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Hardware => Lynx Aeon => Topic started by: rimist on February 13, 2012,
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Any idea if it's possible to automatically set the Aeon to an atomic clock?
-Rimist (via Tapatalk)
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That must be the super secret use for the unused connection at the top of the PCB 8)
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Sure get the time from the Atomic clock and set the Aeon to that exact time. Simple
Rick R.
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I'm sure that in 1985 plutonium is available in every corner drugstore, but in 1955 it's a little hard to come by.
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I'm sure that in 1985 plutonium is available in every corner drugstore, but in 1955 it's a little hard to come by.
Syncing to NIST or USNO would work, since both are atomic clocks :p
-Rimist (via Tapatalk)
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I'm sure that in 1985 plutonium is available in every corner drugstore, but in 1955 it's a little hard to come by.
We are talking about Back to the Future right?
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Use your cell phone or a gps unit for time. All cell towers are sync'd with gps, which is sync'd with UTC (universal time coordinated -word order is thanks to the French...).
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I'm sure that in 1985 plutonium is available in every corner drugstore, but in 1955 it's a little hard to come by.
We are talking about Back to the Future right?
Yes
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Thanks everyone, but I know how to manually set the time, I just get a bit ocd about the time not syncing exactly, and keep retrying in order to account for my reaction time, which of course inevitably varies.
-Rimist (via Tapatalk)
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and don't forget 'drift'. :)
drift is what bothers me much. I am confident that the Aeon is well-designed and has very little drift, but I get annoyed that no matter how often I set my new-fangled car to the time on my cell phone, i soon have 2 minutes discrepancy.
and this is a case where my car has a built-in gps. could they set the car's clock based on the gps...? apparently, not.
:)
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Time is relative
Don't sweat it
The universe does not have a clock
breathe deeply and relax
LOL
Rick R.
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My Aeon at work gains a second every 3 months. I reset it at the DST changes.
I haven't looked at the RTC chip pinouts but perhaps if you were THAT concerned about it, you might be able to change bump it forward or back by one second.
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My Aeon at work gains a second every 3 months. I reset it at the DST changes.
maybe the clock you reference it with loses a second every three months?
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It's the staggered change that drives me nuts, when you have two or more clocks visible and slightly out of sync. It actually annoys me more than the audio delay between cable tv and digital cable tv on the same channel.
-Rimist (via Tapatalk)
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You can remove the DS32kHz chip and feed a 32768Hz TTL signal into pin 12 (pin 4 is GND). It can come from your caesium or rubidium standard or a GPS-disciplined oscillator...
/mike
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My Aeon at work gains a second every 3 months. I reset it at the DST changes.
I haven't looked at the RTC chip pinouts but perhaps if you were THAT concerned about it, you might be able to change bump it forward or back by one second.
WOW! that inaccurate huh!
Read this I found to get an ideal of how accurate this is:
Crystal Clock accuracy is defined in terms of ppm or parts per million and it gives a convenient way of comparing accuracies of different crystal specifications.
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The following headings give practical calculations showing the typical errors you will encounter when using a clock of a specific type with a specific accuracy.
How good is a 1% accurate clock ?
If you look at a day's worth of timekeeping then you have 24 x 60 x 60 = 86400 seconds in a day. So the maximum error after a day has passed is 1% of 86400 = 864 seconds = 14 minutes!
How good is a typical crystal ?
A typical crystal has an error of 100ppm (ish) this translates as 100/10e6 or 0.001% (its the same number expressed as a percentage). So the total error on a day is 86400 x 0.01%= 8.64 seconds per day so in a month you would loose 30x8.64 = 4.32 minutes per month.
How good is a watch crystal ?
A watch crystal has an error of 20ppm (ish), but you have to design the board layout well, this translates as 20/10e6 (0.002%) which gives an error over a day of 86400 * 0.002% = 1.73 seconds per day so in a month it looses 30x1.72 = 51 seconds or 1 minute a month (approx).
The modern pic chips have 1% clocks, this is why I use the $8 clock device on the Aeon. So you see 1/3rd of a second per month is fairly accurate as clocks goes.
RJ
Sent from my charge on tapatalk
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Hmmm,
It also seems that a day is not exactly a day as the Earth doesn't quite spin perfectly, but rather wobbles on its axis. And even after taking that into account, the average day is not quite 24 hours, which results in the international standards people evaluating whether or not to add a leap second to UTC and GPS every 6 months. It looks like leap second #35 will be added on June 30th of this year... That makes 35 seconds in 50 years...
RM
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I'm sticking with my Casio wristwatch which sets the time automatically every night. I don't know how it does it I just know that I have not set the time on it in over 5 years. Even for daylight savings time. Better living thru science / technology I say. And it was only about $35 years ago.
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I use www.time.gov for my checks.
And RJ - I'm perfectly happy with the accuracy. Putting a temperature compensated oscillator on the board is a great idea.
It is on my wall at work and many express an interest until they hear about soldering.
Jon