Re: [gpsd-users] UBX-TIM-TP on F9T?

[Gary E. Miller]

Yo Anders!

On Thu, 3 Oct 2019 16:53:27 +0300
Anders Wallin <address@hidden> wrote:
 
> > I want to log the UBX-TIM-TP message (in particular the quantization
> > error of the timepulse), using the python gps module if possible.  

I have been working on this today, but I'm not ready to push today.

My test gpsd now puts the TIM-TP qErr in the PPS JSON message.  That
gets sent at the right time, and is with its PPS friends.

The expanded message looks like this:

{"class":"PPS","device":"/dev/ttyS0","real_sec":1570153135,"real_nsec":0,"clock_sec":1570153135,"clock_nsec":3350,"precision":-20,"qErr":-1681}

It should work fine with Python.  You just need to build from git head.

I'll also use qErr to adjust the PPS as sent top NTP.  The difference
will likely be buried in clock jitter.

Here is the qErr from a NEO-M8N:

       -4
    10027
     -999
     8029
    -3939
     4760
    -7371
     2115
    -8598
     1803
    -8727
    -2060
     7515
    -2475
     6534

Eyeballing I get +/- 10ns.

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

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