A near-field communication (NFC) system may include a plurality of NFC devices each including a housing, a power source carried by the housing, at least one input device carried by the housing and assigned to a designated device function, an NFC circuit configured to wirelessly communicate using an NFC communications protocol, and a processor. The processor may be configured to initiate the designated device function based upon a first input pattern of the at least one input device, switch the NFC circuit between a higher power state and a lower power state at a first frequency, the NFC circuit in the higher power state being configured to generate an RF field to initiate NFC communications, and switch the NFC circuit between the higher and lower power states at a second frequency based upon a second input pattern of the input device(s) different from the first input pattern.