A method of marking an egg is disclosed and comprises applying radiant energy to the shell of an egg so as to cause discoloration of the eggshell, thereby forming a marking comprising at least a traceability code and a freshness date. The intermediate substrate is positioned between the first active surface of the first semiconductor die and the second active surface of the second semiconductor die such that a first surface of the intermediate substrate faces the first active surface and such that a second surface of the intermediate substrate faces the second active surface. The exposure value by the incident light and an upper and a lower limit values of the latitude are displayed on a display device. A control block can adjust the resonant frequency of the LC circuit based at least in part on the indicator of RSSI.