Seatalk to nmea conversion.

[wiggy]

Anyone know how to make one of these, they seem awfully expensive to buy.

 

[Otter]

Just explain the application - all Raymarine autopilots and some control heads do this without add on items.

 

[AngusMcDoon]

Anyone know how to make one of these, they seem awfully expensive to buy.

You need a Seatalk hardware interface and a small processor to interpret the Seatalk messages and write out the NMEA messages via a RS422 line driver. A PIC processor will do, for example 18F24K22. You could also use an AVR, Arduino or a small ARM. Or just about anything else from PDP-11 onwards. Components would be less than £5 even at retail one-off prices.

Seatalk is explained here...

http://www.thomasknauf.de/seatalk.htm

I could do it, but it's been done by plenty of other amateur tinkerers already. You could use my Seatalk to USB as a starting point, just rip out the USB stuff (i.e. most of it) and add in writing to a standard UART.

 

[AngusMcDoon]

If I get enough votes I might do it and make a kit. The Seatalk to USB YAPP has been the most popular. I posted it ages ago but get regular requests for details. It would be easy enough to make a kit that does USB and NMEA.

 

[stephencox]

I for one would be very interested in a kit that does USB and NMEA.

 

[Doineann]

Which seatalk and which nmea? It makes a big diference to the answer.

For example, Seatalk ng and nmea 2000 are as good as the same, so get a seatalk wire, cut the socket off and wire in an nmea 2000 field fitting and bob's your mother's brother

 

[prv]

Which seatalk and which nmea? It makes a big diference to the answer.

When people don't specify, they almost invariably mean NMEA 0183 and the original Seatalk as used by ST40/50/60 instruments.

Pete

 

[stephencox]

That was my assumption and requirement. NMEA 0183 and the original Seatalk (or Seatalk1 as Raymarine now refer to it).

 

[Jabamusic]

I can hear Angus sharpening his pencil as we speak.....

 

[superheat6k]

If you can find one the older ST50 Tri data plus converts Seatalk to NMEA0183, note NOT ST60.

 

[Andrew G]

It depends a little what you want to do with it - if you want to input 3-wire SeaTalk(1) and get all relevant sentances as NMEA(0183) on USB with full commercial support you my need a commercial product. If you want SeaTalk(1) to NMEA (0183) on USB for input to say OpenCPN or MaxSea then Angus' YAPPs are great - I wont speak for him of course.
I have written code for myself that is SeaTalk(1) to RS232 to WiFi to my iPhone it displays SeaTalk data to the iPhone as text and graphs - it requires the PC to be running. It would be all care (little) responsibility. I (think) I've attached two snapshots from my phone. I should add that it also works as an auto pilot control - the buttons on the phone work and send SeaTalk commands to my system. Andrew