Support for NMEA 4.11

[f4grx]

Hi,

In recent GPS receivers like the ZED-F9P that I am fortunate to have, the GPS frames are multiconstellation.

As a consequence the useful messages are prefixed with GN and not with GP as in previous versions of the NMEA standard.

See here, page 24: https://content.u-blox.com/sites/default/files/documents/u-blox-F9-HPG-1.32_InterfaceDescription_UBX-22008968.pdf

$GP is only for GPS specific stuff, the "combined" position info is now prefixed with $GN.

Example NMEA coming from an unlocked F9P:

GNGLL,,,,,,V,N*7A
GNRMC,,V,,,,,,,,,,N,V*37
GNVTG,,,,,,,,,N*2E
GNGGA,,,,,,0,00,99.99,,,,,,*56
GNGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,1*33
GNGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,2*30
GNGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,3*31
GNGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,4*36
GNGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99,5*37
GPGSV,1,1,00,0*65
GLGSV,1,1,00,0*79
GAGSV,1,1,00,0*74
GBGSV,1,1,00,0*77
GQGSV,1,1,00,0*64

The version that is presently in F-droid seemed to be unable to handle this.

I'm ready to test as soon as you have something available.

Thank you!

[freshollie]

Will look into this if I get a chance, but it should be a relatively easy fix. Thanks for the details :)