[ntp:questions] ntpd -q and driftfile
hal-usenet at ip-64-139-1-69.sjc.megapath.net
Wed Mar 23 05:08:22 UTC 2011
>> oh, come off it. Your reaction time is nowhere near what ntp -q would
>> give you. Using ntp -q run once every hour, and assuming say a 20PPM
>> drift for the crystal, his clock would be out by less than a 100 ms due to the
>> drifting, and your reaction time with your watch ( and wyour watch) are
>> nowhere near that accurate.
>Actually, it is on the borderline of the achievable. You phase lock
>your finger bounces to the second ticks and just go that little further
>on the exact time. It's certainly good to 200ms and possibly good to 100ms.
That would be a fun project for a science fair.
Build a setup. Collect a lot of data.
How much does it vary? For one person, between people, ...
How close can you get if you are trying to set a clock?
Can you calibrate the person and subtract off a constant?
What if you get multiple samples?
Many years ago, my boss did that sort of stuff. I think he said that
normal reaction time from light-on to button-press was 250 ms. It's
faster if there is no penalties for false presses.
These are my opinions, not necessarily my employer's. I hate spam.
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