How can i capture rise edge to compute frequency?

[ricardcomas]

Hi, i m using a MKE06128VLK processor, i have a PWM signal, wich is a component to compute frequency? can i do it with a capture component?¿ i try to use it but i don't get work it.

thanks!

[hamed]

Hello ricardcomas

This MCU has built-in Pulse Width Timer (PWT) that is able to measure both positive and negative pulse widths and can be triggered at rising or falling edge. You can refer to page 495 on the reference manual for detailed information. Hope it helps.

[Alice_Yang]

Hello Ricard Comas,

Yes, you can use the Input Caputer mode to compute frequency.

In Input Caputer mode,when a selected edge occurs on the channel input, the current value of the FTM counter
is captured into the CnV register, therefore the measured period of the signal (e.g. rising edge to rising edge) is equal to difference of the captured values.

What about your problem ?

Note that the maximum frequency for the channel input signal to bedetected correctly is system clock divided by 4.

There is comment about using input caputer mode to compute frequency , you can have a loo。

capture_LDD-result       

Hope it helps,

Have a great day,
TIC

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