Sending WPT and Routes to Nasa Clipper Repeater

[Frankiez]

Hi everybody,

my name is Frank, I´m from Germany and I´m new here.
As always you join a forum when you have a problem.
This is my one:
Is it possible to connect a Laptop with XP and OpenCPN to a repeater, say NASA Clipper for instance and if yes, how???

And stay simple please, I´m not a professionell computer-user

Thanx alot

[alex2035]

If you mean the NASA Clipper GPS repeater, yes you can, it has a standard nmea interface. But you can actually see the active waypoint/route, there is a difference between a repeater instrument and one that can actually get all your waypoints and routes from the PC, that is for example a chartplotter. I dont see NASA Clipper has one.
regards.alex

[Zorg]

Hello,

I am new too on this forum but i use OCPN since april of this year. My issue is about NASA Clipper GPS repeater installed on my boat, it needs RMB, RMC and GSA NMEA sentences. If i well read the OCPN manual only RMB and RMC sentences are send out to com port for autopilot needs, is it right ? is there an other way to send out the 3 sentences needed by Clipper GPS repeater ?
Thanks and regards.
1

[alex2035]

GSA is number of satellites and DOP as in this NMEA document:
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GSA - GPS DOP and active satellites. This sentence provides details on the nature of the fix. It includes the numbers of the satellites being used in the current solution and the DOP. DOP (dilution of precision) is an indication of the effect of satellite geometry on the accuracy of the fix. It is a unitless number where smaller is better. For 3D fixes using 4 satellites a 1.0 would be considered to be a perfect number, however for overdetermined solutions it is possible to see numbers below 1.0
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The only way is connecting a nmea multiplexer, a box that has multiple nmea inputs and multiple outputs. Because you will have to take GSA from the GPS signal and because there can only be one "talker" in a system, with the box you make one output from multiple sources of data. for practical purposes RMC and RMB will be sufficient I think, that would mean you really have a position, no need to get GSA but I understand if you do. best regards. alex

[Zorg]

Thanks Alex,

You'll find hereunder an extract from the NASA GPS repeater manual :
"The GPS repeater offers full functionality only when the GPS receiver is setup to send NMEA 2.0 (or latter) messages at 4800 baud. NMEA messages types RMB, RMC and GSA, are required to fullfill all the repeater's functions."
Without GSA it does'nt work.

I understand your point :
RMB coming from OCPN electronicaly (box) multiplexed with GSA and RMC coming directly from the GPS.
But is'nt it possible for OPCN to send RMC and GSA received from the GPS along with calculated RMB from the active route ? I think NavmonPC is able to do that.
It seems that RMC has been added recently to sentences send to the autopilot.

Regards1

[alex2035]

GSA is not available over OpenCPN AP output , perhaps you can try this, at your own risk:

derive the output of the GPS going to the PC to nmea in on NASA, so you end up summing GPS output + OpenCPN output. It could work, I have done this where there is no multiplexer and "sometimes" it works, as long as the "talkers" dont speak the same sentences. So GPS outputs RMC and GSA (transit data and satellites) , OpenCPN talks RMB (an active waypoint-route) Dont put RMC over OCPN Autopilot output. It is OFF by default.

best luck. alex