Update simulation of vibration sensors

[dmiklic]

There have been changes to hardware:

• there is only one vibration sensor
• the sensor reading contains two arrays: frequency ad amplitude values of the main spectrum components (as computed by FFT)
• the Device field in the zeromq message has been changed to Fft

[dmiklic]

Pedro, can you please take a look at this tomorrow? I would like to use this workshop to update at least the simulator interface to match the interface of real CASUs.

[plsm]

I'll look at this.

[dmiklic]

Ok, great! I have changed the Device from 'Acc' to 'Fft', however, I'm now getting only empty readings.