Hi.
Unfortunately, I never tried something like that.
Is that an ESP32-compatible sensor? Can you share a link to the sensor?
Regards,
Sara

Hi Sara, 
Many thanks for your reply.
I have build very simple rectifier from 4x LED without resistors and I have got some results ;P

I’m curious it is possible to build circuit for measuring ac from sensor? 
Link with sensor 
https://www.bosch-mobility.com/en/solutions/sensors/knock-sensor/
Best Regards 
Bartek

Hi.
Thanks for sharing the link.
Unfortunately, it’s definitely something that i’m not really familiar with..
I’m sorry that I can’t help much on this subject.
Regards,
Sara