On Tue, Aug 13, 2019 at 3:09 PM Gary E. Miller <
address@hidden> wrote:
Yo pisymbol!
On Tue, 13 Aug 2019 15:03:42 -0400
"pisymbol ." <address@hidden> wrote:
> > The samples are buffering because you are not reading them. You
> > need to keep up with the incoming messages.
> >
>
> Yes, I see that and now that is what I'm doing. I wrote a poller
> process that is just reading samples continuously (no sleep)
> and emits a sample into shared memory for other threads to pick up.
> The change is being tested as I write this to see if the "lag" issue
> disappears that I saw on 3.9.
You shoud neither sleep, nor poll continuously. Use the gpsd API to
wait on data available.
And in Python this looks like?
My reader just does this:
create gpsd session (gps.gps() etc.)
for report in session:
if we should still be doing this:
store report somewhere for a thread to pick up
Is there other magic out there I'm not aware of I should be using? This seems to drain the Trimble sentences continuously. Right? And this does follow the man page guidelines AFAICT.
> > A good mix, depending on your application, may be something like:
> >
> > GPGLL - Geographic Position - Latitude longitude
> > GPRMC - Recommended Minimum Specific GNSS Sentence
> > GPVTG - Course Over Ground and Ground Speed
> > GPGGA - GPS Fix Data
> > GPGSA - GNSS DOPS and Active Satellites
> > GPGSV - GNSS Satellites in View
> > GPZDA - Time & Date
> >
> > Without knowing your Trimble model, and application, it is hard to
> > say what your optimal may be.
> Are you saying I have to enable more strings for gpsd to give me a
> fix?
No. Your question was how to know you had an RTK fix. But you should
want more.
If I had a nickel...
> Basically, what I am asking is how can I get access to the GGA quality
> indicator number from the python client API?
> https://www.trimble.com/OEM_ReceiverHelp/V4.44/en/NMEA-0183messages_GGA.html
>
> Field 6.
That is remporting in the TPV JSON. RTFM: "man gpsd_json".
Will do. Again, is there any doc that talks about the Python API and how to get access to the JSON directly?
But GPGGA can only report up to 12 sats in use. You don't want to be
using an old GNSS receiver that uses so few sats...
The RTK thing on Trimble is proprietary, i.e. if you have RTK fix (4) they tell me that's that?
-aps