How to convert NMEA 0183 from high to low baud rate (without AIS info)?

[Plevier]

How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk 1?

This is a follow on to my post "NMEA head scratcher" http://www.ybw.com/forums/showthread.php?433872-NMEA-0183-head-scratcher in the hope of extra responses to a more specific question.

I have an NMEA 0183 output (RS422) at 38,400 baud. It does not include AIS info, just normal nav stuff - position, WPT, XTE, BTW etc. I can in fact select and minimise the sentences included. I need to convert it to 4800 baud to feed instruments and DSC radio. Alternatively conversion to SeaTalk 1 would be just as good.

The only commercial solutions I'm finding at the moment are multiplexers at approaching £200 which seem gross overkill for the job and are out of current budget.

Hoping someone has a simpler solution otherwise my nice new plotter will have to go back in the next day or two as incompatible! :disgust:

I'm OK on old fashioned electronics but not up with Arduinos, Raspberries etc.

 

[GHA]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

This is a follow on to my post "NMEA head scratcher" http://www.ybw.com/forums/showthread.php?433872-NMEA-0183-head-scratcher in the hope of extra responses to a more specific question.

I have an NMEA 0183 output (RS422) at 38,400 baud. It does not include AIS info, just normal nav stuff - position, WPT, XTE, BTW etc. I can in fact select and minimise the sentences included. I need to convert it to 4800 baud to feed instruments and DSC radio.

The only commercial solutions I'm finding at the moment are multiplexers at approaching £200 which seem gross overkill for the job and are out of current budget.

Hoping someone has a simpler solution otherwise my nice new plotter will have to go back in the next day or two as incompatible! :disgust:

I'm OK on old fashioned electronics but not up with Arduinos, Raspberries etc.

An arduino mega has 4 serial ports and *should* be able to do it..

http://forum.arduino.cc/index.php?topic=120931.0

Just one of many on ebay..

http://www.ebay.co.uk/itm/like/1308...3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108

 

[Boo2]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

Might the AMEK NK-80 work : http://www.scubastore.com/scuba-div...6&country=uk&gclid=CJ6V9pWtoMYCFerjwgod6RIA4g ? It's half the price of the NMEA muxs and should permit the AIS from your receiver to be sent to the chartplotter over NMEA200 leaving the NMEA183 ports free to run at 4800 baud.

Panbo mentions it here : http://www.panbo.com/archives/2012/08/amec_nk-80_0183n2k_adaptor_and_milltechs_7th_year_of_ais.html and the manual can be downloaded from here http://www.google.com/url?sa=t&rct=...4ETH-n18FV3WhYyqyZ1D9ew&bvm=bv.96339352,d.ZGU

<Edit : That Lowrance CP looks like exceptional value at £550, 9" and excellent chart support. I can see why you are reluctant to give up on it without a struggle.>

Hth,

Boo2

 

[Plevier]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

Might this work : http://www.scubastore.com/scuba-div...6&country=uk&gclid=CJ6V9pWtoMYCFerjwgod6RIA4g ? It's half the price of the NMEA muxs and should permit the AIS from your receiver to be sent to the chartplotter over NMEA200 leaving the NMEA183 ports free to run at 4800 baud.

Panbo mentions it here : http://www.panbo.com/archives/2012/08/amec_nk-80_0183n2k_adaptor_and_milltechs_7th_year_of_ais.html and the manual can be downloaded from here http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CC4QFjAC&url=http%3A%2F%2Fwww.milltechmarine.com%2Fcustomer_center%2FAMEC_NK-80_Manual.pdf&ei=3nuGVceRO4ON7Qad-IPIDg&usg=AFQjCNFz44i4ETH-n18FV3WhYyqyZ1D9ew&bvm=bv.96339352,d.ZGU

Hth,

Boo2

Thanks Mike

However as I read it, this wouldn't just plug into the plotter's port, I would have to set up a n2k powered network wouldn't I?

 

[pvb]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

However as I read it, this wouldn't just plug into the plotter's port, I would have to set up a n2k powered network wouldn't I?

Yes, remember you'll need at least 3 T connectors, 2 drop cables, a power cable and a couple of terminators. Probably back up to £200!

 

[bedouin]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

I was pondering similar issues yesterday as I am about to upgrade my plotter, and dealing with legacy NMEA feeds is one of the issues - and in fact I was looking at the plotter you mention. In those circumstances I would in inclined to consider NMEA 2000 <> Seatalk 1 conversion but that looks pretty pricey too. What connection options does the EasyAIS have?

Any project that can convert low > high could also be configured to go the other way, but with a little more programming as you may need to filter/drop messages.

In the meantime if you find any hints of a Seatalk 1 <> N2K DIY project let me know

 

[Boo2]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

However as I read it, this wouldn't just plug into the plotter's port, I would have to set up a n2k powered network wouldn't I?

Yes, I think you are right, AIUI you need T-pieces and terminators at each end of the bus. You would also need to check whether the CP provides +12V into the NMEA2000 bus (I know the Raymarine e7 doesn't do this) and provide it externally if not. Does the CP come with a T-piece and/or terminator plug ? IIRC my e7 came with blanking plugs but not terminators. The price of networking stuff does mount up if you have to source it all...

Boo2

 

[Plevier]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

I was pondering similar issues yesterday as I am about to upgrade my plotter, and dealing with legacy NMEA feeds is one of the issues - and in fact I was looking at the plotter you mention. In those circumstances I would in inclined to consider NMEA 2000 <> Seatalk 1 conversion but that looks pretty pricey too. What connection options does the EasyAIS have?

Any project that can convert low > high could also be configured to go the other way, but with a little more programming as you may need to filter/drop messages.

In the meantime if you find any hints of a Seatalk 1 <> N2K DIY project let me know

My EasyAIS is an old one, only NMEA. I think they have a variety now.

 

[Boo2]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

. In those circumstances I would in inclined to consider NMEA 2000 <> Seatalk 1 conversion but that looks pretty pricey too

Yes, Pixmarine have the Raymarine E22158 for £96 inc, see here http://www.pixmarine.co.uk/seatalk-1-to-seatalk-ng-converter-kit but you would also need an adaptor cable from STng to NMEA2000, either Raymarine part A06045 or A06046 which are £30 from here : http://www.marinesuperstore.com/electronics/cables-and-accessories?brand=RAYMARINE Don't know whether the male or femal version is required.

That takes the price down to £130 plus the postage on the cable, still not cheap...

Boo2

 

[bedouin]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

Yes, Pixmarine have the Raymarine E22158 for £96 inc, see here http://www.pixmarine.co.uk/seatalk-1-to-seatalk-ng-converter-kit but you would also need an adaptor cable from STng to NMEA2000, either Raymarine part A06045 or A06046 which are £30 from here : http://www.marinesuperstore.com/electronics/cables-and-accessories?brand=RAYMARINE Don't know whether the male or femal version is required.

That takes the price down to £130 plus the postage on the cable, still not cheap...

Boo2

In fact if you take into account everything you get for your £99 that is not a bad deal - I am thinking of going that way to interface a new Raymarine plotter (e.g. A75) to the old ST4000+ autohelm rather than trying to squeeze it on to NMEA - of course the one thing I can't know for certain is whether when I've done it all the sentences end up where I want them - e.g. will the Wind data pass from NMEA 0183 in on the plotter to Seatalk out?

To the OP - have you considered changing some of your hardware? Might be cheaper to replace for example the EasyAIS with one that works on N2K rather than go to all the cost and complexity of trying to change rates and so on.

FWIW I have been shopping around for a VHF that includes AIS and has N2K (e.g. Simrad RS35) to solve some issues.

 

[Plevier]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

To the OP - have you considered changing some of your hardware? Might be cheaper to replace for example the EasyAIS with one that works on N2K rather than go to all the cost and complexity of trying to change rates and so on..

It had occurred to me but an n2k AIS rx plus the n2k backbone stuff again would come out pretty dear.
Idon't imagine the Matsutec AIS transponder has an n2k output? That would be tempting - but over budget again.

 

[Plevier]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

Yes, Pixmarine have the Raymarine E22158 for £96 inc, see here http://www.pixmarine.co.uk/seatalk-1-to-seatalk-ng-converter-kit but you would also need an adaptor cable from STng to NMEA2000, either Raymarine part A06045 or A06046 which are £30 from here : http://www.marinesuperstore.com/electronics/cables-and-accessories?brand=RAYMARINE Don't know whether the male or femal version is required.

That takes the price down to £130 plus the postage on the cable, still not cheap...

Boo2

That's a smart one. Gives some future proofing on the ST60 instruments and autopilot.
The E22158 kit, which converst ST1 to STng, plus the cable, would be everything would it?

I didn't think n2k and STng were totally compatible?

 

[pvb]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

The E22158 kit, which converst ST1 to STng, plus the cable, would be everything would it?

Sadly not, I think you'd still have to create an NMEA2000 system, so you'll need £100 or so of T-pieces, power cable, drop cable, terminators, etc.

 

[Plevier]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

Sadly not, you'd still have to create an NMEA2000 system, so you'll need £100 or so of T-pieces, power cable, drop cable, terminators, etc.

Why? Have I misunderstood something? The STng kit (you can buy just the convereter separately, but Boo2's link is this kit) includes

"Everything you need to convert Raymarine Seatalk1 to SeatalkNG and create a backbone.

Includes
2 terminators
1 Inline interface box
1 Power Cable
1 Drop Cable
1 ST1 to STNG Cable"

More detail at http://www.raymarine.co.uk/view/?id=1597

then the other cable

"Raymarine Devicenet Female A06045
Connects NMEA2000 devices to a SeatalkNG network"

 

[pvb]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

Maybe, just maybe. Depends what the Lowrance is looking for. Can you ask John at JG Tech? He knows his stuff.

Wouldn't all this be much easier if Raymarine had never introduced their various generations of SeaTalk, designed only to trap people into having to buy Raymarine kit?

 

[bedouin]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

Maybe, just maybe. Depends what the Lowrance is looking for. Can you ask John at JG Tech? He knows his stuff.

Wouldn't all this be much easier if Raymarine had never introduced their various generations of SeaTalk, designed only to trap people into having to buy Raymarine kit?

Yes - I seem to be descending into interface hell - ending up with a system with NMEA 0183, NMEA 2000, Seatalk1 and SeatalkNg (not to mention the old Navico Corus bus).

There must be an easier way

 

[Boo2]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

Why? Have I misunderstood something? The STng kit (you can buy just the convereter separately, but Boo2's link is this kit) includes

"Everything you need to convert Raymarine Seatalk1 to SeatalkNG and create a backbone.
...snip...

Yes, I think with the NMEA2000 to STng cablke adaptor that is a complete backbone system as you say. Your CP should be a drop cable off the backbone and there should be no problems in theory. My understanding is that Raymarine is now using the pukka NMREA2K AIS messages whereas before they were not so it should work. Might be worth asking Lowrance what they think though, it's always a risk mixing kit from different manufacturers...

Boo2

 

[Plevier]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

Yes, I think with the NMEA2000 to STng cablke adaptor that is a complete backbone system as you say. Your CP should be a drop cable off the backbone and there should be no problems in theory. My understanding is that Raymarine is now using the pukka NMREA2K AIS messages whereas before they were not so it should work. Might be worth asking Lowrance what they think though, it's always a risk mixing kit from different manufacturers...

Boo2

The AIS would be on the 0183 port, Mike.

 

[Plevier]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

Yes - I seem to be descending into interface hell - ending up with a system with NMEA 0183, NMEA 2000, Seatalk1 and SeatalkNg (not to mention the old Navico Corus bus).

There must be an easier way

Absolutely!

Be sure to look at https://raymarine.app.box.com/s/p6alhxp7tter95anbgqa/1/1787231967/31974304017/1 for connection options! The ST1:STng converter has a 48 page manual!

 

[Boo2]

Re: How to convert NMEA 0183 from high to low baud rate (without AIS info) or SeaTalk

The AIS would be on the 0183 port, Mike.

Doh !

Boo2