Systems and methods for detecting an opening and closing of an object, such as a door or window. The methods comprise: causing a piezoelectric transducer to oscillate in response to an opening of the object; harvesting energy generated as a result of the piezoelectric transducer's oscillation to power a transceiver; and transmitting, from the transceiver to a remote device, information indicating that the opening of the object has been detected by a wireless sensor coupled to the object. The information may specify a logical address linked to a physical location of the object (e.g., a MAC address).