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Re: [gpsd-users] Python GPSD interface and symmetricon 2750
From: |
Gary E. Miller |
Subject: |
Re: [gpsd-users] Python GPSD interface and symmetricon 2750 |
Date: |
Sat, 14 Apr 2018 09:55:52 -0700 |
Yo Ryan!
On Sat, 14 Apr 2018 14:20:02 +0000
Ryan Tennill <address@hidden> wrote:
> For some reason the python interface doesn't seem to be picking up the
> number of satellites or the fix status.
Which Python client? gpsd does not get the number of sats from the
fix status, it gets that from GPGSV.
> I am parsing the responses
> myself to work around this behavior
So you see good JSON from gpsd? Just no "SKY" JSON? No GPGSV, then
no "SKY".
> but I would like to use more
> tried and tested machinery in gpsd if it's available.
It should be there, or it will get fixed.
> I assume I just
> don't have it configured correctly.
gpsd intentionally has few knobs. It is meant to "just work". Or
do you mean your client?
> The GPS is configured to send GGA and RMC messages over the serial
> interface which seems to be working just fine. I get good data when
> watching gpspipe and gpsmon does show the proper fix status and
> satellite count.
A good sign. Remember that when gpsd starts it also does some
reconfiguring. Unless you use the gpsd -b option to stop that. But
-b is not totally effective.
> Here's what the client looks like after receiving some GGA and RMC
> messages:
>
> Time: 2018-04-13T14:21:15.000Z (2018-04-13T14:21:15.000Z)
> Lat/Lon: 40.116415 -88.311605
> Altitude: 227.000000
> Speed: 0.000000
> Track: 0.000000
> Status: STATUS_NO_FIX
> Mode: MODE_3D
> Quality: 0 p=0.00 h=0.00 v=0.00 t=0.00 g=0.00
> Y: 0 satellites in view:
>
>
> Some example sentences are:
>
> '$GPRMC,142115.00,A,4006.9849,N,08818.6963,W,0.0,0.0,130418,,*21\r\n'
> '$GPGGA,142116.00,4006.9849,N,08818.6963,W,2,10,0.9,227.0,M,-33.2,M,,*51\r\n'
No sat data in there. You need GPGSV to get the sat data.
No DOP data in there. For that you need GPGSA.
> Datasheet: https://www.microsemi.com/existing-parts/parts/138158
> Setup: GPS-2750 over UART (not USB-Serial) to a Nvidia Jetson TX2
> running Ubuntu 16.04 (arm64)
> GPSD version: 3.15 (revision 3.15-2build1)
> Watch flags: WATCH_ENABLE|WATCH_JSON|WATCH_RAW
Nice little board. 15 ns PPS acccuracy is nice, but not exactly what I
would call "atomic accuracy".
RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
address@hidden Tel:+1 541 382 8588
Veritas liberabit vos. -- Quid est veritas?
"If you can’t measure it, you can’t improve it." - Lord Kelvin
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