> To get accurate speed readings for my bicycle speedometer
> project, I have to count how long it will take the wheel to turn
> rather than how many times it has turned in x seconds. I want
> a 1 second speed update rate so to go about it, I need to count
> how many milliseconds it takes for the wheel to spin once.
> That way, I can get an accurate speed reading.

A 32 bit  free running counter over the prescaler giving 10KHz. On
sensor event store the counter's value. Store last 4 values. That's
it. On a display interrupt get the difference between first and 4th
values, that is total time span for the last 3 rotations, calculate
and show the speed.

And, please, don't ask how to organize a 32 bit free running counter,
what's prescaler, why you need an interrupt to display the result etc.
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