U-Blox F9P RTK

[rhowitt]

Gary,

I have done further testing of GPSD and the F9P on the RaspberryPi

After starting GPSD with this string from the command line:
            gpsd -n /dev/ttyAMA0
ntrip://rhowitt:rhowitt@64.201.232.84:2101/UPFN -N -D 8
The F9P was not reporting RTK .

I  then interrogated CFG-UART1INPROT-RTCM3X   with  ( after reading the
documentation, this seemed like the place to start and luckily it was the
right guess.)
           ubxtool -g CFG-UART1INPROT-RTCM3X  localhost:2947:/dev/ttyAMA0

the value was:    0

Then using this command, which set the register to 1 :
           ubxtool -z CFG-UART1INPROT-RTCM3X,1 localhost:2947:/dev/ttyAMA0

The GPS started to  report that it had RTK Quality

I then set the register CFG-UART1INPROT-RTCM3X, back to 0 , and the GPS no
longer had RTK Quality.


It appears that when GPSD starts and goes through it's initialization
process, which includes several queries to the F9P, the
CFG-UART1INPROT-RTCM3X   register is getting set to 0 (zero), which turns
off RTK.

I'm guessing that GPSD is somehow, directly or some of the queries, which
are really meant for other types of gps , are being interpreted by the F9P,
setting the CFG-UART1INPROT-RTCM3X   to Zero.  I know this IS occurring
because if, while GPSD is running, I turn the power off to the GPS and then
turn the GPS back on,  the CFG-UART1INPROT-RTCM3X   register has a value of
1 ,  where just before the power was turned off the value was 0.

I tried the -b command for GPSD. The RTCM3 messages were not  passed to the
F9P. I know they were not being sent because I monitored the data lines with
the data analyzer.


So for now, in order to get the F9P into the mode where it can report RTK
quality , I will run the ubxtool -z CFG-UART1INPROT-RTCM3X,1
localhost:2947:/dev/ttyAMA0, after starting GPSD.


Regards
Rick Howitt



 



 



-----Original Message-----
From: gpsd-users <gpsd-users-bounces+rhowitt=address@hidden> On Behalf
Of Gary E. Miller
Sent: Tuesday, April 14, 2020 5:52 PM
To: address@hidden
Subject: Re: ubxtool

Yo address@hidden!

On Tue, 14 Apr 2020 16:19:51 -0400
<address@hidden> wrote:

> >>Back up a few.  So you are running StrSrv into the receiver serial 
> >>port,
> but gps is connecting to the USB port?
> 
> Since I could not put the Logic Analyzer on the USB connection I 
> switched to using the Serial Port.  On Windows and RaspberryPi a 
> serial port is being used not USB.

Sorry, my mind reading failed to follow your changes.

So, your setup is now to always send the RTCM3 data into the same port on
the receiver?  Directly on windows, and through gpsd on linux?

Correct?  Anything else change?  Or unclear?

> >>I noted before that the defaults for the u-blox serial port and USB 
> >>port
> are not the same.  I asked before for you to send us the u-blox config 
> for those ports.
> 
> Which configuration parameter do you want? 

Dunno.  The one that tells us the problem?

Maybe:
    UBX-CFG-CFG
    UBX-CFG-DGNSS
    UBX-CFG-GNSS
    UBX-CFG-INF
    UBX-CFG-NAV5
    UBX-CFG-PMS
    UBX-CFG-PRT

ubxtool needs an option to quickly dump all the config it can find.

Less important now that we know you are using the same serial port in both
case.  I assume the only difference today, is wether strsrv or gpsd is
sendgin RTCM3 to the receiver?

Have you tried the "-b" option yet?

RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
        address@hidden  Tel:+1 541 382 8588

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    "If you can't measure it, you can't improve it." - Lord Kelvin