Hi sebastian baez
The low power mode that require your application depends totally in the kind of sensor that you are using and in how you require your application to work. For example there are sensors that have specific interrupt pins that can wake up your MCU with a GPIO pin, there are others sensors that you can read the value as an analog measure, so maybe you set your MCU to wake up every specific time and read the value, as I mentioned, it depends in your sensor and application.
I recommend you to check the following links, here they explain the modules that are available in different low power modes and how you can set them for your application:
www.nxp.com/assets/documents/data/en/application-notes/AN4503.pdf
https://developer.mbed.org/media/uploads/GregC/an4470-using_low-power_modes_with_kinetis_mcus.pdf
Have a great day,
Jorge Alcala
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