Getting NMEA 0183 Data to a Laptop via Raymarine S1 Autopilot

[night0wl]

Hi Everyone!

I have a Beneteau 343 that has a Raymarine S1 Wheel Pilot System with the ST6002 Head Unit, Raymarine C80 plotter, and Raymarine ST60+ instruments (Wind and Bi-Data) at the helm. I have wanted to have my pc at the nav station tie into my instruments for some time, so I thought I was on the right vein when I ordered a Raymarine NMEA interface box (E85001) as well as a long, 9m SeaTalk cable, and then a Raymarine Serial Cable (E86001). I already have a working RS232 to USB cable (with Windows 7 drivers).

The initial design thought was to install the NMEA interface box near my nav station. Then use the long SeaTalk cable and plug it into a spare port on a 3 way SeaTalk junction box inside my navpod thats already there at the helm. Then I'd use the E86001 serial cable to plug into the interface box and then the other port into my USB/Serial cable to the laptop.

All was well, until I saw some info where someone says that the S1 Corepack/Computer has a NMEA in and out already there. Sure enough, after tearing apart my boat to find where the computer was installed, I see that my S1 has boat NMEA in and out.

Now, I confused as how to get this all interfaced up to my pc. So my questions as follows:

1) Are NMEA 0183 in/out and RS232 effectively the same for the purposes of data transfer to a pc?

2) Can I simply use the E86001 serial cable to connect to the NMEA out of the S1 corepack? Then use a long, 25ft serial cable to connect to my laptop at the nav station?

3) If #2 is possible, do I absolutely need the E86001 cable to go from the S1 computer to be a pigtail of sorts? Or are there instructions to fashion my own cable to take from the NMEA out to a 9 pin (DB9) cable? Its a $20 for a 1 meter cable and if I can return it...why not.

Please let me know whatever advice the board has. Will try and post some pictures of the whole setup as I get this project going.

Much appreciated,

[night0wl]

So, an update.

I took the E86001 cable that had a Yellow, a Green, and 2 Black wires and connected Green to + output, 1 black to - output, then took the yellow to + input, and black to - input (I think, need to verify tonight) and voila...OpenCPN now sees GPS data on the wire.

However, I see no wind, sog, or other data at all. My only thought is that the autopilot head unit is not connected to this info...which is odd because it is able to see this info at the head unit (for example, steer to wind).

Any ideas?

[night0wl]

OK, I was able to solve this problem and put this project to bed this weekend. First, the obligatory OpenCPN shot of the whole thing working:



Despite my attempts to avoid it, I was forced to use the E85001 Interface box and the E86001 serial cable. I did not use the 9m Seatalk cable and that will be returned (more on that later).

Initially, I thought that the Smartpilot S1 was going to repeat all incoming data that came in through Seatalk onto the NMEA out. Unfortunately, it did not. It only sent Autopilot heading and GPS data on the NMEA out. So when my laptop was directly linked to the S1 via NMEA, all I was able to see was heading and GPS info. No wind, no SOG, etc.

So, I had to rig up the E85001 and use the 2 Seatalk ports on there. The first Seatalk was an input from my helm instruments. The second Seatalk was then routed to my S1 unit. This way, the Autopilot and the helm instruments were in communication on all wind, GPS, and other data needed to control my autopilot. Then, I used the RS232 output on the Interface to hook up to my laptop. For good measure, I rigged up the NMEA in to the laptop as well (the remaining two wires of the RS232). I was able to return the 9m seatalk cable since I realized that Seatalk to Seatalk via the Interface box to the S1 was just 3 wires and I had no need to use the proprietary Seatalk plug. So some shielded 3 wire and I was set to go.

Now, my challenge is routing the 40 ft serial cable to my nav station. I may not be able to fit those thick serial plugs through my conduit chases, but I realized I can certainly fit a looong USB cable. So from my laptop at the helm to my stern cabin (where all the Raymarine head units are), I will use a 50 ft USB Male to Female cable. Then plug in my USB to serial adapter to the female end of the cable. Then the female serial to the male serial part of the E86001 cable and that is plugged into the interface box....voila.

Lot more work than I thought it would be...but results are worth it.

[donradcliffe]

You will need an active USB cable if it is more than 5 meters long.

[AussieGeoff]

We have an ST6000+ in our boat. It's getting NMEA from the old Hummingbird NS10, but it also speaks Seatalk it seems.
Um, just to clear up a few things.
RS232 is the serial port hardware definition. NMEA is a data protocol.
So is SEATALK, though it's proprietary (not publicly released) to Raymarine.
It also runs on a different type of hardware, where NMEA is at a variety of baud rates from 4800 up to almost anything you like, SEATALK is fixed at 4800, but the differences are greater than that, as it is an asynchronous bidirection buss, not unlike ethernet in that it sends packets of data to the buss (+12v is 1, 0v is 0, slightly simplified) waits for a response and works around data collisions etc. It's not ASCII like NMEA (basically modified text) but binary (again, more like ethernet, or to use a GPS example, a bit like the Garmin binary (in concept only!).

I'm hoping to acquire an SL72Plus radar display and an intermittent SD18 radome very cheaply soon and it also speaks SEATALK and NMEA so hopefully they will all live happily together. I too have things like NROUTE on my laptop with BlueCharts so I plan to tap the NS10 for NMEA data to display on it - thinking about trying to get tracked targets and waypoints from the NS10 and SL72Plus to show up as well... I'd like to use OpenCPN etc instead, or even SeaClear, but alas there are no useful non commercial electronic charts of South Australian waters it seems.

There is at least one privately written overview of SEATALK by someone that basically reversed engineered it by monitoring the buss (presumably with a logic analyser at first) and working out what it did and how. It's possible to bridge SEATALK to an RS232 port (or indeed any serial port I suppose, including USB) and even do protocol conversion. They talk about the same things, just in different ways. I've seen one example of a very basic protocol converter using a PIC micro. It only converted one SEATALK command to NMEA (because it was the only one the guy needed) but the principle is sound and could doubtless be expanded, though I suspect Raymarine will chime in any moment and say that they'd want a license fee or something for messing with it.

AussieGeoff

[bewitched]

You touched on one of my pet hates of Raymarine and their ST series. When they say there is an NMEA output on a particular instrument, it doesn't necessarily mean that all the data that arrives at that instrument (via seatalk) is sent to the NMEA out port.

If you read the small print in the manuals you find out that various instruments output various NMEA data, but to capture all data in NMEA is a pain in the arse.

[Ziggy]

Originally Posted by night0wl

Now, I confused as how to get this all interfaced up to my pc. So my questions as follows:

1) Are NMEA 0183 in/out and RS232 effectively the same for the purposes of data transfer to a pc?

2) Can I simply use the E86001 serial cable to connect to the NMEA out of the S1 corepack? Then use a long, 25ft serial cable to connect to my laptop at the nav station?

3) If #2 is possible, do I absolutely need the E86001 cable to go from the S1 computer to be a pigtail of sorts? Or are there instructions to fashion my own cable to take from the NMEA out to a 9 pin (DB9) cable? Its a $20 for a 1 meter cable and if I can return it...why not.

Please let me know whatever advice the board has. Will try and post some pictures of the whole setup as I get this project going.

Much appreciated,

night0wl,

Sorry-this may now have been overcome by events, but you can find an excellent guide to NMEA0183 interfacing on Actisense.com: here.

By the way, NMEA0183 electrical specification is basically RS422, but it can very easily be interconnected with RS232.

[AussieGeoff]

Originally Posted by Ziggy

night0wl,

Sorry-this may now have been overcome by events, but you can find an excellent guide to NMEA0183 interfacing on Actisense.com: here.

By the way, NMEA0183 electrical specification is basically RS422, but it can very easily be interconnected with RS232.

You are in fact correct, something I hadn't realised, thank you!

AussieGeoff

[AussieGeoff]

Originally Posted by bewitched

You touched on one of my pet hates of Raymarine and their ST series. When they say there is an NMEA output on a particular instrument, it doesn't necessarily mean that all the data that arrives at that instrument (via seatalk) is sent to the NMEA out port.

If you read the small print in the manuals you find out that various instruments output various NMEA data, but to capture all data in NMEA is a pain in the arse.

You're quite right. I had a look at the radar I'm thinking of getting and it bridges only little of the Seatalk stuff to NMEA and vice versa.

I see no reason these days for everything not to be NMEA, particularly given that RS232 and particularly RS422 (which someone pointed out is actually the original electrical specification for NMEA devices) is useable over longer distances than SeaTalk, due to the higher swings between 1 and 0 (+15v for 1 -15v for 0, though most RS232 chips will take 1 as being anything over +5v and 0 as being anything from about +.1v to -15v) Plain vanilla TTL (+5v 1 0v 0) will be reliably read by most RS232 ports without modification, though trying to go the other way will likely destroy the TTL input gate.


AussieGeoff

[night0wl]

Im wondering if I want to get crazy and bring AIS into this party

That Matrix 2150 is looking very tempting, hehehe