Request for NMEA sentences for GPSout

[dfournie]

Pete, I have two requests. 1) Would it be possible for the GSA sentence output from GPSout to get additional info added to it? Right now it has just enough of the fields filled to get a mapping program to recognize it and make use of it. According to the NMEA spec it has the active satellites available along with fix type (2D/3D), and accuracy info. The info I would like it to output does not need to be updated dynamically ie. the same GSA sentence can be sent out again and again as it is now with all the fields filled. 2) Along those same lines, could a choice be added for GSV sentences? Normally this sentence lists the satellites, their azimuth, elevation, signal to noise ratio, etc... Once again this data would be static and just sent as the others are. I can give you the complete sentences with the appropriate fields and checksums, if you deem this request worthy.

[Pete Dowson]

Would it be possible for the GSA sentence output from GPSout to get additional info added to it? Right now it has just enough of the fields filled to get a mapping program to recognize it and make use of it. According to the NMEA spec it has the active satellites available along with fix type (2D/3D), and accuracy info. The info I would like it to output does not need to be updated dynamically ie. the same GSA sentence can be sent out again and again as it is now with all the fields filled.

But filled with what, and why?

Along those same lines, could a choice be added for GSV sentences? Normally this sentence lists the satellites, their azimuth, elevation, signal to noise ratio, etc... Once again this data would be static and just sent as the others are. I can give you the complete sentences with the appropriate fields and checksums, if you deem this request worthy.

Well, I can't tell if it is worthy. If you can explain the point of such fixed fictitious data then, yes, of course I will consider it -- if you provide the exact data it will be easy enough. I don't actually need checksums, they are calculated dynamically.

Regards,

Pete

[dfournie]

These would work fine:

$GPGSA,A,3,07,08,11,13,28,29,,,,,,,2.0,2.0,2.0*3F

$GPGSV,2,1,06,07,31,214,44,08,82,021,51,11,31,102,44,13,08,176,36*75

$GPGSV,2,2,06,28,61,304,49,29,28,305,44,,,,,,,,*7F

Explanation: Your current GSA sentence is technically correct, but is not representative of a real world GSA sentence. It appears there is just enough info in your GSA sentence to get most mapping programs to accept it. The one above basically says you have a 3D fix, with DOP's of 2.0, and have 6 sats available. The smaller the DOP numbers, the better quality of the fix. I would like lower DOP's than the current GSA sentence allows (All 3.0), and having 6 sats is much more realistic for a true 3D fix.

The two GSV sentences above refer to the individual satellites in view (listed in the GSA sentence); giving each's azimuth, elevation, and signal to noise ratio. There can be as many as 3 GSV sentences in a row depending on the number of Sats the GPS "sees". The six satellites from the GSA sentence fit in the 2 provided. These would normally change as sats move around and drop in/out of view. The static one's above would be just fine. Two of my mapping programs require both GSA and the appropriate GSV sentence(s). I would assume the checksum would be generated by your code and tacked on the end of each sentence.

Possibly have the ability to choose to have the GSV sentences in the output as are currently the chices for RMC, RMA, GGA, etc...

[Pete Dowson]

These would work fine:

$GPGSA,A,3,07,08,11,13,28,29,,,,,,,2.0,2.0,2.0*3F

$GPGSV,2,1,06,07,31,214,44,08,82,021,51,11,31,102,44,13,08,176,36*75

$GPGSV,2,2,06,28,61,304,49,29,28,305,44,,,,,,,,*7F

Okay, easy enough.

Possibly have the ability to choose to have the GSV sentences in the output as are currently the chices for RMC, RMA, GGA, etc...

Actually, there's a GSV option already in there -- has been for a long time. Just seems to have missed mention in the docs. Sorry. Here is what it would have provided:

$GPGSV,1,1,04,01,45,000,50,02,45,090,50,03,45,180,50,04,45,270,50

Anyway, I attach test version 2.581 which includes the above values. See if that meets your needs.

Regards,

Pete

GPSout2581test.zip

[dfournie]

Many thanks Pete. I tried the built in GSV with ver 2.57 and it really does work. Much like the GSA in 2.57 it contains just enough to make a mapping program accept it as valid. The three sample sentences I provided, that you included in build 2.581 also worked fairly well. Unfortunately the ones I provided, happen to have had poor satellite geometry in the sky. Sorry about that. These sentences below have 9 satellites and give a much better "view" of the satellites being used for the position calculation. Along with very good DOPs.

$GPGSA,A,3,10,28,24,04,09,02,07,30,05,,,,1.4,0.9,1.1*31

$GPGSV,3,1,09,02,73,184,50,04,53,052,50,09,50,245,50,05,45,318,52*7F

$GPGSV,3,2,09,07,24,065,49,24,12,040,49,30,10,311,49,10,08,162,49*7F

$GPGSV,3,3,09,28,02,123,49*45

[dfournie]

My bad, Pete. Please ignore the previous post with the newer GSA and GSV sentences. They were goofed up. Honest to goodness, this one is right. Sorry for the inconveinance.

$GPGSA,M,3,10,06,04,09,02,07,30,05,,,,,1.6,0.9,1.3*3B

$GPGSV,2,1,08,05,77,295,51,02,69,033,50,30,39,315,49,10,36,141,49*7B

$GPGSV,2,2,08,09,25,213,49,04,23,044,49,06,17,287,49,07,05,089,49*74

[Pete Dowson]

$GPGSA,M,3,10,06,04,09,02,07,30,05,,,,,1.6,0.9,1.3*3B

$GPGSV,2,1,08,05,77,295,51,02,69,033,50,30,39,315,49,10,36,141,49*7B

$GPGSV,2,2,08,09,25,213,49,04,23,044,49,06,17,287,49,07,05,089,49*74

"Groan". :wink:

Attached 2.581.

Pete

GPSout2582test.zip

[dfournie]

Thank you Pete. It works very well. The only thing I see wrong is the checksum being generated for the 2nd GSV sentence. It's supposed to be 74, but it seems to be coming out of MSFS as 73. The sentence is rejected by my map. I've checked it twice and keep getting 74 as the correct checksum.

Here's the 2nd GSV sentence from latest gpsout.dll 2.581:

$GPGSV,2,2,08,09,25,213,49,04,23,044,49,06,17,287,49,07,05,089,49*73

Here's the same 2nd sentence coming from a real GPS:

$GPGSV,2,2,08,09,25,213,49,04,23,044,49,06,17,287,49,07,05,089,49*74

They are exactly the same except for the checksum at the end.

You don't need to fix it if you don't want. I don't want to trouble you anymore. If you do want to fix it, that's fine too.

[Pete Dowson]

Thank you Pete. It works very well. The only thing I see wrong is the checksum being generated for the 2nd GSV sentence.

Strange. I don't insert the checksum, that goes through a routine to generate it. Maybe I didn't re-initialise it for the second sentence of the same type, though in that can 2.581 should have been wrong too.

[Later]

Yes, there was a statement missing. The sum provided was including the complete preceding GSV too. The same applied to the previous one I sent -- most odd that it didn't fail.

Try 2.583 attached. Sorry, I've not had time to test any of these myself.

Pete

GPSout2583test.zip

[dfournie]

Don't touch a thing!!!! It works perfectly. Thank you VERY much for the assistance. I appreciate your work.