An electronic device comprising: - a sensor able to detect a predefined event; - a processing digital circuit connected to the sensor, the processing digital circuit being in an off state; - a power source connected to the sensor, - a switch positioned between the power source and the processing digital circuit; - -an event detection device connected to the sensor and configured to activate the switch to connect the processing digital circuit to the power source when the sensor detects the predefined event, so as to switch the processing digital circuit from the off state to an on state, wherein the processing digital circuit is configured to read in the on state a signal from the sensor when the sensor detects the predefined event and the processing digital circuit is configured to operate at least a predetermined task when it reads the signal from the sensor, wherein the event detection device is configured to deactivate the switch to disconnect the processing digital circuit from the power source once the at least a predetermined task has been operated, characterized in that said electronic device further comprises a circuitry change device connected to the event detection device and configured to detect a change within the electronic device, send an initiating signal to the event detection device, the event detection device being configured to connect the processing digital circuit to the power source, so as to switch the processing digital circuit from the off state to the on state, and the processing digital circuit being configured to send a configuration signal to the sensor, so as to pair the sensor with the processing digital circuit, wherein the change within the electronic device is a power source change and/or a sensor change and/or a processing digital circuit change. - a sensor able to detect a predefined event; - a processing digital circuit connected to the sensor, the processing digital circuit being in an off state; - a power source connected to the sensor, - a switch positioned between the power source and the processing digital circuit; - -an event detection device connected to the sensor and configured to activate the switch to connect the processing digital circuit to the power source when the sensor detects the predefined event, so as to switch the processing digital circuit from the off state to an on state, wherein the processing digital circuit is configured to read in the on state a signal from the sensor when the sensor detects the predefined event and the processing digital circuit is configured to operate at least a predetermined task when it reads the signal from the sensor, wherein the event detection device is configured to deactivate the switch to disconnect the processing digital circuit from the power source once the at least a predetermined task has been operated, characterized in that said electronic device further comprises a circuitry change device connected to the event detection device and configured to detect a change within the electronic device, send an initiating signal to the event detection device, the event detection device being configured to connect the processing digital circuit to the power source, so as to switch the processing digital circuit from the off state to the on state, and the processing digital circuit being configured to send a configuration signal to the sensor, so as to pair the sensor with the processing digital circuit, wherein the change within the electronic device is a power source change and/or a sensor change and/or a processing digital circuit change.