OpenCPN and Electronics Configuration

[rgleason]

I started to post this in the Simrad Radar thread. I am glad I did not.

I am trying to plan an upgrade to use Broadband Radar, AIS and Nmea over IP Wifi. The current equipment is
1997 ST4000 Wheel Autopilot seatalk
2005 ST60 Wind and Tridata seatalk
1997 Autohelm Fluxgate Heading Sensor M92580 which outputs Nmea
2013 Globalsat BR-355 GPS hardwired+5vdc to VHF & Autopilot
I am retiring the 1997 RL9 Radar next year.

The Heading Sensor outputs Nmea 0183. Is this adequate?
"Magnetic Sensor NMEA 0183 HDM, HDT, VHW or HSC, data sentences. "
"Designed to output NMEA 0183 HDV sentence for the radar, can supply data for up to 2 external Nmea 0183 inputs."

As far as I can determine, Heading Data is needed for
- Radar - Direct wire from Fluxgate to Radar - OK
- ST4000 Autopilot (1) Nmea In on the Autopilot wired to GPS OK
Can hardwire GPS Nmea signal or Fluxgate Heading, but not both.
I am removing the old RL9 Radar which also had a Nmea In for the Heading. I do not know if that got onto the Seatalk Bus. Does Wind or Autopilot need heading? - I think so.

Here is what I think needs to be done:
-------------------------------------------------
BR-355 GPS Mouse hardwired to VHF Nmea In
BR-355 GPS Mouse hardwired to ST4000 Wheel Nmea In
Flugate Heading hardwired to Radar Nmea In (can do one more Nmea)

New Seatalk-Nmea Multiplex Wifi Device
Seatalk ---> Nmea In Converts Seatalk + GPS data
Seatalk <--- Nmea Out Allows WPTS, XTE to be sent to Autopilot
AIS Nmea ----> Nmea In AIS on Opencpn, & AIS GPS as Priority2
Heading Nmea --> Nmea In (Do I need this for Autopilot & Wind?)

+ Wifi Ship's OpenCPN and Android Tablets. (no wires)
------
Option: Add a USB to plug in the GPS Mouse, then the Heading sensor could use that Nmea In on the ST4000 Wheel.
However the GPS would still need to be wired to VHF/DSC.

Option: Also you could add one or two ethernet ports in hopes that someone will figure out how to transmit radar over wifi (Furuno does this) so we would have no wires other than power to our computers.

Next year, add Broadband Radar with USB 3.0 to Gbit Ethernet ($20)
connected directly to the radar ethernet with power and heading wires.

I am considering not connecting VHF/DSC to Opencpn because it gets too complex, so this information will not be available on computers unless the AIS takes care of it.
VHF/DSC Nmea ---> Nmea In
VHF/DSC Nmea ---> Nmea Out
What is lost by doing this?

Unknowns:
- Does ST60 Wind require heading data?
- Does AIS require heading data?
- Does the AIS send GPS data interleaved at 38000 baud?
- Does the AIS provide VHF/DSC Nmea In and Out connections?

Sorry I was going to limit this to two questions, did not succeed. Any thoughts would be appreciated.

[rgleason]

I probably should have posted this in the Electronics Forum.

After looking into the Data needed by the ST50 Autopilot , I believe that the Fluxgate Heading Data is most important, and I think that that would also be true for the ST60 Wind. Therefore the single Autopilot Nmea In connection will be Fluxgate Heading data.

As a result the Seatalk Instruments will not have GPS data initially until and unless the Mux Nema data is sent back to Seatalk.

[rgleason]

RhythmDoctor posts provided some alternative ideas again.

http://www.cruisersforum.com/forums/...ml#post1727663

My AIS (receive only) comes from my SH GX2150 radio. I covert it (and Garmin 18x LVC GPS) to Bluetooth with two industrial serial-Bluetooth adapters.

If it communicates via NMEA 0183, then the data stream is so slow that current Bluetooth or WiFi technology would work with no problem.

Check this thread for my power readings, which are amazingly low for the tablet http://www.cruisersforum.com/forums/...ml#post1688289

ZyXEL travel router sips only 1.3-1.5 watts of power
Sailtimer Wind with Bluetooth4
vYacht wifi

RS232 Bluetooth Serial (master-slave) Mini USB MB $10
RS232 Bluetooth Serial Adapter Communication Master Slave 2 Modes Mini USB MG | eBay

http://www.cruisersforum.com/forums/...tml#post624394

Schematic Design of Serial Bluetooth & tracking down Autopilot send BT problem
http://www.cruisersforum.com/forums/...tml#post624647

So RhythmDoctor why are you now installing vYacht?

[Tupaia]

Originally Posted by rgleason

Unknowns:
- Does ST60 Wind require heading data?
- Does AIS require heading data?
- Does the AIS send GPS data interleaved at 38000 baud?
- Does the AIS provide VHF/DSC Nmea In and Out connections?

Sorry I was going to limit this to two questions, did not succeed. Any thoughts would be appreciated.

I can answer a few of the unknowns:

The ST60 Wind does not need Heading and will run standalone. Ground wind, that does need heading I believe is generated by ST60 (Multi or Graphic).

AIS does not need Heading. Everything is calculated from GPS, Position, COG and SOG.

Not sure why you would hard wire Heading into the 3/4G radar. The RC42 heading sensor for example simply adds Heading to the SIMNET or NMEA2000 streams. The radar itself does not need Heading, it just outputs data and you only need Heading to display it at the correct orientation on a plotter.

Hope this is of some help.

[rgleason]

Thankyou this helps. My old radar required nmea heading, I understand now that ocpen uses it for the overlay of radar.

[Dockhead]

Originally Posted by Tupaia

I can answer a few of the unknowns:

The ST60 Wind does not need Heading and will run standalone. Ground wind, that does need heading I believe is generated by ST60 (Multi or Graphic).

AIS does not need Heading. Everything is calculated from GPS, Position, COG and SOG.

Not sure why you would hard wire Heading into the 3/4G radar. The RC42 heading sensor for example simply adds Heading to the SIMNET or NMEA2000 streams. The radar itself does not need Heading, it just outputs data and you only need Heading to display it at the correct orientation on a plotter.

Hope this is of some help.

The radar does need heading, and several functions are very sensitive to quality of heading data. I believe the Simrad needs it in N2K. You will want to acquire a quality stabilized N2K heading sensor (Airmar H2183 is the best reasonably priced one) and create a mini N2K network. The H2183 will also output 0183 if that's what your pilot needs.

Sent from my D6633 using Cruisers Sailing Forum mobile app

[rgleason]

Thanks Dockhead. There was another sensor someone used that was not as good but worked for his little boat.

[NahanniV]

Some thoughts:

I would suggest moving toward NMEA2000.

A Nmea183/seatalk mux is quite expensive.
An alternitive might be: a Seatalk1 to/from NMEA2000 converter that is less than $100.

I did not see which AIS you are thinking of.
The Vesper xb8000 is expensive, but it combines several functions: Outputs GPS position, converts NMEA2000, multiplexes NMEA0183 to wifi and USB and is a low power WiFi router.

The 4G RADAR can only accept heading over simnet(NMEA2000), but it's not necessary; The current RADAR plugin only works in overlay mode and requires that OpenCPN is receiving heading and position (I think there will be a heading up/RADAR only mode soon).

Cheers,
JM.

[Dockhead]

Originally Posted by NahanniV

Some thoughts:

I would suggest moving toward NMEA2000.

A Nmea183/seatalk mux is quite expensive.
An alternitive might be: a Seatalk1 to/from NMEA2000 converter that is less than $100.

I did not see which AIS you are thinking of.
The Vesper xb8000 is expensive, but it combines several functions: Outputs GPS position, converts NMEA2000, multiplexes NMEA0183 to wifi and USB and is a low power WiFi router.

The 4G RADAR can only accept heading over simnet(NMEA2000), but it's not necessary; The current RADAR plugin only works in overlay mode and requires that OpenCPN is receiving heading and position (I think there will be a heading up/RADAR only mode soon).

Cheers,
JM.

It might be worth asking Navico for the definitive answer, but the 4G radar will not produce a radar overlay on a Zeus plotter if it is not getting its own heading data, even though the plotter is getting heading. I bet it will be the same with OCPN.

There are some calculations done right in the radar black box, including I think bearing to target and MARPA, which need heading data.

I certainly agree with your recommendation about migrating to N2K.

[Dockhead]

Originally Posted by rgleason

Thanks Dockhead. There was another sensor someone used that was not as good but worked for his little boat.

Any heading sensor will work to some extent, but to get decent radar overlay and MARPA you need the best you can afford -- difference is dramatic, and so even on a tight budget this is not a good place to economize.

Good, stabilized, heading data is important for your pilot, as well.

[NahanniV]

Originally Posted by Dockhead

It might be worth asking Navico for the definitive answer, but the 4G radar will not produce a radar overlay on a Zeus plotter if it is not getting its own heading data, even though the plotter is getting heading. I bet it will be the same with OCPN.

There are some calculations done right in the radar black box, including I think bearing to target and MARPA, which need heading data.

I certainly agree with your recommendation about migrating to N2K.

I don't think he is planning to have a navico plotter.
The RADAR plugin for OpenCPN will work with heading supplied to the RADAR or to OpenCPN (I have tested it). To the RADAR would be slightly better since the RADAR scan lines will have the heading added to them as they are received, but the difference is minimal.
There is no MARPA for OpenCPN and from your reports it seems that it is not even working well with the Navico plotter.

Cheers,
JM.

[rgleason]

This discussion is changing my nmea 0183 -centric concept of how to wire stuff. At this point all we have is simple slow nmea 0183 and Seatalk original. I have purchased a gadgetpoole seatalk- nmea link converter and will eventually want broadband radar, ais and seatalk instruments all connected, preferably with most of this on wifi. Mux are expensive. What config do you suggest would be best? I've been hoping that Standard Horizon will come out with a new VHF + AIS transponder + GPS which would simplify things in small boats. This should have nmea2000 and 0183 and usb port for pc.

[barnakiel]

AIS may require nmea RMC or similar and AIS may output gps dat or not, depending on your unit.

Wind ST60 requires heading and speed for true and (further up the chain for conversions between angle and direction). ST60 will not take nmea unless you wire thru their nmea/seatalk box.

Look at toys like Vespers blue box which combo many functions, output data and wifi it all. Plus it is a high IPX.

If you want to wifi much data then you are in for much interfacing (mind cost of all the usb / 232 / 422 converters ...) unless you are on one system /say SeaTalk or any other one standard equivalent)

As with anything else: keep it simple. I think forwrd looking (say going all N2K makes sense if you are looking beyond 5 years horizon.

b.

[fogmachine]

We have a mixed 0183/N2K environment bridged by a Vesper - overall it works well with a few nits.

The majority of our sensors, displays and the autopilot are on N2K. The chart plotter (and its GPS) w/ radar is on 0183. The Vesper provides GPS to the N2K side.

The Vesper bridges most N2K data to 0183 but not the other direction. So when we use the chart plotter for routing the N2K displays don't see its waypoint/nav data so they can't show useful information like bearing to waypoint, VMG, time to go, XTE, etc.

OpenCPN and SEAiq see the gatewayed data so they give great nav info (and AIS), but the laptop is usually below so it doesn't help the driver.

If/when Vesper (a great piece of kit) updates the firmware to gateway waypoint data to N2K then all will be seamless. Perhaps they'll go further and offer the N2K data as JSON for SignalK, too. Replacing the chart plotter with an N2K unit would also improve things plus allow us to use OpenCPN radar overlays. Until then we're a little kludgey.

So if you're going to have a mixed N2K/0183 environment look at the bridge functionality in the docs from your chosen vendor - which sentences are translated in both directions - and make sure you'll end up with the right data where you expect it.

[Dockhead]

Originally Posted by NahanniV

I don't think he is planning to have a navico plotter.
The RADAR plugin for OpenCPN will work with heading supplied to the RADAR or to OpenCPN (I have tested it). To the RADAR would be slightly better since the RADAR scan lines will have the heading added to them as they are received, but the difference is minimal.
There is no MARPA for OpenCPN and from your reports it seems that it is not even working well with the Navico plotter.

Cheers,
JM.

Navico make the radar, which is why they might help him.

But if you have tested radar overlay in OCPN without heading supplied to the radar itself, then you have superior knowledge (actual observations versus speculation ), and this is really useful, and he won't need Navico tech support.

Concerning MARPA -- yes, in my experience, it's nearly useless, so no big loss if his system is configured without it.