NMEA data from my computer back to instruments.. is this possible?

[fuss]

I would like to have this option if it is possible, but I cannot seem to find any program or information on this.

Ideally the program would work like a virtual multiplexor on my pc. Maybe even allow some manipulation of the data. The data would then go out through a usb port.... i guess , then a usb cable with the nmea data could then be wired into any nmea in device.

Why would I want this...
To use a bluetooth gps as backup feeding to nmea instruments.
To have more than one depth transducer feeding nmea depth sentences.
To have some flexibility and control over the data if need be.

Thanks John

 

[Danny]

Check out GpsGate.

 

[nimbusgb]

No reason why this can't be done. Actually quite straightforward. You might need a port sharing package as well.

It would mean having the PC running all the time with the instruments so you'd need to consider power requirements. OK on a power vessel but what about sail?

Make it do seatalk too.

 

[Danny]

I just checked out the website and found it's rather confusing these days. The particular Franson product that might interest you is this. (No connection except as a satisfied user.)

 

[fuss]

Hi Danny,
Thanks very much, I have downloaded the demo and I am checking it out now.
John

 

[Refueler]

Many plotting programs on PC have what is called "Passthrough" - this is often user settable as well that you can decide what sentences pass through. Mostly used for Autopilots, so some programs limit the choice.

 

[qetoo]

I use Fugawi ENC on a laptop computer for navigation. A Garmin 128 is connected to input nmea 0183 to the laptop on the COM port. Fugawi ENC then sends out (echos) the following NMEA 0183 sentences coming from the Garmin 128 while it is not in an active route:
RMB, RMC, GGA, VTG, APB, WPL, and RTE.

When Fugawi ENC is on an active route, it sends out the following NMEA 0183 sentences:
RMB, RMC, GGA, VTG, APB.
These are sentences needed by the autopilot for steering to a course.

So probably wouldn't help echoing instrument data.

 

[Amphitrite]

Normally a nmea-multiplexer is good for the job, and those with PC-interface (USB or RS232) can send data to the PC and also re-distribute data received from the PC. A friend developed a tool for PC-based multiplexing, so if you definitely need this send me a PM.

Best regards

Holger

 

[Mrnotming]

I've downloaded the Standard version of Franson gps gate and found it worked so well I stumped up for a licence. Reason is AIS is planned and apparently there is a facility to blend two inputs and then regurgitate the stream over other virtual output com ports which can be multiple. Time will tell. Presently it has enabled a bluetooth remote gps on an Asus eeepc to connect to an older nav program by way of a lower number port being virtualised successfully. Good wintering to all in the freezing regions!

 

[Refueler]

[ QUOTE ]
Normally a nmea-multiplexer is good for the job, and those with PC-interface (USB or RS232) can send data to the PC and also re-distribute data received from the PC. A friend developed a tool for PC-based multiplexing, so if you definitely need this send me a PM.

Best regards

Holger

[/ QUOTE ]

A multi=plexor is a box that allows more than one TALKER to provide NMEA data without conflict. It is not a splitter.

As I understand it the OP wants to distribute data that originates from a PC based GPS. Passthrough will do that given a suitable plotting program such as Maxsea, Seaclear, Maptech etc. Once set-up you would just plug in other item to separate port on the PC designated as NMEA out.
If this is not possible then the Franson software is way to go. A Multiplexor is way overkill and unnecessary.

Of course the simplest way of all is to use a handheld or fixed GPS and then split the signal purely by connecting nmea cables in a simple junction box and feed to whatever you want. Even my little cheap eTrex basic will nmea to 4 items at least.
Here is how simple you can be :

A domestic small mains junction box with RS232 sockets fitted to side walls. Serial tail is to PC, works with serial to USB adaptor as well, then one imput from GPS, other is output to whatever you wish - in this case a HP Jornada PDA.

Another little project was to see if I could piggy back splitters and make connection simple ...

Yep - over counter screw terminal telephone wall socket. GPS is connected to the box via it's internal terminals and also recieves 12v. Other items such as PC whatever are then connected via standard telephone plugs. It's easy to determine contacts and then a simple telephone socket doubler will allow a second plug access etc. It works !
As you can see the telephone plug lead has been joined to a serial cable (cut from a failed mouse).

basically illustrating here that it's not necessary to breathe too much into NMEA science ... it's not hard, nothing complicated or expensive really needed. I used items from the scrap drawer and there you go.

My Lowrance GPS plotter has a RS232 9 pin plug permanently fitted to the leads so if anyone who comes on my boat wants NMEA - it's available. I can even plug into my PC or whatever if wanted. (I don't see a mulitplexor anywhere there !! /forums/images/graemlins/grin.gif )

 

[Danny]

[ QUOTE ]

If this is not possible then the Franson software is way to go. A Multiplexor is way overkill and unnecessary.

[/ QUOTE ]And even if a multiplexor is required Franson GpsGate will multiplex NMEA inputs and produce a combined output - or subsets of the input sentences - or both - or whatever. It'll do it on real (Serial, USB or Bluetooth) ports or 'virtual' ports (for your PC programs to use as input).

 

[Refueler]

[ QUOTE ]
[ QUOTE ]

If this is not possible then the Franson software is way to go. A Multiplexor is way overkill and unnecessary.

[/ QUOTE ]And even if a multiplexor is required Franson GpsGate will multiplex NMEA inputs and produce a combined output - or subsets of the input sentences - or both - or whatever. It'll do it on real (Serial, USB or Bluetooth) ports or 'virtual' ports (for your PC programs to use as input).

[/ QUOTE ]

As you will know as well - many times people say Multiplexor and in fact it's not what is needed. It does the job - yes - but is a way to spend money unnecessarily. If you only need one source of GPS data - then a simple splitter or passthrough is good enough. Passthrough depending again on plotting package used is not just data 'passed through' - it can in fact be PC based and stronger signal than GPS supplies meaning that more than 4 items can be supplied.....

 

[EdEssery]

Not sure if this is what you are driving at. TacticTool will read data out of your NMEA network display it on your PC and also do calculations upon it (time/distance to lay line, performance relative to polars etc.) and then, if you instruments can cope, it will output the results into the NMEA network for display on the instrument heads. Designed for use with TackTick and their NMEA transmitter. May work with other instruments as well.

I have downloaded the demo and am playing with it - seems pretty impressive.

No connection...

 

[Danny]

[ QUOTE ]
As you will know as well - many times people say Multiplexor and in fact it's not what is needed. It does the job - yes - but is a way to spend money unnecessarily. If you only need one source of GPS data - then a simple splitter or passthrough is good enough. Passthrough depending again on plotting package used is not just data 'passed through' - it can in fact be PC based and stronger signal than GPS supplies meaning that more than 4 items can be supplied.....

[/ QUOTE ]Absolutely agree with all that. Multiplexing only needed if you need to combine two or more NMEA 'talkers'. Multiple ports on the PC (either real ones or virtual via GpsGate) only needed if you are running more than one program requiring NMEA input.