Seatalk - NMEA0183 instruments

GraemeS

Well-Known Member
Joined
16 May 2012
Messages
143
Location
Midlands / Plymouth
Visit site
I know this subject has been done nearly as many times as anchors and I really have read through lots of old threads trying to sift the wheat from the chaff so to speak.

I have on my boat (none of which are connect to each other) Garmin GPS 128 with NMEA0183, Nasa Clipper wind instrument with NMEA0183, echo pilot log and depth with NMAE0183 and tiller pilot ST2000 (old black casing) with Seatalk only.

How do I and what do I need to get them talking to each other? I'd like to use 'opencpn' too but I do tend to navigate with charts and so would not use the pc all the time. The priorities for me are to be able to integrate the auto helm so that I can sail by wind direction and to next waypoint under motor. It would be nice though to have the data from all instruments go to the pc as well. In time I'm like to add AIS.

If anybody has the time to explain to me in simple terms what I need to achieve this I'd be very grateful. Many thanks in advance. Graeme
 
I'm sure an expert will be along. On my boat the E85001 connects a non raymarine GPS to the autopilot. All my other instruments are raymarine. Sorry that I can only be of limited help.
 
None of the instruments will "talk to each other" as such, though each will emit its own data. Personally I'm not sure I'd bother changing such a setup - I'm happy to let the autopilot steer a straight line and adjust its course manually if wind or navigation require it - but if you really want to steer to wind or waypoint then I suppose you need an NMEA multiplexer that will combine the GPS and the windvane data into a single stream, and then a Seatalk bridge that will convert it to Seatalk.

Pete
 
GraemeS,

I have an old, at least 6 years old, E85001 in the garage, I'm not sure it still works, but you can have it for the cost of the postage and a bob or two into an RNLI box next time you pass one.

You could experiment with it, I used it to get NMEA 183 data into an old Autohelm tiller pilot.

PM me if you are interested.
 
GraemeS,


I have an old, at least 6 years old, E85001 in the garage, I'm not sure it still works, but you can have it for the cost of the postage and a bob or two into an RNLI box next time you pass one.

You could experiment with it, I used it to get NMEA 183 data into an old Autohelm tiller pilot.

PM me if you are interested.
PM sent thank you very much.
 
Thank you for your reply. Does that act as a multiplexer or don't I need to multiplex all the instruments? I thought NMEA0183 will talk to three units but only listen one, in which case how do you get the auto helm to listen to both the GPS and wind instrument or am I missing something fundermental?

Nope, you've got it pretty much correct. NMEA0183 is very restrictive - really just designed for point-to-point communications between two devices, though the output drivers can source enough current for one device to drive several others - but it is a one way thing - they cannot all see each other.

To simply get your autopilot to get input from both the GPS and the wind sensor, you need a basic NMEA0183 multiplexer - that Raymarine device will do it - at a price - if you are able to wield a soldering iron, they the YAPP guys will have a much cheaper solution.

You also mentioned AIS in the original message - that is a rather different question. Although they do usually support NMEA0183 protocol, they all run at far higher speeds than standard NMEA0183 instruments. Trying to combine AIS with speed, depth and gps will be far more complex and there are few devices around that could make any sense of a data stream containing such a mixture.
 
Thank you all for your inputs. I think I'm going to in the first instance try getting the wind instrument working with the pilot via seatalk to NMEA device Ian has very kindly offered. Then if that works I will see about connecting the gps. The AIS was an extra and so can wait too.

I have seen Yapp mentioned a few times so maybe I'll email them. I can solder after a fashion!

Thanks again all.
 
I found that with nasa wind and a newer st1000 autopilot that accepted nmea0183, thatbthe nasa gave one type of wind sentence and the raymarine only accepted the other, so it didnt work. If the adapter works then pls let me know.
 
Top