Setting up GPS connection on Open CPN

[matric]

Hello,
I have connected my VHF/AIS radio to Open CON through Actisense USG-1. Open CPN correctly displays AIS targets, but GPS status is set to off and I cannot turn it on. However, GPS information is passed via NMEA sentence as part of the AIS output. Can anyone please help?
Thanks,
Matt

 

[RobbieW]

In Options>Connections open up the NMEA Debug window and have a look at the messages OCPN is seeing. Is there anything other than the AI*** messages ? Are you expecting OCPN to extract your GPS data from the AIS messages ?

What model is the radio ? A search on the spec for that might show if it transmits GPS separate from AIS

 

[matric]

In Options>Connections open up the NMEA Debug window and have a look at the messages OCPN is seeing. Is there anything other than the AI*** messages ? Are you expecting OCPN to extract your GPS data from the AIS messages ?

What model is the radio ? A search on the spec for that might show if it transmits GPS separate from AIS

Hi Robbie,
here's an example of the NMEA sentences received:

Here's an example of the NMEA sentences that arrive:
<GREEN>10:16:50 (Serial:COM3) 6.000,A,5148.3350,N,00101.3872,E,0.0
<GREEN>10:16:52 (Serial:COM3) 8.000,A,5148.3349,N,00101.3872,E,0.0
<GREEN>10:16:53 (Serial:COM3) 1,,,A*6B<0x0D><0x0A>
<GREEN>10:16:53 (Serial:COM3) D0D,0*77<0x0D><0x0A>
<GREEN>10:16:54 (Serial:COM3) 1,,,A*62<0x0D><0x0A>
<GREEN>10:16:56 (Serial:COM3) 1,,,A*60<0x0D><0x0A>
<GREEN>10:16:58 (Serial:COM3) 1,,,A*66<0x0D><0x0A>
<GREEN>10:16:59 (Serial:COM3) @8N,0*61<0x0D><0x0A>
<GREEN>10:17:00 (Serial:COM3) 1,,,A*65<0x0D><0x0A>
<GREEN>10:17:03 (Serial:COM3) 1,,,A*6B<0x0D><0x0A>
<GREEN>10:17:04 (Serial:COM3) 1,,,A*60<0x0D><0x0A>
<GREEN>10:17:05 (Serial:COM3) 8;q,0*55<0x0D><0x0A>
<GREEN>10:17:06 (Serial:COM3) 1,,,A*6D<0x0D><0x0A>
<GREEN>10:17:08 (Serial:COM3) 1,,,A*6B<0x0D><0x0A>
<GREEN>10:17:11 (Serial:COM3) 1,,,A*69<0x0D><0x0A>
<GREEN>10:17:11 (Serial:COM3) @?e,0*03<0x0D><0x0A>
<GREEN>10:17:12 (Serial:COM3) 1,,,A*66<0x0D><0x0A>
<GREEN>10:17:14 (Serial:COM3) 1,,,A*6F<0x0D><0x0A>
<GREEN>10:17:16 (Serial:COM3) 1,,,A*6F<0x0D><0x0A>
<GREEN>10:17:17 (Serial:COM3) <0D,0*09<0x0D><0x0A>
<GREEN>10:17:18 (Serial:COM3) 1,,,A*69<0x0D><0x0A>
<GREEN>10:17:20 (Serial:COM3) 1,,,A*6B<0x0D><0x0A>
<GREEN>10:17:22 (Serial:COM3) 1,,,A*64<0x0D><0x0A>
<GREEN>10:17:23 (Serial:COM3) D0D,0*39<0x0D><0x0A>
<GREEN>10:17:24 (Serial:COM3) 1,,,A*6C<0x0D><0x0A>
<GREEN>10:17:26 (Serial:COM3) 1,,,A*6E<0x0D><0x0A>
<GREEN>10:17:28 (Serial:COM3) 1,,,A*6E<0x0D><0x0A>
<GREEN>10:17:29 (Serial:COM3) 8JC,0*54<0x0D><0x0A>
<GREEN>10:17:30 (Serial:COM3) 1,,,A*6C<0x0D><0x0A>
<GREEN>10:17:32 (Serial:COM3) 1,,,A*62<0x0D><0x0A>
<GREEN>10:17:34 (Serial:COM3) 1,,,A*69<0x0D><0x0A>
<GREEN>10:17:34 (Serial:COM3) @Mm,0*49<0x0D><0x0A>
<GREEN>10:17:36 (Serial:COM3) 1,,,A*6B<0x0D><0x0A>

You see the first two at the top are GPS information. The radio is a RO6800AIS, the manual (attached) does not say whether GPS and AIS are outputted separately. I have setup the baud rate on both the AIS settings on the ration and Open CPN to 38400. I have also tried to open a second connection on the same port with a baud rate of 4800, but that did not help...
Thanks for any help. Matteo

 

[matric]

forgot the manual...

 

[RobbieW]

Any idea what the the message type is for those first two ? They should be GPxxx, I cant see an obvious match for the data format in the reference material I've been looking at. The simplest would be GPGLL but the format looks wrong. The online stuff for that radio says it should forward GPS data, perhaps try it with RS485 only in the AIS output settings

 

[matric]

Hi Robbie,
thanks again for your help, very much appreciated.
I'm unfortunately very dumb when it comes to electronics. The flag 'green' stands for 'message accepted', I do not know where to look for the GPxxx thing you are referring to. Also, I do not have the RS485 option in the AIS output settings, I can only choose between 'AIVDM', 'NMEA2000' and 'AIVDM+NMEA2000'. I currently have 'AIVDM' only...
Matt

 

[RobbieW]

Matt, try the other options perhaps. OpenCPN only reads NMEA 0183 so the NMEA2000 options may break what you have. Otherwise I'm out of ideas, sorry.

 

[edsailing]

Do you have a GPS source for your own position or is the ais information part of the ais target data stream - i.e. does the VHF have its own GPS receiver or is it connected to one?

 

[matric]

Hi,
I have a separate GPS who is talking to the VHF/AIS on 4800 baud rate...

 

[rogerthebodger]

I have a USB GPS mouse connected to my PC running OpenCPN. I also have a RS232 mouse connected to my VHF and my crew saver tag.

You can connect RS232 to more then one receiver sometime depending on the electrical loading of the RS232 receivers.

I would buy USB mouse s set up a separate connection to your PC. I combined all my inputs using NavMonPC and a virtual port to feed all GPS, AIS and instruments to OpenCPN

 

[GHA]

Hi,
I have a separate GPS who is talking to the VHF/AIS on 4800 baud rate...

As mentioned before, something wrong with those messages in your debug window, they aren't formatted as nmea sentences. Which should look like>>
<GREEN>09:47:51 (TCP:192.168.43.93:10110) $GPRMC,094751.00,A,3701.27725,N,00756.65554,W,0.007,,220221,,,A*69<0x0D><0x0A>

You could try connecting only your gps straight to the actisense and see if the gps is Ok, might narrow the problem down.

 

[GHA]

I combined all my inputs using NavMonPC and a virtual port to feed all GPS, AIS and instruments to OpenCPN

Try signalk, really is a million light years ahead...
SignalK/signalk-server-windows

 

[rogerthebodger]

Try signalk, really is a million light years ahead...
SignalK/signalk-server-windows

I'm really only using NavMonPC as a NMEA multiplexer to sent to OpenCPN

I was under the impression SignalK is a message format different to NMEA so would I have to have some conversion to SignalK then back again

 

[GHA]

I was under the impression SignalK is a message format different to NMEA so would I have to have some conversion to SignalK then back again

signalk does pretty much whatever you want, all incoming nmea0183 messages are multiplexed and echoed out again , and you can set preferences if several sources are, say, gps are available. Opencpn can read signalk messages as well without any nmea.

 

[laika]

signalk does pretty much whatever you want, all incoming nmea0183 messages are multiplexed and echoed out again , and you can set preferences if several sources are, say, gps are available. Opencpn can read signalk messages as well without any nmea.

I think the question is why you would want to convert nmea-0183 to signal k to feed to something which accepts nmea-0183? NavmonPC multiplexes and has the ability to set source preferences (as does kplex) without the inefficiency of needlessly converting from one format to another one which contains the same information but uses more bandwidth.

 

[GHA]

I think the question is why you would want to convert nmea-0183 to signal k to feed to something which accepts nmea-0183? NavmonPC multiplexes and has the ability to set source preferences (as does kplex) without the inefficiency of needlessly converting from one format to another one which contains the same information but uses more bandwidth.

You don't have to if you don't want to. But some of the plugins use signalk data from nmea2000 or created by the server which the prehistoric nmea01283 can't do. Opencpn autofinds the signalk server if it exists so even easier to set up for non computer types, much easier to set up the server than the ancient navmon or the very good kplex.
Even if you have a bee in your bonnet about it

 

[matric]

Hi all,
thanks so much for feeding this discussion but can someone please translate it into a non-nerd, dummy user language? I have a GPS connected to a VHF/AIS radio connected to my laptop through Actisense USG-1. The port is set at 38400 baud rate, as the AIS output. OpenCPN gets the AIS targets, but continue to say that the GPS is disconnected.
This is an example of the NMEA sentences as displayed by the NMEA debug tool in OpenCPN:

<GREEN>15:49:22 (Serial:COM3) ,5148.3295,N,00101.3928,E,0.0
<GREEN>15:49:22 (Serial:COM3) 4<0x0D><0x0A>
<GREEN>15:49:24 (Serial:COM3) 6<0x0D><0x0A>
<GREEN>15:49:25 (Serial:COM3) 7<0x0D><0x0A>

Are you guys suggesting to forget about the fact that the vhf/ais knows my position, and connect an additional USB-GPS to provide with GPS data? I have the problem that my laptop has only one USB port, which is used by Actisense. Would you suggest to split it? I am a little bit worried to have all those flying wires and electronic devices connected to each other, I'm sure that the first time I will encoutnmer tough conditions at sea everything will start to fall apart.... Anyway, what are NAVmonPC and signal k for? Can you please provide some very simple explanations and instructions? I am sure these would be of benefit of a number of other un-sophisticated tech sailors as well...
Many thanks again to all who can help.
Matt

 

[GHA]

Hi all,
thanks so much for feeding this discussion but can someone please translate it into a non-nerd, dummy user language? I have a GPS connected to a VHF/AIS radio connected to my laptop through Actisense USG-1. The port is set at 38400 baud rate, as the AIS output. OpenCPN gets the AIS targets, but continue to say that the GPS is disconnected.
This is an example of the NMEA sentences as displayed by the NMEA debug tool in OpenCPN:

<GREEN>15:49:22 (Serial:COM3) ,5148.3295,N,00101.3928,E,0.0
<GREEN>15:49:22 (Serial:COM3) 4<0x0D><0x0A>
<GREEN>15:49:24 (Serial:COM3) 6<0x0D><0x0A>
<GREEN>15:49:25 (Serial:COM3) 7<0x0D><0x0A>

Are you guys suggesting to forget about the fact that the vhf/ais knows my position, and connect an additional USB-GPS to provide with GPS data? I have the problem that my laptop has only one USB port, which is used by Actisense. Would you suggest to split it? I am a little bit worried to have all those flying wires and electronic devices connected to each other, I'm sure that the first time I will encoutnmer tough conditions at sea everything will start to fall apart.... Anyway, what are NAVmonPC and signal k for? Can you please provide some very simple explanations and instructions? I am sure these would be of benefit of a number of other un-sophisticated tech sailors as well...
Many thanks again to all who can help.
Matt

Those aren't nmea sentences, they're garbled and won't get recognized. Try the gps straight into the actisense, at least then you can be sure it works OK and try to find the problem further down the line. Probably better to forget about navmon & signalk for now, they do things with data inside the computer, you need to get the gps data in there first..

 

[TSB240]

My understanding is the op is not using the internal gps of the vhf. I dont understand why but he is currently using an external gps to provide the gps info to the VHF.
The only info the VHF appears to be outputting that open cpn is able to see are AIS sentences.

I would guess that the VHF is not set up for multiplexing the external GPS signal or for outputting a GPS signal.

The manual for the VHF shows that its internal GPS signal can be activated or deactivated in a separate menu to the ais menu.
I suspect that the OP needs to initially try activating this menu and using the internal GPS function in the VHF for primary GPS navigation after disconnecting the external feed.

An alternative would be dump the actisense and get a two channel serial to usb converter. Open cpn can be then be configured to accept both the External GPS or VHF GPS and AIS signals. This would give a degree of redundancy in the event of failure of the VHF GPS and the external GPS could then be used as a back up for navigation without AIS on open CPN.

Steve.
https://cpc.farnell.com/newlink/usb-0039dbl/usb-to-2x9-way-serial-adaptor/dp/CS14391

 

[neilf39]

As has been said your VHF is probably not passing the gps sentences through so only AIS messages are getting to OpenCPN. Is the GPS a coax connected one or a RS232 type? You could try using your VHF internal GPS for its AIS and attach the GPS via RS232 via RS232 to usb convertor if it's that sort. You do have to check what sentences devices pass through. I found my plotter did not pass through a specific sentence I was expecting it to.