Abstract: A capacitive proximity sensor (1) comprising a microcontroller (20) which is configured to perform measurements in a repetitive predetermined sequence, said sequence comprising a series of N consecutive measurements, N being a natural integer greater than or equal to three, wherein, with the period between two consecutive analog-to-digital conversions of the first measurement of the series being called a reference period, the period between two analog-to-digital conversions of a measurement m of the series, m being a natural integer comprised between 2 and N, is defined as being equal to the reference period plus the product of (m?1) and a predetermined additional unitary period. The additional unitary period is equal to half the period needed to shift a noise sensitivity peak of the sensor (1) by half its frequency width.

Abstract: A device for a presence detection system for detecting the presence of a user close to a motor vehicle is configured to: activate a piezoelectric element during an “awake” time interval to stabilize the piezoelectric element; then, control the supply of voltage to an oscillator and supply the oscillator with a reference electrical signal forming a current voltage reference, so the transceiver circuit transmits a signal during what is called a “transmission” time interval; during the transmission time interval, measure the frequency of a reflected signal resulting from the transmitted signal, measure the frequency of the transmitted signal, and determine a corrected reference based on the measured frequency of the transmitted signal, allowing the oscillator to operate at a target frequency value. This allows limiting the energy consumption of a transceiver device used to detect the presence of a user close to a motor vehicle.

Abstract: A device for a presence detection system for detecting the presence of a user close to a motor vehicle is configured to: activate a piezoelectric element during an “awake” time interval to stabilize the piezoelectric element; then, control the supply of voltage to an oscillator and supply the oscillator with a reference electrical signal forming a current voltage reference, so the transceiver circuit transmits a signal during what is called a “transmission” time interval; during the transmission time interval, measure the frequency of a reflected signal resulting from the transmitted signal, measure the frequency of the transmitted signal, and determine a corrected reference based on the measured frequency of the transmitted signal, allowing the oscillator to operate at a target frequency value. This allows limiting the energy consumption of a transceiver device used to detect the presence of a user close to a motor vehicle.