Patent ID: 8810391
Filing Date: 2014-08-19
Classification: G06K,G07C

Abstract:
1. A method of sensing exposure to one or more of a plurality of environmental factors, comprising steps of: an exposing step of exposing a code circuit to at least some of the environmental factors, the code circuit disposed over a substrate and including a plurality of sensor patches, each sensor patch having a respective electrical state that changes with exposure to one of the environmental factors, so that the code circuit has an electrical state; a checking step of passing an electrical excitation signal through the code circuit, and detecting a corresponding received electrical signal, using a transceiver formed on a transceiver substrate separate from and disposed over the substrate, wherein the transceiver includes a controller and the received electrical signal depends on the excitation signal and the electrical state of the code circuit; a storing step of using the controller, automatically storing the received electrical signal or a representation thereof in a memory; and a repeating step of using the controller, automatically repeating the checking and storing steps after one or more selected time intervals; and wherein: