OpenCPN SIMRAD/LOWRANCE Radar Overlay PlugIn

[RobbieW]

I've just ordered one of these - Mikrotik hAP AC Lite RB952Ui-5ac2nD. Several reasons; first that it takes input voltage of 10-30; second that the RouterOS developed by Mikrotik seems geared to industrial strength router solutions and, so far as I can tell from reading online info, incorporates support for multicast and bandwidth limiting (useful for metered connections) as well as 3/4G support; finally it was suggested by the ActiveCaptain folk as a reasonable onboard router. Bit of a learning curve to go through then

[rgleason]

Muttnik, Thankyou. I agree, and since it was cutting out perhaps something like
Robbie's Mikrotik hAP AC Lite RB952Ui-5ac2nD would be better. It looks like RouterOS is pretty robust and a learning curve. Page 17 shows level of cost for the software. Software does seem to have IGMP but I would need help configuring.
I think I am going to install the chartplotter and radar and get that working first, then listen...abd follow the learning curve.

[merrimac]

As to the MARPA/RI box latent questions:

1. The real MARPA calculation is done by the chart plotter (MFD).
2. It needs to have a good heading data with each radar scan line (spoke). By the time the data is processed the boat may have rotated, and the spoke transmission time and processing time in the radome may have introduced a delay, so combining heading and a spoke in the MFD introduces errors.
3. The simplest way to solve this issue is to have the radome or RI add "current heading" to the spoke.
4. For that to work the RI box needs the current heading (over NMEA 2000 (RI10) or NMEA 0183 (RI11)) so that it can add it to the ethernet packets itself or send it to the radome so that it can send it.

We know (1) by indirect evidence (relative horsepower in MFD and radome, see below), various comments by Navico employees and by careful observation of the Ethernet network (it can't travel over N2K, as there is no requirement for the MFD to be on the same N2K network as the RI box, and MARPA also works with a RI11.)

We don't definitively know which option Navico has chosen for (4). We do know there is a small microcontroller in the RI box, but that could be a CAN to simpler serial protocol that filters out only the high speed heading data and sends it to a serial port in the Radome's controller, or a more complex one that receives ethernet data, injects the heading, and then sends modified ethernet data out. In my view the first option sounds like the more logical and cheaper option, but who knows.

So what does it mean for us:

• It is safe to route "yellow ethernet" cables with their four wires through normal Ethernet switches, i.e. the "network" side of the RI box.
• It seems prudent to connect all 8 ethernet wires from the radome to the RI, so if you cut it to length make sure you crimp all 8 wires. (Note: it would be really *HARD* to do anything else, but just saying...)

P.S. Interesting tidbit: the MFDs run GNU/Linux on one or more NXP i.MX processors. The N2K and sounder functions each get their own micro controller. The GUI is written using the Qt interface library. The radome though runs Microsoft Windows Embedded CE 4.2 (according to the license sticker on my radome.)

[RobbieW]

Originally Posted by merrimac

...For that to work the RI box needs the current heading (over NMEA 2000 (RI10) or NMEA 0183 (RI11)) so that it can add it to the ethernet packets itself or send it to the radome so that it can send it...

OK, I dont know if I have an RI10 or 11 (not on boat so cant easily check and the local documentation I have doesnt tell what was in the package I bought a couple of years ago). I also got an AT10 with the intention of injecting the heading feed from my Raymarine S3G, (0183) into the Simrad network. I didnt get that to work in the ways I tried, simply by teeing the AT10 off the NMEA feed to OCPN via my laptop then connecting the AT10 to the RJ1x.

Given that I have a chocbloc to tee from with NMEA fast heading on the panel that carries the radar interface bits, what can I do to feed that signal into the radar system ? (I dont especially want to set up an N2K network as I have no other need for it but did buy a Simnet Starter kit that, iirc, included the AT10)

...P.S. Interesting tidbit: the MFDs run GNU/Linux on one or more NXP i.MX processors. The N2K and sounder functions each get their own micro controller. The GUI is written using the Qt interface library. The radome though runs Microsoft Windows Embedded CE 4.2 (according to the license sticker on my radome.)

I'd got as far as realising that the MFD is based on GNU/Linux. Have you found a way to access that system by FTP or with WinSCP ? It'd be very useful to transfer the .gpx files created using to OCPN to the SD card in the MFD without having to manually carry the card between systems. I can access the IP address of the MFD as its on my router network.

Thanks

[merrimac]

Robbie,

There are multiple versions of the AT 10. If your version isn't the one that prioritizes heading (=AT10HD) and your heading source doesn't produce heading at 10Hz or more it is not a valid MARPA heading source for the MFD/radar combo...




Sent from my iPad using Cruisers Sailing Forum

[RobbieW]

Originally Posted by merrimac

Robbie,

There are multiple versions of the AT 10. If your version isn't the one that prioritizes heading (=AT10HD) and your heading source doesn't produce heading at 10Hz or more it is not a valid MARPA heading source for the MFD/radar combo...

As I'm not on the boat I cant visually verify the AT10 variant, however the manual I have on my laptop is for the AT10HD. Also the manual for the Raymarine S1/2/3 series says ..."S2G & S3G computers provide fast heading (HDM) output at 10 Hz 0.1º resolution"

[merrimac]

Robbie,

Not sure what you're after. Do you have a Navico MFD? If not then there is no need for heading-in-radar-data. The plugin can use it but does not require it.

[RobbieW]

Originally Posted by merrimac

Not sure what you're after. Do you have a Navico MFD? If not then there is no need for heading-in-radar-data. The plugin can use it but does not require it.

Kees, in your earlier reply you advocate injecting heading data into the data stream to/from the radar head. You say doing so improves the accuracy of the overlay and MARPA function, I'm trying to follow your advice.

I have a Navico MFD, NSS8, in the cockpit and I use OCPN on a laptop at the chart table. I have HDM sentences coming in to the laptop, what I'd like to do is inject the heading data into the radar stream as advised. I have NMEA 0183 HDM sentences coming from my autopilot; I have an AT10 (possibly HD, possibly not) and I have an RI1x (probably the RI10); I have an ethernet switch, iirc, between the RI1x and the radar head that provides the radar stream to OCPN via a router. I can tee the HDM data at the point where the RI1x and AT10 are installed.

I'd also like to have the NSS8 recognise that heading data is available so that I can use radar overlay on that.

[merrimac]

Originally Posted by RobbieW

I'd also like to have the NSS8 recognise that heading data is available so that I can use radar overlay on that.

Yes, in your case having fast heading on the N2K network is definitely advisable. If you run the N2K network to the NSS you can monitor the network device list and check what type of AT you have, and also check the data that it produces.

[NahanniV]

Originally Posted by RobbieW

.... and I have an RI1x (probably the RI10); I have an ethernet switch, iirc, between the RI1x and the radar head that provides the radar stream to OCPN via a router.
....

Not sure what you mean by head ? MFD ? or RADAR scanner ?

If your switch is between the RADAR scanner and the RI1X you may have a problem:

Based on information posted on this form by Douwe: the cable between the RI1X and the RADAR scanner (head?) caries the heading information on wires that are not used by 10-100 Ethernet; The electrical signalling on these wires is also different from Ethernet.

So, if you put a network device between the RADAR scanner and the RI1X box I think the heading information will likely be blocked.

Cheers,
JM.

[rgleason]

Here are some good alternatives from Sailboat Instruments
Using Nmea 2000 for Radar Overlay
1. Separate the Nmea0183 heading from other Instrument data with two Sparkfun boards.
2. Use an Artisense NGW1 which converts 0182 Heading to the equivalent N2K 127250 PGN (Vessel Heading) and connects to Nmea 2000
3. Then connect N2k to RI10 Simnet connection.

I am trying to understand why I cannot simply do this:
1. Seatalk (Version1) to Gadgetpool.de Seatalk Link bidirectional converter to Nmea 0183.
2. Connect Seatalk Link nmea 0183 to B&G Zeus Touch Nmea 0183 wires in Video cable.
3. Provided there is Heading information in the Seatalk, nmea0183 and Zeus, won't the heading information also be sent out on the Nmea2000 bus?

4. So why is he doing it this way? Perhaps so that he can shut down the Zeus and still be getting heading information to the radar, so that he can be using just a PC with OpenCPN?

-The only problem with this scenario IMHO is the 0183 Instrument Data will not be going out on the wifi or Gopro wifi if the Zeus is shut off.

----
Next year, I think I would prefer to convert the Nmea0183 to Nmea2000 with an Artisense and connect directly to the Nmea2000 bus.

OR another alternative would be to add a Vesper XB-8000 (AIS and Wifi) and connect the Seatalk Instruments Nmea0183 to the Vesper and complete the other connections. Then Instrument data will be available via Vesper wifi to PC and Tablets with OpenCPN, even when the Zeus is shut off. Of course this arrangement will not have the benefit of the B&G app that controls the Zeus.

[rgleason]

4. So why is he doing it this way? Perhaps so that he can shut down the Zeus and still be getting heading information to the radar, so that he can be using just a PC with OpenCPN?

After re-reading, I now think the reason he is doing it this way, is to be able to have a genuine 10mhz heading signal on N2K.

[Hakan]

Notice for translators:
The translation(POT) file for plugin BR24Radar_pi is updated in Crowdin.
Please add your translations.

The reason for this change is a coming minor release of the plugin where a couple of new strings are added.

Thanks
Håkan

[merrimac]

Hi all,

Thanks to Douwe and Håkan we've got a new minor production release, 1.32!

Douwe has polished the UI in several places making it more intuitive what is goind on, and a new simple way to switch on the non-overlay mode. The full list is available at the link below.

Håkan has updated the translations.

My role this time was limited to packaging it up.

This is a great stable release for our summer cruises.

You can get it at opencpn-navico-radar-plugin.github.io for MacOS and MS Windows, and soon via the PPA system for Linux.

[Hakan]

And thanks to Pavel PlugIns for OpenCPN 4.2 | Official OpenCPN Homepage is already updated.