Abstract: A sensor and method for sensing moisture content of a medium such as soil is disclosed. In an embodiment, the sensor includes a sensing circuit, a processing module, a register, and a communications interface for communicatively coupling the sensor to an external communications device. In use, the sensing circuit generates a sensed signal having a signal parameter value attributable to the moisture content of the medium. The processing module processes the signal parameter value to provide, at an output, a scaled data value. The register stores a sensor identifier for the sensor and the communications interface is capable of communicating the scaled data value and the sensor identifier to the external device. An irrigation control system is also disclosed.