OpenCPN SIMRAD/LOWRANCE Radar Overlay PlugIn

[Douwe Fokkema]

Hi Hakan and Kees,

Thanks for your rapid reaction. This sounds good, I really would prefer a continious wave (broadband) radar, short range target discrimination is the most important for me. I do react a bit delayed as I was out sailing this weekend, from Makkum out on the Waddenzee. Very close to your hometown Kees!

I understand the Navico is using UDP multicast protocol. This will require some adjustments to my on-board router as normally UDP is restricted to the subnet it is transmitted on. I expect I can sort this out. I doubt if I can find time to start the installation of the radar before my holidays middle of June, so I expect to start work on it some time in August. I will keep you informed.

Groeten, Douwe (http://www.percussion.nl/de_wereldreis/)

[Hakan]

Originally Posted by Douwe Fokkema

.......I understand the Navico is using UDP multicast protocol. This will require some adjustments to my on-board router as normally UDP is restricted to the subnet it is transmitted on. I expect I can sort this out. ....
Groeten, Douwe (http://www.percussion.nl/de_wereldreis/)

Douwe...
Please make a try without any adjustments to the router. My experiances by running through a R is also straight forward without change of settings as long you use wired connections. (wire less is not feasible for a scanner in master mode.)
What I didn't mentioned before is that Win XP-7-8 need changes to the firewall. The easiest is to disable all internal and external firewalls if possible.
Håkan

[RobbieW]

My experience is that running the radar wired thru' a router works for the wired devices but breaks the connection for wireless devices. There may be options to use IGMP/udpxy (ref: http://wiki.openwrt.org/doc/howto/udp_multicast) to make the multicast work wirelessly to required clients and mitigate the effect on other devices - still working through the text and whether its viable on my router/firmware.

[NahanniV]

Originally Posted by RobbieW

My experience is that running the radar wired thru' a router works for the wired devices but breaks the connection for wireless devices. There may be options to use IGMP/udpxy (ref: http://wiki.openwrt.org/doc/howto/udp_multicast) to make the multicast work wirelessly to required clients and mitigate the effect on other devices - still working through the text and whether its viable on my router/firmware.

It seems like UDPXY could work, but it would require a bit of configuration to be added to the plugin.

Perhaps Merrimac or another programmer would be interested in doing this ?

[BMD21]

I’ve been working to get openCpn to display the Lowrance 3g image. I finally got it working in the driveway and this week took it down to San Diego Bay. I’m thrilled, and here are some screen shots.


The first shot shows Journey On headed out of San Diego Bay. The course is stable and you can see the correspondence of the radar with the chart. Notice the radar plot over the bouy markers. That 3G certainly displays detail under about 1 mi range. Those radar signals above the Special Anchorage note are indeed boats moored.



Finally, Glorietta Bay. The picture is certainly more detailed than the JRC I was using. The boats and the shoreline clearly show. Judy is steering the boat, turning to follow the channel and it takes a few seconds for the radar overlay to settle down. Remember the radar is bolted to the boat and turns with it; the chart just stays pointed North.


I’m using an ethernet hub to connect the radar and computer. I did see it work with the radar directly into the computer, but the hub give an easier connection, allowing me to see what line is giving data. Also thank goodness for Wireshark. Solved some problems.
Impressed by both the openCpn display and the 3G radar. Using a chirp gives impressive detail at the short ranges I usually use. And the display is terrific, thanks to Bob G, Dave Cowell and those of you who upgraded the dll.
I’m using the latest dll, version v 0.40529. I have a few questions about the options. In the Radar Overlay options, what does the multicolor and GL3+ do? I didn’t see multicolor and the GL3+ lost the display. Also, under Radar Display, what does Spectrum do?
Anyway, I’m set to go up to Canada next month. Again, thanks to all.

[bdbcat]

BMD21...

I would like to see the pictures, but I get an "Access denied" message on the links.

Thanks
Dave

[BMD21]

Dave, I would be thrilled to show you and get your comments. I think the only way I can post pictures is in an album, because posting them in this blog seem to be beyond my capability.

So I've uploaded the pics to a album entitled "Radar". Since I don't know how to go there from here, here's the link: http://www.cruisersforum.com/forums/album.php?albumid=3697 .

The pics represent the boat on which the radar is mounted, "Journey On", Then come several pictures of areas in San Diego Bay which the text in my above post should describe. Also a pic of the computer in full operation on the galley table.

Any questions, please ask. I'm happier with openCpn than with the Lowrance display. A little problem with their latest HDS 3.0 upgrade.

Give yourself a little pat on the back. And think what you've done to the MFD market.

Boris

[bcn]

You can also post pictures uploading them into your post:
when in "reply/post mode" use the paperclip symbol.
This will open a second window ("manage attachments") which allows you to select the pics you want to post.
Select (one location per line) and then click on "upload" at this secondary window.
The attached pictures will appear at the bottom of your post after "submit reply".

[BMD21]

OK, let's see how that works.

First, the boat in the Broughtens, BC. Then, Glorietta Bay (left, below) showing good detail . Next, beginning of Shelter Isle (right upper,) showing how bouys are pick up and overlaid on chart symbol. And the Coronado Bridge (lower right) showing lag between course and radar overlay.

Well, lets see how that posts.

Seems to have worked well. Thanks, bcn.

Boris

[merrimac]

Originally Posted by NahanniV

It seems like UDPXY could work, but it would require a bit of configuration to be added to the plugin.

Perhaps Merrimac or another programmer would be interested in doing this ?

Not just "a bit of configuration", and not just to the plugin but also to the router, which must run UDPXY.

If you are able to get UDPXY working on your router you might as well add the code to the plugin whilst you're at it.

A major stumbling block is that the control message TO the router are also multicast, albeit at a much lower data rate. Not sure if UDPXY supports this. It seems oriented towards IPTV which is usually multicast in one direction only.

Why do you guys (or gals) run multiple subnets on one boat? Or do you want wireless access?

[BMD21]

Originally Posted by RobbieW

I have found a supplier offering an NSS8/3G scanner combo for little more than the cost of the scanner - thats the route I'm now following.

I just re-read this and I have a word of caution. The vendor I found selling a cheap scanner and display is in SE Asia or near there. The Lowrance display I bought is specifically for North America and loses functionality outside of that area. I also understand they sell a Europe only model. I'm not sure what that impacts, since I'm staying in North America, but I'd check your needs vs what they're selling.

Another comment is that the latest Lowrance update (3.0) provides auto-routes, whatever that means. This doesn't work in North America. No explanation.

Thank goodness the radar will work anywhere. It doesn't know where it is.

Boris

[RobbieW]

Originally Posted by BMD21

I just re-read this and I have a word of caution. The vendor I found selling a cheap scanner and display is in SE Asia or near there. The Lowrance display I bought is specifically for North America and loses functionality outside of that area. I also understand they sell a Europe only model. I'm not sure what that impacts, since I'm staying in North America, but I'd check your needs vs what they're selling.

Another comment is that the latest Lowrance update (3.0) provides auto-routes, whatever that means. This doesn't work in North America. No explanation.

Thank goodness the radar will work anywhere. It doesn't know where it is.

Boris

The deal I bought was a SIMRAD UK deal through the UK dealer network. There do seem to be some territory specific functions in the software, weather (SiriusXM) is one thats US/NA specific. Hadnt yet found anything thats European specific. The main driver for buying was access to all the facilities of the scanner, though now having used it the overlay on OCPN is great as I dont have AIS on the SIMRAD system.

Dave C (+ Hakan & Kees; any others?) - great job!

[RobbieW]

Originally Posted by merrimac

Not just "a bit of configuration", and not just to the plugin but also to the router, which must run UDPXY.

If you are able to get UDPXY working on your router you might as well add the code to the plugin whilst you're at it.

A major stumbling block is that the control message TO the router are also multicast, albeit at a much lower data rate. Not sure if UDPXY supports this. It seems oriented towards IPTV which is usually multicast in one direction only.

Why do you guys (or gals) run multiple subnets on one boat? Or do you want wireless access?

Hi Kees,
Must admit that the comment about getting UDPXY running feels a little OTT to me. I can most likely get UDPXY to run on my router because its mainly an exercise in getting the right bits of code installed and configured - to me thats a world away from coding! I guess I can see the frustration tho'

Muttnik pointed out to me that UDPXY was unlikely to be the answer for the reasons you observe - that its mostly a solution for uni-directional traffic to specific clients rather than the scatter gun of broadcast. Quite why the Navico developers chose that technology for thier implementation with 2 way traffic is beyond my understanding.

I dont know how many I speak for, but for me it would be great to be able to have everything wireless on the boat. I understand there may obstacles in the way of data volume and the strange implementations of OEM developers but its fun ( ) to try and find ways around those and end up with an 'open' system.

[NahanniV]

Originally Posted by merrimac

Not just "a bit of configuration", and not just to the plugin but also to the router, which must run UDPXY.

If you are able to get UDPXY working on your router you might as well add the code to the plugin whilst you're at it.

A major stumbling block is that the control message TO the router are also multicast, albeit at a much lower data rate. Not sure if UDPXY supports this. It seems oriented towards IPTV which is usually multicast in one direction only.

Why do you guys (or gals) run multiple subnets on one boat? Or do you want wireless access?

Thanks for your reply,

I was looking for a way to run OpenCpn with RADAR on a wireless tablet.

Cheers,
JM.

[merrimac]

Originally Posted by RobbieW

Quite why the Navico developers chose that technology for thier implementation with 2 way traffic is beyond my understanding.

I think using multicast is actually the best solution for the problem space (MFD + radar scanners on boats). No IP addresses needed. No DHCP or BOOTP needed. Very low overhead. Works brilliantly with as many MFDs and radar scanners as required, all MFDs will get the data straight from the scanner(s).

Not sure, but I bet that Navico's MFD chart sharing uses multicast as well, it would provide the same benefits.

There is exactly -one- disadvantage to multicast, and that is that "stupid/cheap" routers fall back to 1 Mbit/s when sending out multicast over WLAN, and/or aren't sending through multicast at all. Note that when a higher multicast rate is available and selected that this does define the lowest rate for ALL devices, not just the devices that want to participate in multicasting.

I guess this why Navico uses normal unicast connections for GoFree remote view.

Originally Posted by RobbieW

I dont know how many I speak for, but for me it would be great to be able to have everything wireless on the boat. I understand there may obstacles in the way of data volume and the strange implementations of OEM developers but its fun ( ) to try and find ways around those and end up with an 'open' system.

Sure, that is your prerogative. Just realise that we can't help it when your existing router isn't any good at multicast.

My opinion: do some research on which router (software) works well, and then publish that here. OpenCPN development has taken thousands of manhours, all contributed for free. See this as an opportunity to do something in return.