Patent ID: 7966153

Claim:
An intelligent irrigation rain sensor comprising: a rain sensor unit for capturing and interacting with rainwater, said rain sensor unit comprising: rain catcher reservoir having an open upper end for catching rain, an interior volume for holding rainwater and a metering orifice at a lower end of the interior volume for metering rainwater from the interior volume as individual water droplets; a droplet detector comprising a pair of detection electrodes and disposed below the metering orifice for interacting with the individual water droplets metered from the rain catcher reservoir; a rainfall threshold adjustment interface for adjusting the predetermined rain threshold count as an amount of rainfall; and a dry timer for comparing a time period subsequent to a communication of a rain signal to irrigation controller with a predetermined drying time period and for initiating the communication of a dry signal to the irrigation controller; a sensor control unit for monitoring the rain sensor unit and communicating with irrigation controller, said sensor control unit comprises: a detection control coupled to the droplet detector for sensing interactions between water droplets and the droplet detector, by sensing a change in an electrical property at the detection electrodes, and for generating a water droplet detection indication; and a transfer-event manager for recognizing a transfer event and for initiating the communication of the rain signal to the irrigation controller, wherein the transfer event is based on a comparison of a water droplet detection indication count from the counter and a predetermined rain threshold count; and a counter coupled to the detection control for receiving water droplet detection indications and counting the water droplet detection indications; and a media port for communicating a rain signal to irrigation controller.