Multiple NMEA inputs to PC for openCPN

sebastiannr

sebastiannr

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Hello all,

I inherited a yacht (High tension 36) last year, and soon I will have to move it from Crete to Lefkas. I am familiar with the boat as I sailed with my dad on it many times, but the electronics are far more advanced than on my own boat (Folksong 26), which comprised of no more than a GPS and depth sounder (not interfacing with each other!).

I want to use openCPN for AIS etc, but am unsure how to interface all the NMEA data from multiple intruments with my PC.

Any help would be greatly appreciated!
 
NMEA 0183 can only have a single talker, but can have multiple listeners. First you need to define what inputs your PC actually needs to have, because the fewer the better in many ways. If you have an AIS receiver it may already have a USB output for PC. If so that may do the job on its own if it outputs GPS data as well as AIS data, otherwise a USB GPS dongle may be required.

To gain some understanding of NMEA0183, go to this webpage and download the information sheet, the bottom download on the page. http://www.actisense.com/products/nmea-0183/nbf2/downloads-nbf2.html

Of course if your new boat has NMEA2000 instruments the system is totally different with all instrument data carried by a single bus.

If you need help connecting specific instruments to the PC post details of the makes and types, as someone here will have done it before.
 
sebastiannr said:
I want to use openCPN for AIS etc, but am unsure how to interface all the NMEA data from multiple intruments with my PC...
Click to expand...

If your instruments are NMEA 0183, then you don't need any expensive gear from Actisense, just a couple of RS232 to USB adaptors.

Beware the eBay cheap ones, the drivers caused many a BSOD on my PC. Both FTDI and Moschip chipsets are good.

I've got two of these, giving four inputs: http://www.amazon.co.uk/exec/obidos/ASIN/B0090EYCAG/dolcetto-21

If I were buying now I would get this type: http://www.amazon.co.uk/exec/obidos/ASIN/B0055CRAF6/dolcetto-21 as the COM port retention saves bother.
 
How many devices do you have needing NMEA data? (listeners) 2 or 3 should be ok without the need for a multiplexor. Just connect them all in parallel.
 
Spyro said:
How many devices do you have needing NMEA data? (listeners) 2 or 3 should be ok without the need for a multiplexor. Just connect them all in parallel.
Click to expand...

I don't understand this reply. My understanding is that the OP is intending having multiple devices producing data (his instruments), and one consuming data (his PC). If my understanding is correct then multiplexing is going to have to be done somewhere, either in Windows using XPort, or externally using a hardware device.
 
open cpn 3.2, the latest, can accept multiple com ports,

VSPE from erlogic is a useful extender, with the ability to have virtual ports etc.

Also franson gate do some tracking software etc, along with virtual ports and simulators.
 
Could this be of use ?

http://www.42.co.nz/freeboard/

I'm, planning to have a look at the ardunio board ?

Cheers

Stu

AngusMcDoon said:
I don't understand this reply. My understanding is that the OP is intending having multiple devices producing data (his instruments), and one consuming data (his PC). If my understanding is correct then multiplexing is going to have to be done somewhere, either in Windows using XPort, or externally using a hardware device.
Click to expand...
 
AngusMcDoon said:
I don't understand this reply. My understanding is that the OP is intending having multiple devices producing data (his instruments), and one consuming data (his PC). If my understanding is correct then multiplexing is going to have to be done somewhere, either in Windows using XPort, or externally using a hardware device.
Click to expand...

Yes that's the idea. I didn't realize multiplexing could be done in Windows - would the devices all have to be connected to the PC with separate cables?

Unfortunately XPort only supports 32bit windows, is there multiplexing software that can run in 64bit?

Thanks once again for all the replies.
 
david_bagshaw said:
open cpn 3.2, the latest, can accept multiple com ports...
Click to expand...
sebastiannr said:
I didn't realize multiplexing could be done in Windows - would the devices all have to be connected to the PC with separate cables? ...
Click to expand...

It isn't multiplexing as such, just that the PC gets data from several inputs, on separate cables. That's why I suggested: "a couple of RS232 to USB adaptors ...." in post #4. If you have two data streams, get one adaptor, if you have three or four, get two.
 
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