Hi
which device should I consider if I want a really precise clock?
For example what would be better an Arduino uno(16MHz) or an Arduino zero(48MHz).
But speed is not as relevant as the precision.
Thanks
Hi
which device should I consider if I want a really precise clock?
For example what would be better an Arduino uno(16MHz) or an Arduino zero(48MHz).
But speed is not as relevant as the precision.
Thanks
Is that a clock signal or a clock as in real time clock ?
Always useful to include a description of what the projecty actually is, saves us time and you will get better answers.
What does "precise" mean to you? High time resolution? Low drift over long periods of time?
In either case, you need to provide quantitative requirements.
There are a lot of engineering types round here. We understand numbers not phrases like "really precise". Exactly what characteristics do you want your clock to have? In numbers.
Steve
I programm a timer interrupt. This signal is generated from the real clock?
I want it as exact as it can be for example an accuracy in the range of nanoseconds and of course also a low drift.
gab27:
I programm a timer interrupt. This signal is generated from the real clock?I want it as exact as it can be for example an accuracy in the range of nanoseconds and of course also a low drift.
You really do need to provide more details.
'range of nanoseconds' could be 1-5 or 50 - 200 or some other figure.
The accuracy of the timing will be down to the exact crystal used and it's tollerance\drift that could be difficult to determine.
The precision, how close you can adjust the tiomer to the value you want, would depend on the number of division steps available to the timer, this is nothing to do with 'accuracy'
A GPS receiver's 1Hz output is supposed to be pretty stable.
I'm reading the responses here, because I too am curious about the accuracy of timing using an Arduino Uno. Lots of questions back, rather than answers. It looks to me @Gab27 wants to know -- from the hard-number types who visit the forum -- is whether the implementation of timing circuits in the various Arduino platforms differs substantially. Is one more accurate than the others?
There you go, this will be very precise Cesium clock
yes that's the question: Is one more accurate than the others? (zero vs uno)
So do they have the same crystal or is one substantially better?
couldabin:
is whether the implementation of timing circuits in the various Arduino platforms differs substantially. Is one more accurate than the others?
The maximum resolution depends on the clock frequency, so a 48MHz board has a 3x higher resolution compared to a 16MHz Board.
The accuracy depends on the timing source. There are the internal oscillator (infos in the datasheet of the microcontroller), ceramic oscillator and quartz oscillators (again, the datasheet for the components is the source of choice)
Rule of thumb: Internal < Ceramic < Quartz < RTC-module (better quartz) < NTP < GPS
gab27:
yes that's the question: Is one more accurate than the others? (zero vs uno)
So do they have the same crystal or is one substantially better?
@couka -- that's very helpful. Thank you!
Give a man a clock, and he knows what time it is. Give a man two clocks, and he's not sure.
Thanks couka