Arduino Simulink Real Time FFT with piezoelectric sensor

For my final project I need to measure vibration using arduino with piezoelectric sensor.I need to find the frequency of the sensor values.I prepared a model like in the picture but all scopes give the same values.Is it supposed to be like this or did I make a mistake?

[El mehdi Ait Moh]

i have same project , can i get some help pls

[Omer Faruk]

i have also same project have you done it?