A switch actuation detection unit comprising a switch actuation voltage reception terminal (20, RC_IN) for receiving a switch actuation voltage (V_DETECT) generated in response to an operation of one of a plurality of switches (B1-B6) and a logic circuit with - a first port (PORT 1) being connected to the switch actuation voltage reception terminal (20, RC_IN), with - a second (PORT 2), with - a Zener diode, wherein a first terminal of the Zener diode is connected to the switch actuation voltage reception terminal (20, RC_IN) and a second terminal of the Zener diode is connected to the second port (PORT 2), and with - a signal port for providing a plurality of pre-determined switch state signals indicating which one of the plurality of switches (B1-B6) is operated, wherein the switch actuation detection unit is configured to provide - a normal mode when the switch actuation voltage (V_DETECT) is less than a pre-determined port saturation voltage, and - a saturation mode when the switch actuation voltage (V_DETECT) exceeds the pre-determined port saturation voltage, such that - in the normal mode, the logic circuit provides the pre-determined switch state signal according to the switch actuation voltage (V_DETECT) at the first (PORT 1), and - in the saturation mode, the Zener diode transmits a shifted voltage to the second port (PORT 2), the shifted voltage being generated according to the switch actuation voltage (V_DETECT) and to a predetermined Zener breakdown voltage, and the logic circuit provides the pre-determined switch state signal according to the pre-determined port saturation voltage at the first port (PORT 1) and the shifted voltage at the second port (PORT 2). a switch actuation voltage reception terminal (20, RC_IN) for receiving a switch actuation voltage (V_DETECT) generated in response to an operation of one of a plurality of switches (B1-B6) and a logic circuit with - a first port (PORT 1) being connected to the switch actuation voltage reception terminal (20, RC_IN), with - a second (PORT 2), with - a Zener diode, wherein a first terminal of the Zener diode is connected to the switch actuation voltage reception terminal (20, RC_IN) and a second terminal of the Zener diode is connected to the second port (PORT 2), and with - a signal port for providing a plurality of pre-determined switch state signals indicating which one of the plurality of switches (B1-B6) is operated, - a first port (PORT 1) being connected to the switch actuation voltage reception terminal (20, RC_IN), with - a second (PORT 2), with - a Zener diode, wherein a first terminal of the Zener diode is connected to the switch actuation voltage reception terminal (20, RC_IN) and a second terminal of the Zener diode is connected to the second port (PORT 2), and with - a signal port for providing a plurality of pre-determined switch state signals indicating which one of the plurality of switches (B1-B6) is operated, - a normal mode when the switch actuation voltage (V_DETECT) is less than a pre-determined port saturation voltage, and - a saturation mode when the switch actuation voltage (V_DETECT) exceeds the pre-determined port saturation voltage, such that - in the normal mode, the logic circuit provides the pre-determined switch state signal according to the switch actuation voltage (V_DETECT) at the first (PORT 1), and - in the saturation mode, the Zener diode transmits a shifted voltage to the second port (PORT 2), the shifted voltage being generated according to the switch actuation voltage (V_DETECT) and to a predetermined Zener breakdown voltage, and the logic circuit provides the pre-determined switch state signal according to the pre-determined port saturation voltage at the first port (PORT 1) and the shifted voltage at the second port (PORT 2).