I already posted something related to this topic and I already tried out a few things.
To the project:
I wanted to touch the surface of a wooden table and the sensor (attached below the table) should pick up the signal.
The table that I bought was 17mm thick, hence I had to reduce the thickness.
I carved out parts of the table (picture) and the current thickness is now 1.1mm.
I also modified the prescaler value for the bar sensor:
I just took the raw_multi_print script for the arduino and added only the following lines.
(I also tried lower values for the prescaler however it did not pick up the signal)
I'm not an Arduino or trill sensor expert therefore maybe someone of you can find why it doesn't work very well or has maybe some suggestions to get it running.