NASA Electromagnetic Log

[dolabriform]

Isn't there a YAPP which does this?

I could be wrong but from what I remember it does Seatalk to NMEA but not the other way round.

 

[Tintin]

Have had similar before ages ago, that time with NASA wind and a Raymarine autopilot.

Nasa outputs one type of nmea wind sentence, Raymarine only recognises another.

Not sure why Nasa can't sort this, they are small enough to fix it, unlike RM who don't care.

 

[AngusMcDoon]

I could be wrong but from what I remember it does Seatalk to NMEA but not the other way round.

It does both ways & supports messages VHW & VLW and Seatalk message 20h. I'm not making them anymore but the design & source code is available on GitHub.

 

[ithet]

There have been a couple of GPS SOG to pulse converter designs both here and elsewhere. It would just need a slight modification to use VLW instead of SOG.

 

[dolabriform]

It does both ways & supports messages VHW & VLW and Seatalk message 20h. I'm not making them anymore but the design & source code is available on GitHub.

Thanks for correcting me Angus. Is there an issue if anyone makes them?

 

[MikeCC]

Have had similar before ages ago, that time with NASA wind and a Raymarine autopilot.

Nasa outputs one type of nmea wind sentence, Raymarine only recognises another.

Not sure why Nasa can't sort this, they are small enough to fix it, unlike RM who don't care.

Indeed, that is correct. It may surprise people that NASA use the currently supported sentence whilst Raymarine use the deprecated one.

 

[Baggywrinkle]

Raymarine ST60 Log transducers

Update!

I have, after a bit if a struggle with the wiring, got the NASA transducer working with the ST60. It reacts to speed changes much quicker than the SOG from the GPS, and seems to be reasonably accurate. I need to calibrate it properly!

 

[AngusMcDoon]

Thanks for correcting me Angus. Is there an issue if anyone makes them?

Not at all. The license is MIT which means do what you like, make them, modify them, sell them - anything other than claiming the intellectual property is yours or prevent me from doing anything with it.