On 10/5/13 3:44 AM, Magnus Danielson wrote:
And I want to do it quickly on a slow processor.
... and a simple high-pass filter won't do it for you?
I suppose so..I'll have to fool with that.
A high pass filter would definitely take out the DC and linear terms,
but I'm not so sure about the
On 10/5/13 8:30 AM, Magnus Danielson wrote:
Hi Jim,
On 10/05/2013 04:52 PM, Jim Lux wrote:
On 10/5/13 3:44 AM, Magnus Danielson wrote:
And I want to do it quickly on a slow processor.
... and a simple high-pass filter won't do it for you?
I suppose so..I'll have to fool with that.
A high
On 10/5/13 8:47 AM, Tim Shoppa wrote:
How slow of a processor are you working with? A modern PC using a general
purpose graphing and fitting tool (e.g. gnuplot) will fit tens of thousands
of points in a fraction of a second.
http://people.duke.edu/~hpgavin/gnuplot.html
If you want to do this in
On 10/5/13 9:10 AM, Joseph Gwinn wrote:
Re: time-nuts Digest, Vol 111, Issue 21
On Sat, 05 Oct 2013 11:54:08 -0400, time-nuts-requ...@febo.com wrote:
Message: 6
Date: Sat, 05 Oct 2013 08:53:52 -0700
From: Jim Lux jim...@earthlink.net
To: time-nuts@febo.com
Subject: Re: [time-nuts] exponential
Here's some sample raw data for those interested in what I'm working
with. Thanks a bunch for all the suggestions.
The overall goal is to take this data, remove the DC bias, linear trend,
and exponential transient baseline; then cleverly excise (or exclude
from processing) areas with obvious
On 10/6/13 9:59 PM, Hal Murray wrote:
The recent discussion of solar flares screwing up GPS timing was interesting.
I just watched Todd Humphreys TED talk again. He's focused on location, but
does mention time in terms of stock exchanges.
Todd Humphreys: How to fool a GPS
On 10/7/13 6:03 AM, Tim Shoppa wrote:
Proposing a random fitting with various curves without an underlying
physical (e.g. Eureqa) model seems... odd. That's more voodoo
engineering/science than anything real. It doesn't surprise me that
computer scientists would propose that as an approach to
On 10/7/13 7:46 AM, Collins, Graham wrote:
Indeed, the inexpensive DVB-T dongles are showing up in many places
including as David noted, decoding GPS.
The AMSAT Fun Cube Dongle is a very capable and interesting device.
Interestingly it uses the same Elonics E4000 front end chip that many
of
On 10/7/13 8:01 AM, David J Taylor wrote:
From: Collins, Graham
[]
I wonder if the Fun Cube Dongle will be likewise changed (perhaps it
already has).
Cheers, Graham ve3gtc
=
Yes, Graham, it already has been updated:
On 10/7/13 2:44 PM, Magnus Danielson wrote:
Which reminds me, there is a nifty tool called fityk that I tend to use
just to view graphs, but has a rather nice set of routines to do various
fits to various curves.
gnuplot's not bad, either..
you define a function f(x) and the free parameters,
On 10/7/13 10:44 AM, David J Taylor wrote:
From: Jim Lux
Yes, Graham, it already has been updated:
http://www.funcubedongle.com/?page_id=1073
Adds more filtering and HF coverage, but also has a dead zone between
~240 and 420 MHz.
So much for receiving signals from Transit at 400 MHz
On 10/7/13 8:31 AM, Chris Albertson wrote:
OK so let's say you have a receiver and detect a certain about of power at
the right frequency. How do you determine which of three cases you have
(1) an actual GPS signal from a satellite. (2) a spoofer (who tries hard to
look like #1) or (3) a
On 10/7/13 4:51 PM, David I. Emery wrote:
On Sun, Oct 06, 2013 at 09:59:50PM -0700, Hal Murray wrote:
Suppose I lived near a major highway. Could I build a receiver that would
count jammers driving by? Could I track them (at least somewhat) with a
directional antenna on a rotator?
On 10/7/13 6:49 PM, John C. Westmoreland, P.E. wrote:
Bob,
I think what you have pointed out is interesting - I have even given it
more than a passing thought on how to design what is on the CellBusted site.
I am working on a design of my own on how to detect low-power RF signals
using a
On 10/7/13 9:30 PM, Bill Hawkins wrote:
In general, we expect a jammer to be involved in criminal activity.
What about a wilderness guide whose reputation is built on finding
the best spots to view Nature's wonders. Should he or she be happy
to let people in the guided group save the
On 10/8/13 4:17 AM, Bob Camp wrote:
Hi
But there's obviously something wrong with the 400 KM number.
1) If +10 dbm is good enough to burry a useful signal at that distance, it
should be good enough to communicate at that distance. That's pretty impressive
QRP without high gain / directional
On 10/16/13 8:26 PM, quartz55 wrote:
I've been searching for the small copper hardline I can use for the feed on the
gps volute (egg beater) antenna. Can anyone steer me where to get a foot or so
of the small 50 ohm line so I can make a few antennas? I've been searching
mouser to no avail.
On 10/17/13 4:46 PM, Steve Byan wrote:
On Oct 17, 2013, at 3:38 PM, Richard Karlquist rich...@karlquist.com wrote:
If you are below 80 MHz, Linear Technologies makes a thermal power meter
on a chip.
Alas, the LT1088 is no longer made.
http://www.linear.com/product/LT1088
Rochester
On 10/29/13 6:31 PM, Bob Camp wrote:
Hi
That’s always one of those “we can only tell you if you work for the US
government” sort of things. If anybody knows it’s one of those “you better not
tell” things.
or more likely..
If you put actual mfr and model in, then you have to go through a
On 10/29/13 7:06 PM, John C. Westmoreland, P.E. wrote:
Bob,
Yes - well, it is a little dated - so I would think the chance for a
competitive edge would have expired. Maybe not for models C and D but I
would certainly think so for Models A B.
There must be some sort of technical statute of
On 10/30/13 3:46 PM, Magnus Danielson wrote:
Hi,
They have learned the hard way that they can't do that easily. They can,
if they add the necessary mentioning of vendor X and their product Y
does in no way means an endorsement. I've seen presentations starting
with a non-endorsement statement
On 10/31/13 4:02 AM, Bob Camp wrote:
Hi
The control voltage on the 12 V OCXO is likely 0-10V or 0-5V. The
tune on the 3.3V part isn’t going to be above 3.3V and it may be
0-2.5V. The 3.3V part is going to be at least 8X more sensitive to
grounding issues.
I've got a BUNCH of VCOs that are
On 11/2/13 7:40 PM, Magnus Danielson wrote:
On 11/03/2013 02:45 AM, Bob Camp wrote:
Hi
I believe that you are talking to two very different groups, one who actually
design the crystals and the other who use the products that are designed. One
is talking about what they can buy, the other is
On 11/3/13 4:27 AM, Magnus Danielson wrote:
Hi Jim,
Ground-based GPS-like transmitters could be a nice option to consider.
Well, that's basically what we do today. We transmit a very stable
carrier with some tones or a PN sequence modulated onto it. The
spacecraft recovers it, generates a
On 11/4/13 6:51 PM, saidj...@aol.com wrote:
Hi John,
well, I think he must have meant a new car back in 1971 :) That would be
about right. It's not quite THAT expensive.
Ford Pinto sold for $1999 in the early 70s. Not that I want to compare
a CSAC to a Pinto, but...
Symmetricom seized
On 11/17/13 2:38 PM, Don Lewis wrote:
I didn't think Stonehenge told 'time' ala a sundial.
Its' purpose was to herald the seasons' change, etc, I thought.
Ah, so you think this is more of a calendar-nut item than a time-nut..
What about a iPhone App? Orient the device using the built in
On 11/19/13 9:13 AM, Dr. David Kirkby wrote:
If it is made up from PIN diodes, I wonder what the logic of Agilent
letting you read the number of times they have switched?
Common firmware between units?
___
time-nuts mailing list --
On 11/21/13 3:28 PM, Chris Albertson wrote:
On Thu, Nov 21, 2013 at 11:11 AM, Don Latham d...@montana.com wrote:
Lord no, John. No red wagon is needed. Use a pole and the equation of
time, and a good watch or clock. At local noon, a shadow will be a n-s
line.
How accurate do you need to be?
On 11/21/13 11:32 PM, Robert Atkinson wrote:
I'd also go for a compass if you want magnetic north, but then I have a good one, a
medium landing compass. Mine dates from WWII but they are still made
http://www.sirs.co.uk/ground/landing_compasses/patt2/landing_resource
These are used to align
On 11/24/13 4:23 AM, Didier Juges wrote:
The Thunderbolt uses single precision floating point and digital filtering for
temperature so yes, you are going to see values like this. This is not unusual
(precision clearly out of step with accuracy), like the HP network analyzers
returning gain in
On 11/26/13 8:51 AM, Attila Kinali wrote:
On Tue, 26 Nov 2013 11:37:10 -0500
quartz55 quart...@hughes.net wrote:
Does anyone know what is inside the commercial units, like the PCTEL
GPS-TMG-HR-26N I have?
Three types of GPS antennas are common:
* ceramic carrier patch antennas
* cross
On 11/27/13 8:08 AM, Chuck Harris wrote:
Here is some Electrical Engineer pr0n of the Trimble TBolt standard
antenna.
-Chuck Harris
Apparently spelling out the P word gets your message rejected.
Is that a L1 only antenna?
What's interesting is that this is NOT a crossed dipole, at least
On 11/27/13 11:21 PM, Attila Kinali wrote:
On Wed, 27 Nov 2013 04:02:53 -0800
Jim Lux jim...@earthlink.net wrote:
[Crossed dipole antennas]
I don't know how they do the phase quadrature.. do they
make one dipole a bit longer and the other a bit shorter?
Yes. Same principle as with patch
On 11/28/13 1:35 AM, Wolfgang Wallner wrote:
Hello Time-Nuts community,
I'm interested in the simulation of oscillator noise (especially in discrete
event simulators).
PS: When I use the word oscillator I mean the cheap quartz oscillators as found
in typical consumer electronic stuff.
PPS:
On 11/28/13 6:27 AM, Chuck Harris wrote:
As far as I know it is L1 only. It is a Bullet II HE, P/N 25045-10,
the standard antenna specified in the Thunderbolt manual.
If you look closely, you will notice that what appears to be a
single soldered joint at the middle, is really two solder
On 11/29/13 5:56 AM, Azelio Boriani wrote:
Unfortunately that was a contribution from Magnus in 2010
(see www.febo.com/pipermail/time-nuts/2010-April/046932.html )
that I have simply reported without verifying the link and found that
link unusable after sending the message. My best guess is
On 11/29/13 8:50 AM, Magnus Danielson wrote:
On 11/29/2013 04:11 PM, Jim Lux wrote:
On 11/29/13 5:56 AM, Azelio Boriani wrote:
Unfortunately that was a contribution from Magnus in 2010
(see www.febo.com/pipermail/time-nuts/2010-April/046932.html )
that I have simply reported without
On 11/30/13 2:15 PM, Tom Van Baak wrote:
Jim,
Could you just replay real data instead of trying to generate
simulated data? There's plenty of storage with Arduino or SD card
shields.
Attached is frequency and ADEV of my heart beat for 10 hours. You
could do the same. In this case the flicker
On 11/30/13 2:15 PM, Tom Van Baak wrote:
Jim,
Could you just replay real data instead of trying to generate simulated data?
There's plenty of storage with Arduino or SD card shields.
Attached is frequency and ADEV of my heart beat for 10 hours. You could do the
same. In this case the flicker
On 11/30/13 5:33 PM, Hal Murray wrote:
t...@leapsecond.com said:
Attached is frequency and ADEV of my heart beat for 10 hours.
Neat. What did you use to collect the raw data?
There's a few Arduino/Sparkfun/Adafruit widgets out there that receive
the signals from off the shelf Polar
On 12/9/13 6:12 AM, Daniel Mendes wrote:
It´s still used in the oil industry as the standard for temp and
pressure monitoring...
Probably because they're an inherently rugged sensor
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe,
On 12/10/13 5:57 PM, Don Latham wrote:
I always thought invar was the magic metal. Quartz rod? You can get
those
at some reasonable cost?
12 mm dia fused qtz, about $10 per ft, so under $40 to get going,
assuming 4 or 5 to learn how to do it right. It does break...
12.7 mm dia Invar 1 m long
On 12/12/13 6:31 AM, Brian Lloyd wrote:
I am currently using both Trimble Thunderbolt and LPRO-101 Rb references.
What I really would like to have is a rack-mountable unit that is a
GPS-disciplined Rb reference and a built-in NTP server. (Yes, this is for
my home. We are time-nuts, aren't we?) I
On 12/12/13 4:28 PM, Tom Harris wrote:
The eccentric English physicist Boys made quartz fibres by attaching one
end to a crossbow bolt, heating the middle and then firing the bolt, at
what I have been unable to determine. He used this to measure the
gravitational constant by suspending iron
On 12/26/13 8:07 AM, ct1dmk wrote:
Hello,
I'm willing to generate a pulse (of some few hundred volts)
by discharging a capacitor into a pulse transformer
I'm solely interested is the active edge (call it either rise or fall
depending on the
wiring of the output of the transformer).
ns
On 12/30/13 7:56 AM, Anders Wallin wrote:
I've tested the AD9912 evaluation board:
http://www.anderswallin.net/wp-content/uploads/2013/12/dds_test_2013-12-30.png
I want to use it with a 10MHz external input clock, but it looks like the
on-board PLL that generates a 1200MHz sample clock from my
On 12/31/13 8:07 AM, Anders Wallin wrote:
Could the remaining -60 dBc spurs at +/- 50 kHz be due to my 10MHz clock
source, an Agilent 33120A?
Yes the spurs could be from your source. that's a function generator/ARB
and spectral purity isn't one of the big design criteria for that kind
of
On 1/1/14 10:28 PM, David J Taylor wrote:
From: Hal Murray
Are there any events similar to New Years where some specific countdown
time
is shown on TV?
Rocket launches, although typically not on live TV any more. More likely
streamed (at least that's how I watch them). In the post launch
On 1/2/14 11:56 AM, Chris Albertson wrote:
When they broadcast live TV like from a sports vent I wonder if the time
code generated by the camera is preserved? But then even if it were the
time might have been set manually to match the display on the camera
operator's cell phone.
Depends on
On 1/2/14 11:33 AM, Bill Hawkins wrote:
IIRC, the reason why NTSC has an almost 30 fps rate is that early
vacuum tube TV sets could develop heater-cathode leakage that
would put a black hum bar in the picture. Almost 30 allows the
bar to move through the picture in a 60 Hz power distribution
On 1/2/14 2:33 PM, Chuck Forsberg WA7KGX wrote:
Why didn't they make the color burst an exact multiple of 60 Hz?
Round numbers and such
http://en.wikipedia.org/wiki/Colorburst
has a nice description..
The whole thing of backwards compatibility and squeezing the maximum
amount of
On 1/6/14 6:05 AM, Magnus Danielson wrote:
MEMS might be good for certain tasks, but for closer in noise I've only
seen some progress recently, but not measured it myself. Close-in noise
seems to have been pretty bad for all MEMS so far.
I think that's probably related to the physically
On 1/6/14 8:36 PM, Magnus Danielson wrote:
Bob,
It works the other way around. The standard Bell handset (103A I believe
the designation was) has the 300-3400 Hz response, and with not so fancy
analogue filtering, you can handle 4 kHz and thus 8 kHz sampling rate.
The ITU-T G.711 A-law (where
On 1/6/14 9:44 PM, Magnus Danielson wrote:
Jim,
On 07/01/14 05:43, Jim Lux wrote:
On 1/6/14 8:36 PM, Magnus Danielson wrote:
Bob,
It works the other way around. The standard Bell handset (103A I believe
the designation was) has the 300-3400 Hz response, and with not so fancy
analogue
On 1/8/14 9:06 PM, David I. Emery wrote:
On Wed, Jan 08, 2014 at 08:09:04PM -0500, Charles Steinmetz wrote:
Nathaniel wrote:
Following from that, suppose a jammer parks nearby and doesn't leave
in a timely fashion. How long does it take for the FCC to swoop in
(do they swoop? in my mind they
http://arstechnica.com/security/2014/01/dos-attacks-that-took-down-big-game-sites-abused-webs-time-synch-protocol/
Interesting.. throw requests at an NTP server that look as if they come
from the target, prompting large responses to the victim, presumably to
overload it.
The article talks
On 1/10/14 1:06 PM, Paul wrote:
On Fri, Jan 10, 2014 at 2:52 PM, Chris Albertson
albertson.ch...@gmail.comwrote:
It's not a big deal. Even if one pool NTP server is down
On Fri, Jan 10, 2014 at 4:32 AM, Jim Lux jim...@earthlink.net wrote:
The article talks about how the victim site can
On 1/17/14 8:43 AM, Michael Perrett wrote:
Magnus, I believe that he is referencing the the new L2 C/A code, which is
not protected. Reference
http://www.gps.gov/systems/gps/modernization/civilsignals/
Is the L2c officially on yet? and how many S/V are radiating it? I know
there was some
On 1/17/14 11:35 AM, Magnus Danielson wrote:
On 2014-01-16 20:29, Hal Murray wrote:
anders.e.e.wal...@gmail.com said:
The real benefit of dual-frequency is you can do post-processing with
PPP.
Javad has some modules but they start at 3 kUSD - if anyone knows of
hobby
level priced L1/L2
On 1/18/14 2:25 PM, P Nielsen wrote:
I am looking for a physical clock (not software) that will indicate local
solar time. IOW when the sun is at its highest point, the clock would
reliably read 12:00 throughout the year.
So it needs to take into account the equation of time?
there's
On 1/18/14 2:25 PM, P Nielsen wrote:
I am looking for a physical clock (not software) that will indicate local
solar time. IOW when the sun is at its highest point, the clock would
reliably read 12:00 throughout the year.
Is there a commercial product or kit available for this?
On 1/18/14 4:22 PM, Tom Van Baak (lab) wrote:
Add GPS if you want the clock to self-adjust when moved east or west (noon
moves a couple of milliseconds per meter). This feature would be especially
cool if the clock were used in a vehicle.
Ooohh... an automatic self adjusting sundial for
On 1/18/14 2:25 PM, P Nielsen wrote:
I am looking for a physical clock (not software) that will indicate local
solar time. IOW when the sun is at its highest point, the clock would
reliably read 12:00 throughout the year.
Once you buy into a microprocessor, it's pretty easy to make all
Just in case you want to build a clock with an Arduino..
http://jorisvr.nl/arduino_frequency.html
ADEV measurements, etc.
take home message.. absolute accuracy is a few kHz out of 16 MHz...
probably a 100 ppm crystal.
On some Arduinos (or Teensy3's which is what I use) there's a provision
On 1/18/14 5:11 PM, Bill Dailey wrote:
http://www.precisionsundials.com
The sawyer looks like it fits the bill.
$8,000
Actually, only $2,100.. that fancy helical thing Renaissance was the 8
kilobuck one..
The Sawyer thing has a lot of nice design features. Very clever how
they do the
On 1/18/14 5:23 PM, Mark Sims wrote:
Lady Heather can display time in LMST/LAST/GMST/GAST
I made a version that has an option to just show the date/time in full screen
mode for Jim Lux/JPL but never heard back from him.
I have passed it on to the person
I'm working on it now. Got the arduino UNO, need to go get a cheap cook
tomorrow
On Jan 18, 2014, at 18:01, P Nielsen pniel...@tpg.com.au wrote:
Thank you for the suggestions so far.
When I said no software, I meant not something like this:
On 1/19/14 2:00 AM, P Nielsen wrote:
To Jim Lux. After you get it working, would you consider putting the details
online, or selling as a kit?
Half coded.
I'll publish all the details..
It's pretty easy.. a Arduino, a clock, a wall wart to power it. I
haven't tried it yet (no clock to test
On 1/19/14 1:49 AM, Chris Albertson wrote:
On Sat, Jan 18, 2014 at 11:14 PM, David J Taylor
david-tay...@blueyonder.co.uk wrote:
Are you perhaps thinking of sidereal time, Chris?
Either way, the difference is within the limits of the basic tin wind-up
alarm clock. A quality wrist watch
On 1/19/14 9:17 AM, Chuck Harris wrote:
The usual quartz clock that runs off of a AA cell is a little
trickier to drive than you might think. You need to feed
its stepper motor coil with an alternating +1.5V and -1.5V pulse.
The pulse follows the rising or trailing edge of a 1/2 Hz square
wave.
On 1/19/14 9:40 AM, David J Taylor wrote:
From: Jim Lux
Right now, the EOT is changing almost 30 seconds/day, which implies that
the clock could be some seconds off during part of the day (although
true at noon).
[]
30 seconds/day?
http://www.sundials.co.uk/pix/c/eot3.gif
from:
http
); // turn off pulse
pinMode(D1,INPUT);
}
That way you're not drawing power most of the time..
-Chuck Harris
Jim Lux wrote:
On 1/19/14 9:17 AM, Chuck Harris wrote:
The usual quartz clock that runs off of a AA cell is a little
trickier to drive than you might think. You
On 1/19/14 10:47 AM, Don Latham wrote:
Jim: I used a simple f/f, q and ~q and 180 ohm resistors. Could easily
be done with two ard outputs. needs 1/2 sec cycle. i just disconnected
the coils from the epoxied blob with the clock electronics. You can also
drive it backwards if it amuses. . .
Don
On 1/19/14 11:21 AM, Tom Van Baak wrote:
Yeah.. that *is* the challenge.
Use two outputs and make a sort of H bridge
Jim,
No problem.
1) equation of time:
See www.leapsecond.com/tools/eot1.c, source code that generates the equation of time and
its derivative. Sample output attached. You
So, Tom's EOT routine takes less than a millisecond to execute (in
double precision) on the Arduino..
So what I can probably do is call it every minute or hour to update the
rate for the next minute/hour.
Now I just have to figure out how to conveniently set the current
date/time (for now,
On 1/19/14 11:24 AM, Bob Camp wrote:
Hi
I’d put the table(s) in flash. You aren’t going to change it often enough to
matter in terms of re-flash cycles. They would all be pre-calculated for that
clock at that location, starting from today. In my approach this would be a
very application
On 1/19/14 12:20 PM, David J Taylor wrote:
From: Jim Lux
http://www.wsanford.com/~wsanford/exo/sundials/equation_of_time.html
5 Jan 5.2 minutes
6 Jan 5.7 minutes
30 seconds in a day..
The total variation over the year is +/- 15 minutes, but the derivative
is a lot bigger at some times
It turns out there's a handy Arduino library for time. And it will
ingest GPS or NTP, etc., as well as run off the internal clock.
One strategy, then, is:
Set the clock in the Arduino
then, periodically (once a minute or hour)
look up the date and time
calculate rate
On 1/19/14 1:51 PM, Tom Van Baak wrote:
So, periodically, one would need to reset both the analog clock AND the
Arduino clock to bring them back to proper alignment.
I suppose that periodically, one could compare number of ticks sent
with UTC + EOT offset and try to compensate (by dropping
On 1/19/14 3:58 PM, Chris Albertson wrote:
It is. Both double and float are 32-bits. Arduino uses the GCC AVR
compiler.
If you care a lot about precision you use integer math and do all your
calculations in integer units of milli or microseconds. If you try to keep
time in floats you are
.
---
#include Time.h
// Solar clock to drive mechanical mechanism
// Jim Lux, 19 Jan 2014
#include math.h
#define TIME_MSG_LEN 11 // time sync to PC is HEADER followed by Unix
time_t as ten ASCII digits
#define TIME_HEADER 'T' // Header tag for serial time sync message
#define TIME_REQUEST
On 1/19/14 6:41 PM, Lizeth Norman wrote:
Hi all,
Funny how this topic of the arduino time library comes around. Have been
following your conversations regarding the precise nature of arduino time
(gps time aware)
Is it possible to write (assuming the poor little creature would do it) a
piece of
On 1/19/14 8:00 PM, P Nielsen wrote:
It's not clear if the OP wants true local time or the time at the center of
his time zone.
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
My original idea was to have 12 noon equate to the sun's
On 1/19/14 10:31 PM, Chris Albertson wrote:
On Sun, Jan 19, 2014 at 6:41 PM, Lizeth Norman normanliz...@gmail.comwrote:
Is it possible to write (assuming the poor little creature would do it) a
piece of code, that given your lat/long, the time and a two line element
set for an orbiting
to compensate..
Or, provide a finer resolution for the timer libraries.
I suspect someone has already done this, so I'll do some googling.
#include TimerOne.h
#include Time.h
// Solar clock to drive mechanical mechanism
// Jim Lux, 19 Jan 2014
// assumes a mechanical clock is connected
much the same for it as well. The math gets a bit more
complicated, but the drop / add result nets out to the same thing.
Yes, that's something I need to add: a overall rate adjust to
calibrate the crystal.
Bob
On Jan 20, 2014, at 11:19 AM, Jim Lux jim...@earthlink.net wrote:
here's
On 1/20/14 9:20 AM, Jim Lux wrote:
Interestingly, it occurred to me that one could just add a sufficiently
large deviation random number to the period each time to dither it.
The rate changes once per hour (per tvb's EOT routine), so there's
3600 ticks at a given rate. If I were to vary
On 1/20/14 9:48 AM, Bob Camp wrote:
Hi
There are *lots* of ways to do any sort of code. I can’t think of any practical
problem that has a single unique “best” way to do it. All I’m trying to say is
that there is a way to get the job done (to much better accuracy than you need)
with what you
On 1/19/14 1:51 PM, Tom Van Baak wrote:
Use 24h clocks for
best results. They can be had from www.clockkit.com, an excellent
source of DIY quartz clock parts.
I couldn't find 24hr movements on the clockkit.com site.. where are they?
___
On 1/20/14 10:06 AM, Jim Lux wrote:
On 1/19/14 1:51 PM, Tom Van Baak wrote:
Use 24h clocks for
best results. They can be had from www.clockkit.com, an excellent
source of DIY quartz clock parts.
I couldn't find 24hr movements on the clockkit.com site.. where are they?
http
So here's my next idea..
Set up a 24 hour movement (no minute hand) so that you have the sun
moving around the dial: at the top at solar noon, with the rate being
reasonably constant around the dial(e.g. using the solar clock
algorithms developed)
Then, have two other pointers or sectored
On 1/20/14 11:00 AM, Bob Camp wrote:
Hi
I realize this is *exactly* what the OP didn’t want to do, but ….
A PI or any of the little dedicated ARM + GPU gizmos driving a cheap junk HDMI
monitor or TV would make for a very nice display of all that data… The total
cost could still be under
On 1/20/14 3:32 PM, Rex wrote:
That listing is a bit vague about if it has a second hand. For the kind
of pulse drive that has been discussed here, it seems you would want a
definite second capability and step vs. smooth second hand drive.
I know nothing except a little web searching, but this
On 1/20/14 5:57 PM, Robert LaJeunesse wrote:
Since most of those cheapo movements are a simple single-coil motor, energized with alternating
polarity short pulses, it would seem that there is no need for a 24 hour movement. You
can just have your micro pulse it twice the normal period, but
On 1/20/14 6:15 PM, Chris Albertson wrote:
On Mon, Jan 20, 2014 at 6:54 AM, Jim Lux jim...@earthlink.net wrote:
On 1/19/14 10:31 PM, Chris Albertson wrote:
On Sun, Jan 19, 2014 at 6:41 PM, Lizeth Norman normanliz...@gmail.com
wrote:
This is why I am a fan of the Teensy3... It's
On 1/24/14 11:57 AM, Volker Esper wrote:
Nice! I didn't know that. But what a number, 300... Why such a
digital-hostile factor? Why not 256 or 512?
Volker
Am 24.01.2014 20:51, schrieb tmil...@skylinenet.net:
9.8304 MHz divided by 300 is 32,768 Hz.
Feed that to an electronic clock and you
On 2/13/14 10:09 AM, Chris Albertson wrote:
-- Forwarded message --
From: Chris Albertson albertson.ch...@gmail.com
Date: Thu, Feb 13, 2014 at 8:58 AM
Subject: Re: Atmega?
I posted this off list, but I'm reposting on the list with mnor edits. I
think there might be people
On 2/13/14 4:27 PM, Bob Camp wrote:
Hi
The number of bits and the performance of the ADC’s on the Arduino’s is pretty
underwhelming compared to the stuff on other similarly priced MCU’s. If you are
doing a design where the ADC matters, a PIC or just about anything from TI or
Freescale will
On 2/16/14 11:55 AM, Jimmy D. Burrell wrote:
I've looked at several different manufacturer GPS datasheets now
regarding the 1 PPS output in an attempt to compare apples to apples.
Some of them rate their 1 PPS output as something on the order of
PPS signals have an accuracy ranging 10ns which
On 2/19/14 10:24 AM, Brooke Clarke wrote:
Hi:
This means that the concrete piers where many Cesium clocks and GPS
reference stations are located are bobbing up and down as if they were
on a ocean, although only tens of inches.
My GPS friends comment when you start getting to sub-meter
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