Methods and systems are disclosed for integrating LC circuits into a user's jewelry for controlling systems such as computer games. The resonant frequency of the circuit at each of multiple rings worn by the user may be adjustable. A secondary coil within each ring may be moved in relation to the magnetic field generated by a primary coil that may be part of another piece of jewelry, such as a watch or a bracelet, to generate control signals. The magnetic field may inductively couple and power the rings, which may each contain an LC tank circuit. If powered, each of these circuits may oscillate at its resonant frequency. A receiver system may comprise an antenna and a tuning circuit to detect a resonant frequency as an input to control moves of a character within a game, for example for use with heads-up displays (HUDs) for augmented reality applications.