A piezoelectric sensor comprises a microcontroller, a plurality of piezoelectric sensor elements of which at least two are useable for producing a haptic signal by a voltage (HV) generated by a boost converter connected to each piezoelectric sensor element, and connected to a piezo channel of the microcontroller. A multiplexer individually controls each of the switches if an enable a signal is present. The microcontroller is configured to use each of the piezo channels as a sensor channel for reading sensor input from the respective piezoelectric sensor element and in response to detecting a sensor input in at least one of the piezo channels to set the enable signal at the increase voltage pin and/or the enable signal pin, and to set a signal to at least one piezo channel in which the sensor input was detected.