Soeks Quantum

Hi Mattia
Welcome to radmon.org!
First thing to do is see if we can get a serial stream of CPM data from the counter when it's plugged into your PC.
Have a look through the manual. Is there any mention of connecting to a PC and serial device baudrate. Do any devices come up in Device Manager when you plug it in?

Ok, next you need to use a serial terminal program (RealTerm?) to see what information is being sent over the COM port. Use default port settings and 9600 baud rate.
Usually, the CPM is sent every 30s or so, as a number.
We need to check that the data sent is in the format expected.
When you get some data to appear in the terminal from the calculator, cut and paste it here.

This is the manual for the Soeks Quantum (English about half way through)
https://drive.google.com/file/d/1KrVLxHPyz0uJj0xt4j4KL1Sb_lFKfC-J/view

I have had a look but it states nothing about CPM or other real time live output. Also everything in the manual is stated as uSv with no mention of CPM. It does mention not to connect the USB whilst there are non-rechargeable or no batteries installed. Would be best to fit rechargeables if connecting to a computer or external USB PSU.