NMEA 2K and OpenCPN - How?

[sapster77]

Hi everybody,

I have just discovered the Open CPN software and its great. I would love to integrate it to my existing system which constists of a Garmin 4008, AIS, wind/log/depth instrument, GPS antenna and a DSC VHF. Its all connected via NMEA 2000. I would use my PC with Open CPN at the nav station for planning and enroute navigation.
Does anyone know how I can connect my laptop (with Open cpn) to my NMEA 2000 network (and thereby the GPS antenna..)??
I have looked at the actisense NGT-1 N2k to USB adapter but I dont know if that is what i need?
Thank you all for your answers

Peter

[idpnd]

Perhaps with an NMEA 2000 > NMEA 0183 converter?

[JesperWe]

A converter is the workaround for now. The Actisense would be great but needs a driver in the OpenCPN code to talk to it's API.

I am currently playing with the CANUSB.com thingie, which is low cost and works well. It would also need a (different) driver of course. I have some code but it is really developed for a different purpose...

[DotDun]

OpenCPN wants NMEA 0183, so you need a gateway. The Actisense NGT-1 is NMEA 2000 only. The Actisense NGW-1 is a NMEA 2000 to NMEA 0183 gateway. I have both these units (as an end-user, not affiliated). I have OpenCPN running behind the NGW-1 with an Airmar G2183 GPS on the N2K network.

I do see one issue with my setup. The ship icon in OpenCPN continually points to a different direction, although the course over ground displays correctly. I haven't done any testing, but I wonder if there is something wrong with the heading translation. A project for the future.

Good Luck!

[sapster77]

Ok! Thanks for all the answers.
So i guess that the NMEA 2K to NMEA 0183 gateway will end up in something like 5 bare wires... can I then connect that to a RS232 and then use a RS232 to USB converter, which I can use in my laptop?
If correct...how is that done...

[sapster77]

Here I go again...
Would i be correct in assuming that this little piece of kit (Maretron usb100) would do the above mentioned...?
It seems to be converting N2K to NMEA 0183 to USB...

Gateway NMEA 2000®/USB - USB100-01 - Electronics - NavStore - Your Pro Marine Source - Detail

[DotDun]

Originally Posted by sapster77

Ok! Thanks for all the answers.
So i guess that the NMEA 2K to NMEA 0183 gateway will end up in something like 5 bare wires... can I then connect that to a RS232 and then use a RS232 to USB converter, which I can use in my laptop?
If correct...how is that done...

In the case of Actisense, the NGW-1 is available as (4) bare wires (ISO) or USB. Obviously, the USB version would plug into your laptop without the need for the USB/Serial adapter. The down side of the USB version is that it limits you from connecting anything else to NMEA 0183. With the ISO version you could connect to your laptop (using a USB/Serial adapter) AND connect to a VHF radio or any other device. NMEA 0183 allows multiple listeners connected to the same talker. The manual that's included shows how to connect things.

[DotDun]

Originally Posted by sapster77

Here I go again...
Would i be correct in assuming that this little piece of kit (Maretron usb100) would do the above mentioned...?
It seems to be converting N2K to NMEA 0183 to USB...

Gateway NMEA 2000®/USB - USB100-01 - Electronics - NavStore - Your Pro Marine Source - Detail

Yes, the Maretron USB100 will work, same caveats as mentioned above wrt USB vs. bare wires.

I choose the Actisense simply on price, it's less $$ than the Maretron.

[sapster77]

Thanks for your help!

Haha, yeah regarding the price....I had just looked at the developers pages and read about the products without looking at the cost first...
It seems the maretron is app. 400$ and the actisense is half the price. Needless to say I will follow in your footsteps and buy the actisense

[manimaul]

I would go with the Maretron for the time being. It supports a wider range of nmea sentences.

Unless after looking here:
http://www.actisense.com/Downloads/D...sue%201.04.pdf
You find that the actisense will convert the data you want.

I can confirm that the Maretron usb100 also works on Linux and OpenCPN conneted to N2K.

[SaltyPaws]

What is the latest on OpenCPN and NMEA 2000? Is the software implementation being worked in opencpn? Any chance that the code for CANUSB.com can be shared? Or is the take, that since you need a device to connect nmea 2000 to opencpn, you may just as well buy a nmea 2000 to 183 converter?

SourceForge.net: Open Skipper - Project Web Hosting - Open Source Software is an open source implementation of the NMEA 2000 protocol

[bcn]

State of the (implemented) art right now is the N2K-->0183 converter.

And as you stated one will need a piece of hardware and software to connect to the N2K bus.

Of course the native use of N2K would be a "nice to have".

This makes only sense though when data beyond those defined in 0183 would be used in OpenCPN.

A lot of those are non-navigational data (engine, battery, tanks, switches ...) so N2K would be more appealing within the scope of OpenCPN if for instance a more general version of the dashboard would be in place. An implementation perhaps that can deal with arbitrary data - data not previously know to the program, pipelining those between the different parts of the program (or plug-ins).

The other point that is needed in the context of N2K is dealing with the existence of several instances of a device - we have something in that direction with the priorities for data sources in the new COM implementation, but in the case of N2K this has to be more general.

So we just need somebody who has the skills, time and motivation to tackle this . CANusb.com is giving already a great kick-start on the part of the N2K protocol I believe.

Hubert

[NahanniV]

Anyone using the AMEC NMEA2000 Adaptor from Milltech Marine:
AMEC NMEA2000 Adaptor

I am considering that one because it translates AIS messages. I don't think the Actisence product converts AIS. Neither seems to support engine monitoring.

I would sure like to see someone create a direct NMEA2000 connection for OpenCPN.

Perhaps a first step would be an open NMEA2000->NMEA183 converter using something like the CANUSB.

It would be great if someday proprietary autopilot messages could be reverse engineered so that OpenCPN could control them like proprietary chart-plotters do.

[bcn]

Actisense does have the option to the stream the AIS data as well.

http://www.actisense.com/products/nm...-1-conversions
http://www.actisense.com/products/nm...is-conversions

[NahanniV]

Originally Posted by bcn

Actisense does have the option to the stream the AIS data as well.

http://www.actisense.com/products/nm...-1-conversions
http://www.actisense.com/products/nm...is-conversions

I see the NGW-1-AIS converts NMEA0183VDM->NMEA2000 but I don't see the NMEA2000->NMEA0183VDM conversion (what I want). Also, there seem to be fewer conversions in the AIS version ?

Am I missing something ?

I don't understand why they have two products instead of one configurable one ? That's why I'm leaning toward the Milltech product. But I would much prefer an open source solution.

Cheers,
John.