NMEA speed to pulse converter

[rogerthebodger]

Here's an update for anyone interested in getting their cockpit speed through the water (STW) display to read SOG.

Cruzpro very kindly sent me one of their SOG2 devices to try. http://www.cruzpro.com/sog2.html

What can I say? It simply does what it says on the tin.
The GPS reception is good and both my Standard Horizon GX2100E and Netbook running OpenCPN had no trouble interpreting the NMEA sentences.

The pulse output at 22,000 pulses/nautical mile is 20% more than the NASA paddlewheel log delivers. All I had to do to make my Clipper Duet read correctly was reduce the Log calibration factor by the same amount.

I now have what I want. SOG in the cockpit with STW and SOG at the nav table.

Thats interesting.

I have just finished programming an Arduino nano to receive the RMC message from a GPS and convert it to the VHW NMEA message. I will be testing it out next time I go to my boat with my spare SImRAD IS11 speed display.

The later SIMRAD speed displays can read the RMC message direct to display either SOG or STW.

The GPS I use is the U blox unit from E-bay

 

[RichardS]

I now have what I want. SOG in the cockpit with STW and SOG at the nav table.

I assume that as you've read this thread you do realise that you haven't really got STW unless you have a real paddlewheel?

Richard

 

[Porthandbuoy]

I assume that as you've read this thread you do realise that you haven't really got STW unless you have a real paddlewheel?

Richard

I started the thread, so yes, I have read it.

Paddlewheel is connected to a NASA display at the nav station. SOG, thanks to the NMEA to pulse SOG2, in the cockpit.

 

[stuartsailor]

Old Thread... But we were never able to get the cruise pro to work with ST60. The cruise pro only had 2 out put wires and the RayMarine ITC-5 was asking for at least 3. Cruise pro referred us to this thread. Really no help in our situation. We also tried connecting via 0183 on SeaTalk1 side with no joy. The only goal is approximate TWS/TWA. It would be nice. If there was a SOG to STW nmea200 dongle we could get that onto the STNG network. cheers

 

[ithet]

I was programming an Arduino to do this but then NASA marine brought out their EML 3 electromagnetic log to pulse transducer unit. I have now fitted this which seems a much better solution for my ST60 as it still gives me real STW.

Not sure why you would be using an ICT-5 or NMEA connection to your ST60 input, you connect the pulse signal direct to the ST60 input pins.

 

[stuartsailor]

My Bad i60 replaced the ST60 system that died. the ICT 5 feeds the STNG. We have legacy ST60 Tridata displays and could not get the CruzPro SOG-2 gps to work using the depth or 0183 connections. CruzPro suggested a web search and offered no help on wiring. to bad because we thought the Cruzpro was a great option. We find that the only boats still installing paddle wheels are race boats. I like the EML 3 idea, does it work reliably? AirMar has not been able to make their version dependable after a decade. We used to use doppler logs from B&G but they were discontinued 20 years ago. Best log I ever had...

 

[ithet]

I have only just fitted EML 3 so don't know about reliability. However I held off fitting one until reports on here suggested some long term reliability. Search other threads, you should find my asking that question.