An energy harvesting module, comprising: a pendular unit subjected to external stresses applied to the module, the pendular unit comprising a beam that is elastically deformable in bending according to at least one degree of freedom, with a clamped end and an opposite free end coupled to an inertial mass; wherein the beam is a piezoelectric beam forming a mechanical-electrical transducer adapted to convert into an oscillating electrical signal a mechanical energy produced by oscillations of the pendular unit; and a power management circuit, adapted to rectify and regulate the oscillating electrical signal to output a stabilized direct power voltage or current, the energy harvesting module further comprising a circuit for monitoring the integrity of the beam, comprising: an acceleration sensor for providing an acceleration signal representative of the instantaneous acceleration of the beam in a direction perpendicular to a surface of the beam; a collecting and sampling circuit, adapted to receive the oscillating signal and the acceleration signal, and to provide a plurality of successive samples each containing an oscillating signal value associated with a concomitant acceleration value; a memory storing a transfer function describing the mechanical-electrical behavior of the beam, wherein said transfer function is a relation providing, for respective given values of a set of modelling parameters, an oscillating signal value as a function of a value of instantaneous acceleration of the beam; and a processor and a memory comprising instructions for causing the processor to execute a process comprising the following steps: a) receiving the plurality of said successive samples each containing an oscillating signal value associated with a concomitant acceleration value; b) applying these successive samples to said transfer function to derive therefrom a corresponding set of estimates of said modelling parameters from the oscillating signal and acceleration values of the successive samples; and c) deriving from said estimates of the modelling parameters at least one physical metric of the pendular unit and/or of the beam. a pendular unit subjected to external stresses applied to the module, the pendular unit comprising a beam that is elastically deformable in bending according to at least one degree of freedom, with a clamped end and an opposite free end coupled to an inertial mass; wherein the beam is a piezoelectric beam forming a mechanical-electrical transducer adapted to convert into an oscillating electrical signal a mechanical energy produced by oscillations of the pendular unit; and a power management circuit, adapted to rectify and regulate the oscillating electrical signal to output a stabilized direct power voltage or current, an acceleration sensor for providing an acceleration signal representative of the instantaneous acceleration of the beam in a direction perpendicular to a surface of the beam; a collecting and sampling circuit, adapted to receive the oscillating signal and the acceleration signal, and to provide a plurality of successive samples each containing an oscillating signal value associated with a concomitant acceleration value; a memory storing a transfer function describing the mechanical-electrical behavior of the beam, wherein said transfer function is a relation providing, for respective given values of a set of modelling parameters, an oscillating signal value as a function of a value of instantaneous acceleration of the beam; and a processor and a memory comprising instructions for causing the processor to execute a process comprising the following steps: a) receiving the plurality of said successive samples each containing an oscillating signal value associated with a concomitant acceleration value; b) applying these successive samples to said transfer function to derive therefrom a corresponding set of estimates of said modelling parameters from the oscillating signal and acceleration values of the successive samples; and c) deriving from said estimates of the modelling parameters at least one physical metric of the pendular unit and/or of the beam. a) receiving the plurality of said successive samples each containing an oscillating signal value associated with a concomitant acceleration value; b) applying these successive samples to said transfer function to derive therefrom a corresponding set of estimates of said modelling parameters from the oscillating signal and acceleration values of the successive samples; and c) deriving from said estimates of the modelling parameters at least one physical metric of the pendular unit and/or of the beam.