A flow meter device is coupled to at least one sensor that measures a flow speed and provides status signals from which the flow speed can be determined. The flow meter receives and processes the flow measurement data provided by the at least one sensor. The at least one sensor is enabled at defined time instances for a defined interval time. The flow meter receives at least one status signal from the sensor each time the sensor is enabled and processes the status signals to generate a trigger event when certain conditions arise. A processing unit wakes up from a sleep mode when a trigger event is generated by the flow meter device.