How Do I Overlay DSC Waypoints / Track Buddy

[tebsin]

Hi all
Maybe its wishful thinking, but is there any way of displaying DSC data from a DSC enabled VHF/HF as an overlay on a chart, this feature would be very handy when travelling in a group, ie track buddy feature.
Thanks in Advance

[gdavids]

I am also very interested in being able to have position polling positions from DSC displayed on the chart. Is there any way this is possible with OpenCPN?

[PjotrC]

In a couple of weeks I shall be sailing, so the development season will end.

I have one feature left in the backlog: plotting NMEA 0183 CDDSC and CDDSE messages and GpsGate Buddies (FS#331). I have this working in the 2.3.1 1228 release, but not yet in the current 2.4 0324. The question is whether to make the effort of integrating this code now.

I implemented this early in January, seemingly along with multiple specific requests in this Forum, but no feedback so far... so I am just wondering, whether to continue this work.

Pros:

- most chartplotters and PC-based nav software include CDDSC/CDDSE plotting today
- having the DSC Distress position immediately plotted on screen is certainly a good thing
- polling the buddies around may be lots of fun and can reduce the load on voice VHF channels

Cons:

- the AIS code seems to be in a process of being prepared for moving to a plugin, so adding complexity now would not be welcome
- it is not too easy to live test - it takes more skills and equipment than just the PC at home
- most people expect the DSC Transponder Initialize function here, so they will feel disappointed without it, whatever other benefits are present

The DSC Transponder Initialize relates to "clicking on an AIS target to get connected over VHF to it". But this is very rarely supported by the communications equipment. Also, by the nature of GMDSS operation it can not be fully automatic, it can just save punching in the MMSI, but not the channel selection and not making the actual call. For collision avoidance I would always prefer to make a voice call than an Individual DSC call, whatever the interface. So I think it is not worth implementing DSC TI now.

I did the CDDSC/CDDSE and GpsGate testing with all the data I could find around, but I am not prepared to write a simulator or set up a GpsGate server for testing. I shall have access to a DSC-output capable VHF in May, but likely I will be busy then with other things.

Any keen builders enabled to test?

Piotr

PS. The patch is already in flyspray (FS#331) anyway...

[gdavids]

I am not a developer or builder, but if you have a version that just needs testing, I could help with that. Since I would love to get this feature working, it is well worth my time. I live on my boat with a DSC radio and have friends with DSC radios I could ping.

I currently have build 2.4.324. Should it be working in this? Is the data supposed to come in in on the same port used for GPS? If so, what is the easiest way to combine the two NMEA feeds (GPS and DSC) into the one port? I am using the Standard Horizon GX2100 for AIS and DSC.

Cheers,
Greg

[PjotrC]

Originally Posted by gdavids

I currently have build 2.4.324. Should it be working in this? Is the data supposed to come in in on the same port used for GPS? If so, what is the easiest way to combine the two NMEA feeds (GPS and DSC) into the one port? I am using the Standard Horizon GX2100 for AIS and DSC.

Greg...

I will produce a working 2.4.324 then.

The DSC feed will be expected in the AIS stream, so it should naturally interface to your GX2100.

I am not sure if the executable I produce will run for you simply by replacing the opencpn.exe. The process for building a distributable package breaks for me, so I can only publish a source patch or a wishful executable. Maybe someone can build a better .exe then...

In the meantime you could perhaps:

- try to download the .exe I posted in the Routeplan Time & Tide thread today, if Windows is your platform
- record & post here or PM me some data for testing

Thanks in advance,

P.

[gdavids]

The SH GX2100 radio outputs the DSC data separately from the AIS data. They are also at different baud rates. AIS is at 38400 and DSC is at 4800.

Greg

[PjotrC]

Originally Posted by gdavids

The SH GX2100 radio outputs the DSC data separately from the AIS data.

It is good to test ...

Until you will find a suitable multiplexer (software or hardware) you can connect DSC NMEA output from VHF to AIS input of OCPN. Today OCPN can feed the GPS from AIS stream, but not the other way around. Something to think of when moving AIS to plugin...

The source patch is attached. Please let me know if there is any use for posting the Windows executable.

In any case the recorded data stream would be useful.

[Plexi47]

Hi all,
sorry for my nooby question.
How can I install the patch in the OpenCPN program ?
Using W7.
Thanks
Mauro

[nohal]

Mauro,
you have to compile from source, not worth the effort if Compiling - Windows | Official OpenCPN Homepage sounds like Mongolian to you... If not and you pass through it:

git help apply

Otherwise you will have to wait until someone builds the modified binary.

Pavel

[Plexi47]

Originally Posted by nohal

Mauro,
you have to compile from source, not worth the effort if Compiling - Windows | Official OpenCPN Homepage sounds like Mongolian to you... If not and you pass through it:

git help apply

Otherwise you will have to wait until someone builds the modified binary.

Pavel

Many Thanks Pavel,
Understood, I've to wait.
Hope it will be included in a future release.
Mauro

[PjotrC]

Just in case...

[Plexi47]

Unbelievable !!!
With very limited experience in programming (Visual.net for dummies),
after some struggling, following Compiling - Windows | Official OpenCPN Homepage
instructions.
I've been able to compile a version for Visual C++.
Then I had to apply the patch.
Just because I'm not able to see if it works.
I'm at home , only in June on boat, could you pls tell me if the procedure I followed
is correct:
- rename the patch.doc published by Pavel as DSC.patch
-create a subfolder : patches
cd to that subfolder
git apply DSC.patch
git states he has eliminated some blank lines
recompiled the solution
Do you think it worked ?
Thanks
Mauro

[nohal]

Congratulations!
It did work. You can actually omit the step with creating the subfolder for the patch - it can be anywhere, what's important in this case is that you run git apply inside the repository.

Pavel

[Plexi47]

I've to congratulate with You All for the clear instructions.
If I've (almost) succeeded is because of that!
The only problem I 'm now facing is the impossibility to create a package.
The log_file states:
Error: Can't open "C:/..../opencpn/buildwin/NSIS_Unicode/UI/opencpn_ui.exe"!

In fact that file is not there

Any solution ?
Thanks again
Mauro

[nohal]

Mauro...
It is there, at least in the repository - SourceForge - opencpn/opencpn/tree - buildwin/NSIS_Unicode/UI/
Make sure that you created the build folder under the path where you cloned the source and are running the build there.
Anyway if you got that far, you already have the opencpn.exe built, so just find it in the Release subfolder of the folder where you run the build and replace the one that came with your opencpn installation and you should be done.
One more important note - you have to build the Release configuration, with the debug build things will not work if you replace the installed executable...

Hope it gets you going

Pavel