Piezoelectric measuring device for motor vehicle

A device for measuring a parameter, for a motor vehicle, said device comprising a main module and a remote module said main module comprising a control stage and a piezoelectric transmitter that is configured to transmit ultrasonic signals, said control stage being configured to electrically power said piezoelectric transmitter and to command transmission of signals by said piezoelectric transmitter, said remote module comprising a piezoelectric receiver configured to receive ultrasonic signals transmitted by the piezoelectric transmitter, a sensitive element configured to measure said parameter and to generate a measurement signal(S) comprising at least one value of said parameter, and a measurement stage that is connected on the one hand to the piezoelectric receiver and on the other hand to said sensitive element, and that is configured to collect and store the energy of the signals received by the piezoelectric receiver with a view to electrically powering the sensitive element, to receiving a measurement signal (S) generated by the sensitive element, to extracting from said received measurement signal (S) the values of the measured parameter and to commanding transmission of signals comprising the extracted parameter values.