When to use ac coupling with sensors ?

Other Hardware General Electronics
1

Hello,

As I understand, most of the time resistive sensors (FSR and such) are DC coupled to Arduino inputs.

Are there situations where AC coupling would be useful with resistive sensors, even with a very low cutoff frequency ?

Thank you in advance.

2

Sure, for example to make drum/knock sensors. To detect hitting it, an AC coupling will do.
And piezo element as a sensor is in theory DC, but with normal use it is more as a AC sensor. So a AC coupling can be almost the same as DC for piezo.

3

Thanks Peter_n !