Grove Piezo Vibration calibration or debounce?

Hi there,
got my grove piezo vibration sensor.

Connected to my arduino wifi 101, it measures well… BUT it sends 0 and 1 constantly.
I tried to use the potentiometer to calibrate it… no luck.

When I turn it completely (seems endless one), at some point, I got only zeros OK.
I turn it a very bit, and it starts to redo the 01101010101001 things. even if I don’t move the sensor anymore.

Does someone have that too ?

I suggest you try the circuit and code given here Grove - Piezo Vibration Sensor | Seeed Studio Wiki with an ordinary Arduino UNO instead of the wifi 101. Also, adjust the on-board potentiometer.

I don’t understand why the arduino mkr would make it behaving differently.

I checked the value with serial monitor, the mkr wired to my computer.

I adjusted, and test with different potentiometer values, as I wrote.
Same.

I guess the sensor is broken.

May I ask which code you used?