Converting PULSIN reading to RPM, from PC Fan?

[Acetronics2]

1) https://noctua.at/pub/media/wysiwyg/...hite_paper.pdf

2) @ these very low frequencies, the use of a divider per 2 ( so ... to measure the rotation period ! ) and using interrupts to drive a custom counter is to consider ...

aside that that wouldn't interfere much with the general timing ...

Now, being too accurate to measure a PC fan speed is somewhat a nonsense ... ( except for some geeks ... )

Alain

[Ioannis]

Maybe you mean x2 instead of divide by 2.

Ioannis

[Acetronics2]

Maybe you mean x2 instead of divide by 2.

Ioannis

Hi, Ioannis

No, no ... it's not an error : if you divide the pulse train per 2 ( D Flip-flop ...) ... the High or low pulse you get @ output has the exact rotation period ... ( remember how you did that with ol' 74 or 4000 logic chips ... )
rising edge fires the counter ... falling edge stops it.

easy then to care with an IOC interrupt stubb ...


Best Regards
Alain

[Ioannis]

I was thinking in terms of frequency and the low frequency you stated pushed me into that error. Sorry...

Thanks for the clarification.
Ioannis

[Acetronics2]

I was thinking in terms of frequency and the low frequency you stated pushed me into that error. Sorry...

Thanks for the clarification.
Ioannis

You're Welcome Ioannis ...

AND we are old friends !!!



Alain

[Ioannis]

Yeap! That's right! Nice picture with the two grands! Well I hope I don't look that old though...

Ioannis