windsensor for rotating mast, microPC needed for NMEA correction

[blubaju]

there is only a handfull companies, none of the "usual" big players, supporting rotating masts, but there are nice new sensors from airmarine and Maretron.

Both deliver NMEA sentences about wind data, the airmarine comes even with build-in GPS and compass. But this data must be corrected for the mast rotation, it could be done by a PC, but this is to much power input in the long run and might confuse the navigationPC when there are multiple NMEA processes running same time.
a small single board computer, even a 8088, something small and simple in a blackbox, should receive heading data from the mast and from ship compass and correct vor the rotation and then return the corrected wind direction and speed to the NMeA bus.

anyone who assembled like that alread?
Or who is capable of heliping out?
I and many others woul be happy to find help.

Henry

[labatt]

B&G has a wind sensor with built in support for rotating masts. You might want to give them a shout.

[sailingdog]

You're better off looking for something made specifically for rotating masts, rather than a much more complicated, and probably more expensive, cobbled-together system. Reliability will be higher and maintenance will be lower.

[EpicAdventure]

Do you think there is a market for a device the performs the conversion you are talking about?

It wouldn't take much to design up a little box that takes mast head wind and compass and ship compass and outputs the corrected version.

I'm guessing probably not as there doesn't seem to be many rotating masts.

[sailingdog]

Rotating masts are actually quite common on multihulls. Most Corsair trimarans have a rotating mast. The reason they're less common on monohulls, is that the engineering is a bit more complicated, and PHRF regs do not allow the use of rotating masts IIRC. Also, many monohulls are designed with keel-stepped masts, which eliminates the possibility of a rotating mast for the most part.

They already make gear that does this, but it is generally reserved for the racing market, on high-performance multihulls. For instance, you can see such a piece of gear at TackTick, which makes some nice wireless instruments for boats.

Epic- You wouldn't need to refer to the compass, but would need a sensor on the mast that tells you what the current angle of rotation of the mast is...so you could offset the wind sensor readings... this is how the gear from TackTick works IIRC.

[blubaju]

Hi Epic, depends how conservative the sailors are where you are, Aussies have quite a lot of rotating mast on their multihullsmany end up with a home build carbon cheaper than a factory supplied Alu spar.

I know of B&G (a converted rudder sensor, to be mounted exactly inline and protected!!! sounds a little bit odd on that place)

nke, good but far beyond my financial capabilities, but maybe our importer wants to become very rich very fast, my quote was twice as high as any else

technautic, just places a simple potentiometer, protected and mounted to your own choice. hm, but the instruments look like developed in the late fifties

Silva, my favourite, has a standard windsensor plus a second compass mounted on the mast, both are connected to what i suggested, a small blackbox, but the output is the corrected analog signal for their server.

Ticktack: this little device looks very much like a small fluxgate as it sticks on the mast only with no mechanics connected. I do not like them as I do not want to change LiIon Batteries all the time, I consider this very unnessesary pollution and wasting of my money. That I do not like their design is another point.

In any of these product line, you got to bu the whole system same brand.

Designs I like: Smart sensors for wind, log and depth and whatever, might be extended to a NMEA200 system once including engine controls etc., and a few Multi instruments, style well look at Simrad or similar ;-))

why I suggest and want this system:

The new intelligent wind sensors of Airmar and Maretron are calling for it. their output is already NMEA, Maretron even simultanly delivers NMeA2000 and NMeA 0183. If this NMEA wind-output is corrected, then you are free to use what ever instrument system of whatever brand as all permit NMEA input. Or you might go without any instruments and use a PC, or some other multi purpose plotters know. Have a look at again SIMRAD Glassbridge (beyond my finances :-( or Northstar etc)

I can do it with my PC and a small basic program, it is easy, NMEA specifications are public, but I am not familiar and do not want to start studying single board micro processors in for me unknown languages. Second, it might be a little confusing for my PC having one programm crunching 2 NMEA listeners and sending out the wind data to the NMEA bus, then same time accepting NMEA in for the navigation system and putting out the data for the autopilot. Might be confusing for everybody else when looking for a fault and at last - not least - if the PC is off, you still want a correct signal from the wind instruments, saves a lot power when the PC is off ;-))

There might not be such a huge market, but someone who likes for instance Raymarine could go with one and no one ever sees there is a different wind sensor.