NMEA GPS Receiver Recommendation

[Daverw]

My friend has just added AIS to his chartplotter, unfortunately this means the the single nmea port has to be set to 38400, the chartplotter used to feed the DSC radio but now cannot.

Simple option looks like to add NMEA GPS receiver, any thoughts and recommendations?

 

[lw395]

Would one of these work?
https://www.ebay.co.uk/itm/Ublox-NE...149673?hash=item4b4e1e34e9:g:n1UAAOSw~RFa5LVs

It might need a level shifter for the NMEA?

 

[pvb]

My friend has just added AIS to his chartplotter, unfortunately this means the the single nmea port has to be set to 38400, the chartplotter used to feed the DSC radio but now cannot.

Simple option looks like to add NMEA GPS receiver, any thoughts and recommendations?

Simple standalone GPS receivers can be found easily, with 4800 baud connectivity. The Evermore SA-320 is often recommended, but JG Tech have a similar one for £79 - https://jgtech.com/GPS-Aerials/Other/Marine-GPS-4800-baud.html

You haven't specified whether your friend has added an AIS receiver or an AIS tranceiver. If the latter, before buying a separate GPS receiver, check whether it will output the GPS position at 4800baud (some can).

If he wants to fiddle around with voltage converters, etc, there are some other cheapo alternatives, but they might be too much hassle for him.

 

[Daverw]

He has added a transceiver but unlike mine that has 2k and 2nmea 0183 his only has one NMEA 0183 input/output, also the chartplotter Lowrence has 2k and single 0183 input / output.

As far as cheapo options I would suggest to him to keep it simple.

We did look at using 0183 to 2k converter it the costs were higher and he is not planning of changing other stuff to 2k so no real advantage to him.

 

[pvb]

He has added a transceiver but unlike mine that has 2k and 2nmea 0183 his only has one NMEA 0183 input/output

That sounds rather basic, which transceiver did he get?

 

[Daverw]

It’s an older Comar CSB200, it lists single RS422 output and a single RS232 output, later models seem to have added a second 0183 port

 

[pvb]

It’s an older Comar CSB200, it lists single RS422 output and a single RS232 output, later models seem to have added a second 0183 port

Hmmm... not cheap either.

 

[RichardS]

My friend has just added AIS to his chartplotter, unfortunately this means the the single nmea port has to be set to 38400, the chartplotter used to feed the DSC radio but now cannot.

Simple option looks like to add NMEA GPS receiver, any thoughts and recommendations?

I was in exactly the same situation and bought a used multiplexer on eBay for £50. Easy to connect up and works well.

Richard

 

[rszemeti]

He has added a transceiver but unlike mine that has 2k and 2nmea 0183 his only has one NMEA 0183 input/output, also the chartplotter Lowrence has 2k and single 0183 input / output.

If he has added a Class B AIS transciever then the transciever will already have a built-in GPS, as that is part of the Class B specification, so it must have an internal GPS reciever to be compliant.

If the AIS is not passing the GPS data as NMEA snetences on it's output, maybe check the configuration.

 

[pvb]

If he has added a Class B AIS transciever then the transciever will already have a built-in GPS, as that is part of the Class B specification, so it must have an internal GPS reciever to be compliant.

If the AIS is not passing the GPS data as NMEA snetences on it's output, maybe check the configuration.

The OP's friend wants GPS data at 4800baud to feed into a DSC radio.

 

[rszemeti]

Infact, just checking the spec on the Comar 200B, it does indeed have its own built-in GPS receiver, so connect an aerial to that, and you should get combined AIS data and GPS data coming down the NMEA 38.4kbd cable to the chartplotter, so no need for any additional GPS or other port.

 

[pvb]

Infact, just checking the spec on the Comar 200B, it does indeed have its own built-in GPS receiver, so connect an aerial to that, and you should get combined AIS data and GPS data coming down the NMEA 38.4kbd cable to the chartplotter, so no need for any additional GPS or other port.

See post 10....

 

[rszemeti]

See post 10....

Ah yes, mea culpa.

A common problem, my AIS receiver has 4800 baud in, and 38.4 and 4800 out .. AIS data only appears on the 38.4 port, but the GPS (and any other) data is repeated on the 4800 port as well, as a pass-thru.

 

[Daverw]

He did buy it at a good reduced price, however it will now not be so good. He was going to get a Digital Yachts AIT2000 the same as I’ve got and this can send out two individual nmea speeds

 

[DAVAIS]

You can always use a multiplexer to combine inputs and adjust the baud rates. Quark has one which support WiFi output, I found its very helpful. https://www.quark-elec.com/product/qk-a031-nmea-0183-multiplexer-with-seatalk-converter/ Unfortunately, it doesn't support bi-directional on USB and WiFi which means autopilot cannot works with it.

 

[pagoda]

Would one of these work?
https://www.ebay.co.uk/itm/Ublox-NE...149673?hash=item4b4e1e34e9:g:n1UAAOSw~RFa5LVs

It might need a level shifter for the NMEA?

We have a standalone TTL GPS device feeding the boat CPU (plotter has it's own)
It's a UBLOX 8 device which defaults to 9600baud, but can readily be re-set to 4800 using the manufacturers free configuration software "U-Center". It runs on 3.3 to 5V DC so all that is needed is a 12>5V regulator.
Level shifting does not appear required since NMEA at 5V TTL levels works fine. You can put the 12VDC 5VDC converter and the GPS in a small project box out of sight. Only 3 wires required Power+ , ground and NMEA+ out at 4800.
Total cost about £20

 

[dolabriform]

He has added a transceiver but unlike mine that has 2k and 2nmea 0183 his only has one NMEA 0183 input/output, also the chartplotter Lowrence has 2k and single 0183 input / output.

As far as cheapo options I would suggest to him to keep it simple.

We did look at using 0183 to 2k converter it the costs were higher and he is not planning of changing other stuff to 2k so no real advantage to him.[/QUOTE

Is there anyway of setting the NMEA output on the Lowrance to 4800 and connecting that to the VHF?

 

[Daverw]

Unfortunately both input and output have to be the same baud

 

[DAVAIS]

Any suggestions on 12V/5V dc converter? had one from Ebay but very hot and eventually dead.

 

[dolabriform]

Any suggestions on 12V/5V dc converter? had one from Ebay but very hot and eventually dead.

Here ya go:
https://uk.farnell.com/xp-power/tr10s05/dc-dc-converter-5v-1a/dp/2708277