Method for detecting the presence of a liquid in a container by means of a near-field communication circuit

A method for detecting the presence of a liquid in a container by a near-field communication circuit that includes at least one coil surrounding the container. The method being designed to adopt a first communication mode, in which the circuit can communicate with a compatible object arranged in the container, and a second detection mode for detecting a liquid. The second detection mode including the following steps: measuring at least one so-called present physical quantity by the coil of the circuit, the present physical quantity being representative of the dielectric permittivity of the medium bounded by the container, and transmitting a signal indicating detection of a liquid in the container if the present physical quantity crosses a predetermined reference threshold.