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S32K118 FlexIO

Hello.

I would like to consult about implementing both-edge detection for motor Hall sensor signals using the FlexIO module on S32K118.

Currently, I need to capture both rising and falling edges of three Hall feedback signals from the BLDC motor. I am trying to configure FlexIO pins as input capture channels. However, I am confused about how to set FlexIO to detect both rising and falling edges simultaneously.

Could you share the proper FlexIO timer and shifter configuration workflow for dual-edge capture。Besides.I also want to know if interrupts can be triggered on every edge, and whether there are known limitations or precautions when using FlexIO for Hall signal sampling on the S32K118 platform. Thank you very much.

Re: S32K118 FlexIO

Hello @Niuyanlin,

If application is Hall sensor in BLDC motor feedback, I suggest looking into the FTM module instead.

The following application note mentions how to configure the module for single and dual edge capture, and how to generate a capture interrupt: AN5303: Features and Operation Modes of FlexTimer Module on S32K – Application Note.

"The Hall sensors are connected to the channels of the independent FTM (FTM_CHx). The FTM can then detect both the falling and rising edges of the Hall sensor signals and generate a capture interrupt."

FlexIO, by contrast, requires constructing input capture behavior indirectly through timer-decrement modes, and it can work, but in my opinion, FTM module is better suited.

Best regards,
Julián