reverse engineering my old piezo shock detector.

[spikey1973]

Oke hello to all.

I recently decided to pick back up a small project I started on a few years ago.
While starting this, I decided I want to redo the electronics part of this prototype because it is not really usable they way I had it in mind.

An important part of the project is a shock detector pased on a piezo disk.
This is not only to determin if there is a shock but also to measure the intensity of the shock by measuring the voltage on the signal line to a wemos s2 mini board.
To make sure I don't fry the S2 board/pin I (tried to) make a small tool to max the voltage to 3.3V and keep it positive.

Since I have to re-make this too and I lost all my documentation and the original link to the forum thread (here / somewhere else?) 
So I started to reverse engineer my "own" work.

I tried to make a schematic drawing of this but I have big doubts about it being correct. Either by my reversed-enginering or if I made it correctly originally.
As said, unfortunately, I can't find the former forum thread back, or even find a similar "network" design.

So I was wondering if someone here can help me out a little, with getting the diagram correct.

In advance, thanks for any offered help.

Kind greats. Matthieu