing using my tiny bluetooth keyboard to type this up on the pi,  will try and post some screen shots of my settings later if that will help.  

Have also swapped the wires around on the rs422 from the radio in case that was an issue. 

Many Thanks for reading

if your VHF radio baud rate is 4800, the RS422 device should be set to 4800 - I found auto didn't work well for me - type in what ever the radio wants

as for wiring - when you say you swapped the wires - did you swap TX for RX?  TX out of the RS422 should connect to the RX on the VHF and vice versa, but you may want to try to reverse the polarity.  watch the lights on the device for trafic and you could type in at the terminal "cat /dev/ttyOP_XXXX" where XXXX is the alias you used for the serial connection

also - you could play with the "Checksum settings" on the radio and try to match them in signal K: 
   

In Signal K you also want to go into "signal k to NMEA0183" settings in server>plugin config and select what to send out - maybe start with 'RMC'