RE: Help needed with USB GPS device

[Gavin Davenport]

>>Replies to the list please.  Private email is for paying clients.
Apologies, hadn't spotted that was happening.

>>gpsdebuginfo is part of gpsd, so you already had it. But
>>the linked one is the latest one.
gpsdebuginfo is not in the fedora gpsd (rpm) package I have.

>>>>># Magic Hat enabled.
>>Are you on a Raspberry PI?  If not, this should be off.
No, a mini-itx PC and fedora 38. I guess Redhat are building with that enabled.

>>> 106673 ?        S<sl 125:49 /usr/sbin/gpsd -n /dev/ttyUSB0 /dev/pps0
The devices it tries to use are in /etc/sysconfig/gpsd. I have removed 
/dev/pps0 and we now have:
5 S nobody    739233       1  6  70 -10 -  4071 do_sel 10:54 ?        00:00:02 
/usr/sbin/gpsd -n /dev/ttyUSB0

>>And there is the answer to your GPS type.  It is s SiRF-III.  A tad
>>old, not so good indoors.  My condolences.  SiRF was bought out, and
>>disappearing from the market.
The label on the device itself says it's a BU-353 (It is 10+ years old and it 
was supplying GPS positions to a car PC for years)
Slightly different discussion then - what's an affordable alternative ?
Should I be avoiding all USB GPS devices ?

>>> NTP0 1709284857.228735488 1709284856.591468173 1709284856.570000000 0  -1
>>Not good enough to be a good NTP server.
I read the ntpshmon man page but I couldn't work out whether the source was 
good enough to be an NTP source.
Which column tells me that, the -1 ?
I was working on the assumption that this GPS device was good enough to be an 
NTP source, I didn't realise there was a sliding scale of device 
quality/capabilities.
Since cgps can see lots of satellites and appears to be locked, I thought that 
was good enough.

>>> Bus 001 Device 010: ID 067b:2303 Prolific Technology, Inc. PL2303
>>> Serial Port / Mobile Phone Data Cable
>>Not a real USB GPS, using a Serial/USB chip.  That can be a pain.
Yeah I spotted it wasn't announcing as a GPS explicitly.

>>> + cat /etc/sysconfig/gpsd
>>> # Options for gpsd, including serial devices
>>> OPTIONS=""
>>> # Set to 'true' to add USB devices automatically via udev
>>> USBAUTO="false"
>>> DEVICES="/dev/ttyUSB0 /dev/pps0"
>>                        ^^^^^^^^^^  Wrong, remove it.
I don't quite follow this. I remove /dev/ttyUSB0 ? Don't I also need to remove 
/dev/pps0 as the device doesn't produce PPS ?
What options does this leave me with ?

>>> I didn't know USB GPS devices tended not to have PPS.
>>And now you do.
What's the alternative ? searching the web for GPS devices gives me lots of 
handhelds, lots of USB ones but I don't know how to find which ones 
offer/support PPS.
Maybe this ?
https://gpsd.io/hardware.html


>> If no PPS is good, then you just need to figure out if gpsd is talking to
>>chronyd.  Another email from another list user had things to check on that
>>part.
I'm confused by this. Conceptually I think chrony is querying gpsd data. Do I 
need to inform gpsd about chronyd somehow ?

Many thanks
Gavin