Bob wrote:
You can achieve very good accuracy, but at the cost of waiting
thousands of seconds between phase points; i.e. where your 1PPS
coincides with the 10 millionth OCXO pulse.
So, as your 1PPS pulse bobs back and forth, you will often encounter
an OCXO pulse up to 10ns early, or up to
: [time-nuts] GPSDO with all-digital phase/time measurement?
Bob wrote:
You can achieve very good accuracy, but at the cost of waiting thousands of
seconds between phase points; i.e. where your 1PPS coincides with the 10
millionth OCXO pulse.
So, as your 1PPS pulse bobs back and forth, you
Thanks to everyone who responded. I had this bright idea that I would turn
off mail delivery and just read the list through the pipermail interface.
It works great, until you want to reply to a message. Sorry if this breaks
the thread in two.
Language is imprecise even when carefully thought
From: Charles Steinmetz csteinm...@yandex.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Friday, February 28, 2014 12:29 PM
Subject: Re: [time-nuts] GPSDO with all-digital phase/time measurement?
Bob wrote:
You can achieve
hau...@keteu.org said:
That being said, I find myself wondering as follows: Suppose that we count
OCXO cycles (at, say, 10 MHz) using one of the MCU's timer/counter
peripherals, and periodically sample the counter value with an interrupt
triggered on the rising edge of the GPS 1pps. Assume
-nuts@febo.com
Cc: hmur...@megapathdsl.net
Sent: Thursday, February 27, 2014 1:13 AM
Subject: Re: [time-nuts] GPSDO with all-digital phase/time measurement?
b...@evoria.net said:
At least on the PIC I'm using, the CCP and timer interrupts don't seem to be
synchronous with the PIC clock. I
on your 1PPS pulse.
Bob
From: Alexander Pummer alex...@ieee.org
To: Bob Stewart b...@evoria.net; Discussion of precise time and frequency
measurement time-nuts@febo.com
Sent: Thursday, February 27, 2014 7:42 AM
Subject: Re: [time-nuts] GPSDO with all-digital phase
you get.
Anyway, those are my experiences.
Bob - AE6RV
From: Mark Haun hau...@keteu.org
To: time-nuts@febo.com
Sent: Wednesday, February 26, 2014 3:51 PM
Subject: [time-nuts] GPSDO with all-digital phase/time measurement?
Hi everyone,
I'm new to the list
Hi everyone,
I'm new to the list, and have been reading the recent threads on
Arduino-based GPSDOs and the pros/cons of 10-kHz vs 1-Hz time pulses with
interest.
As I understand it, there are a couple of reasons why one needs a
time-interval / phase measurement implemented outside the MCU:
1)
* all of this, to document it, to experiment,
and to possibly improve on it over time.
/tvb
- Original Message -
From: Mark Haun hau...@keteu.org
To: time-nuts@febo.com
Sent: Wednesday, February 26, 2014 1:51 PM
Subject: [time-nuts] GPSDO with all-digital phase/time measurement?
Hi
At this point the time measurement is quite crude, with 100-ns resolution.
But because we keep the counter running, the unknown residuals will keep
accumulating, and we should be able to average out this quantization
noise
What you are saying is With a long enough gate time you can measure
to live with whatever quantization errors you get.
Anyway, those are my experiences.
Bob - AE6RV
From: Mark Haun hau...@keteu.org
To: time-nuts@febo.com
Sent: Wednesday, February 26, 2014 3:51 PM
Subject: [time-nuts] GPSDO with all-digital phase/time measurement
could be mistaken.
Bob
From: Tom Van Baak t...@leapsecond.com
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Wednesday, February 26, 2014 11:22 PM
Subject: Re: [time-nuts] GPSDO with all-digital phase/time measurement
b...@evoria.net said:
At least on the PIC I'm using, the CCP and timer interrupts don't seem to be
synchronous with the PIC clock. I could be mistaken.
Unless you have a very strange architecture, it doesn't make sense for an
interrupt to not be synchronous with the CPU clock. You are in
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