Abstract: An electronic system includes a first LC oscillator connected to a first general-purpose input/output (GPIO) circuit and a second LC oscillator connected to a second GPIO circuit. A threshold generator is coupled to an input of the comparator. A control circuit is configured to control a measurement phase comprising a first capture phase and a second capture phase. A microcontroller is coupled to the control circuit and a power management circuit is configured to switch-off the microcontroller following activation of the control circuit by the microcontroller. The control circuit is configured to control the application of an excitation signal to the each oscillator via the respective GPIO circuit, control the GPIO circuit so that oscillations of the oscillator are provided to the comparator, and count, based on an output of the comparator, a number of oscillations in the oscillator exceeding a threshold output by the threshold generator.