Knowing when the PPS signal is locked to the satellite.
I am using a NEO-6M to provide a PPS signal for an experiment but I need
to know when it is locked or not.
Does anyone know if there is a way to find out from either the NMEA data
stream or via the proprietary protocol ??
At the moment I have it programmed to only provide a PPS signal when it
is locked (or nothing if not) and monitor
the PPS signal in the microprocessor, but it's not entirely satisfactory
and I need a better mechanism.
Dave
The status flag in the $GxRMC message tells you if the unit is 'locked'
The PPS appears more-or-less when that flag goes from 'V' to 'A'
Andy
www.g4jnt.com
On Wed, 22 Jun 2022 at 14:23, Dave via time-nuts time-nuts@lists.febo.com
wrote:
I am using a NEO-6M to provide a PPS signal for an experiment but I need
to know when it is locked or not.
Does anyone know if there is a way to find out from either the NMEA data
stream or via the proprietary protocol ??
At the moment I have it programmed to only provide a PPS signal when it
is locked (or nothing if not) and monitor
the PPS signal in the microprocessor, but it's not entirely satisfactory
and I need a better mechanism.
Dave
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Dave,
I would suggest using the GPSD project. The software is aware of, and
corrects, various quirks and gotchas in GPS devices.
You can use anything from polling JSON over telnet to a C API, and it will
reliably report the current mode, precision, etc. Please see the 'status'
and 'mode' messages here: https://gpsd.gitlab.io/gpsd/gpsd_json.html#_tpv
And the good news is, the authors of the software are on this list :-)
--
Sanjeev Gupta
+65 98551208 http://www.linkedin.com/in/ghane
On Wed, 22 Jun 2022 at 21:23, Dave via time-nuts time-nuts@lists.febo.com
wrote:
I am using a NEO-6M to provide a PPS signal for an experiment but I need
to know when it is locked or not.
Does anyone know if there is a way to find out from either the NMEA data
stream or via the proprietary protocol ??
At the moment I have it programmed to only provide a PPS signal when it
is locked (or nothing if not) and monitor
the PPS signal in the microprocessor, but it's not entirely satisfactory
and I need a better mechanism.
Dave
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Hi Dave,
the UBX-NAV-STATUS and UBX-TIM-TP messages should give you a good
indication.
Regards
Markus
I am using a NEO-6M to provide a PPS signal for an experiment but I
need to know when it is locked or not.
Does anyone know if there is a way to find out from either the NMEA
data stream or via the proprietary protocol ??
At the moment I have it programmed to only provide a PPS signal when
it is locked (or nothing if not) and monitor
the PPS signal in the microprocessor, but it's not entirely
satisfactory and I need a better mechanism.
Dave
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
On Mittwoch, 22. Juni 2022 14:59:29 CEST Dave via time-nuts wrote:
I am using a NEO-6M to provide a PPS signal for an experiment but I need
to know when it is locked or not.
Does anyone know if there is a way to find out from either the NMEA data
stream or via the proprietary protocol ??
You can check e.g. the UBX-NAV-PVT message, if will tell you if the receiver
has a valid UTC time and also the time uncertainty and what type of fix
generated the nav solution. Or, UBX-NAV-TIMEUTC. Or, just UBX-NAV-STATUS.
You can assume that as soon as a 3D or TIME fix is reported, the PPS is locked
to GPS, or once the time uncertainty drops below a certain threshold.
Note that this is what an M8 receiver will provide. I don't have any manual
for the M6 receivers at hand, so the actual messages might be different for a
M6 which supports a different protocol version than the M8.
At the moment I have it programmed to only provide a PPS signal when it
is locked (or nothing if not) and monitor
the PPS signal in the microprocessor, but it's not entirely satisfactory
and I need a better mechanism.
That's not a bad mechanism actually. The PPS output is practically useless
while the receiver is not locked to GPS.
Hi
Keep in mind that if you run the PPS when unlocked, the uBlox does not
“play nice” when it locks up. The PPS moves to where ever it needs to be
quite abruptly. That may or may not create issues, depending on your
application.
Bob
On Jun 22, 2022, at 4:59 AM, Dave via time-nuts time-nuts@lists.febo.com wrote:
I am using a NEO-6M to provide a PPS signal for an experiment but I need to know when it is locked or not.
Does anyone know if there is a way to find out from either the NMEA data stream or via the proprietary protocol ??
At the moment I have it programmed to only provide a PPS signal when it is locked (or nothing if not) and monitor
the PPS signal in the microprocessor, but it's not entirely satisfactory and I need a better mechanism.
Dave
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe send an email to time-nuts-leave@lists.febo.com
Thanks all for the tips I'll investigate over the next couple of days.
Dave
On 22/06/2022 15:48, Matthias Welwarsky via time-nuts wrote:
On Mittwoch, 22. Juni 2022 14:59:29 CEST Dave via time-nuts wrote:
I am using a NEO-6M to provide a PPS signal for an experiment but I need
to know when it is locked or not.Does anyone know if there is a way to find out from either the NMEA data
stream or via the proprietary protocol ??
You can check e.g. the UBX-NAV-PVT message, if will tell you if the receiver
has a valid UTC time and also the time uncertainty and what type of fix
generated the nav solution. Or, UBX-NAV-TIMEUTC. Or, just UBX-NAV-STATUS.
You can assume that as soon as a 3D or TIME fix is reported, the PPS is locked
to GPS, or once the time uncertainty drops below a certain threshold.
Note that this is what an M8 receiver will provide. I don't have any manual
for the M6 receivers at hand, so the actual messages might be different for a
M6 which supports a different protocol version than the M8.
At the moment I have it programmed to only provide a PPS signal when it
is locked (or nothing if not) and monitor
the PPS signal in the microprocessor, but it's not entirely satisfactory
and I need a better mechanism.
That's not a bad mechanism actually. The PPS output is practically useless
while the receiver is not locked to GPS.
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To unsubscribe send an email to time-nuts-leave@lists.febo.com