A wireless sensor includes an antenna, a sensing integrated circuit (IC), and a power supply impedance altering element. The antenna is operable to receive an inbound radio frequency (RF) signal and to transmit an outbound RF signal. The sensing IC includes a power supply, a first power supply connection, and a second power supply connection. The power supply impedance altering element is coupled to the first and second power supply connections and is coupled to sense a condition of an item. The sensing IC is operable to detect an impedance change of the power supply based on an effect of the power supply impedance altering element. The sensing IC is further operable to convert the impedance change into a digital value that represents the condition of the item. The sensing IC is further operable to output, via the antenna, the digital value or a representation of the condition.
