### Author Topic: Lowest frequency measured by Nano  (Read 1138 times)

#### acxysty

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##### Lowest frequency measured by Nano
« on: September 10, 2015, 09:07:58 AM »
Dear All

We need to monitor a sensor generating a low frequency signal ( 5 to 50 Hz).
Is it within the range of PULSEFREQUENCY function or is it too low ?

Regards

Thierry

#### support

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##### Re:Lowest frequency measured by Nano
« Reply #1 on: September 10, 2015, 09:45:27 AM »
Yes you can measure from 5Hz to 50Hz using the PULSEFREQUENCY function but the resolution is 1Hz.

You can achieve fractional frequency very accurately in this low frequency range if you use PULSEPERIOD function, which returns the period in 1us or 0.1us (configurable - see User's Manual).

The frequency will be the inverse of the period. So you can get down to 0.01Hz by:

F_requency = 100000000/PULSEPERIOD(1)

if PULSEPERIOD is configured to returns 1us.

So if F = 1234 means 12.34 Hz.
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