Sensor-based interruption of an irrigation controller

1. A system for interfacing with an irrigation controller based on rainfall, the system comprising:

an interface unit including a housing and a control unit within the housing and configured to:

cause an interruption of one or more watering schedules executed by the irrigation controller, which is separate from the interface unit, based on signaling received from a rain sensor including hygroscopic material, when a sensed expansion of the hygroscopic material is above a set rainfall accumulation threshold parameter, the rain sensor being separate from the interface unit and the hygroscopic material being configured to expand in response to being contacted by the rainfall and to contract in response to an absence of the rainfall; and

remove the interruption after a completion of a predetermined interval of time after a sensed contraction of the hygroscopic material indicative of a rainfall stop;

wherein the control unit is configured to:

in response to the sensed contraction of the hygroscopic material indicative of the rainfall stop, initiate a timer configured to count down a remainder of time left on the predetermined interval of time of the interruption;

obtain an amount of expansion and contraction in the signaling from the rain sensor at intermittent intervals during a countdown, by the timer, of the remainder of time left on the predetermined interval of time of the interruption; and

at one of the intermittent intervals, reset the timer to restart a countdown of the remainder of time left on the predetermined interval of time of the interruption in response to a determination, by the control unit, that the amount of expansion and contraction of the hygroscopic material in the signaling received from the rain sensor at the one of the intermittent intervals indicates an expansion of the hygroscopic material relative to an amount of expansion and contraction received from the rain sensor at a preceding intermittent interval.

2. The system of claim 1 , wherein the predetermined interval of time of the interruption is one of pre-programmed into the control unit and preset by a user.

3. The system of claim 1 , wherein the predetermined interval of time of the interruption is at least 48 hours.

4. The system of claim 1 , wherein the control unit is configured to, at one of the intermittent intervals, permit the timer to continue the countdown of the remainder of time left on the interval of time of the interruption in response to a determination, by the control unit, that the signaling received from the rain sensor at the one of the predetermined intervals indicates a contraction of the hygroscopic material relative to an amount of expansion and contraction received from the rain sensor at a preceding intermittent interval.

5. The system of claim 1 , further comprising the rain sensor including the hygroscopic material configured to expand in response to being contacted by the rainfall and to contract in response to an absence of the rainfall.

6. The system of claim 1 , further comprising the irrigation controller configured to execute the one or more watering schedules.

7. The system of claim 1 , further comprising a switching device configured to receive one or more control signals from the control unit and to cause the interruption of the one or more watering schedules.

8. The system of claim 1 , wherein the hygroscopic material of the rain sensor includes at least one hygroscopic material disk.

9. The system of claim 1 , wherein the rainfall accumulation threshold parameter is a user-defined adjustable threshold.

10. The system of claim 1 , wherein the rainfall accumulation threshold parameter is preprogrammed into the control unit.

11. The system of claim 1 , wherein the interface unit further comprises a user interface integrated with the housing and comprising a plurality of user input devices coupled to the control unit and a user display coupled to the control unit.

12. A method for interfacing with an irrigation controller based on rainfall, the method comprising:

providing an interface unit including a housing and a control unit within the housing;

causing, via the control unit, an interruption of one or more watering schedules executed by the irrigation controller, which is separate from the interface unit, based on signaling received from a rain sensor including hygroscopic material, when a sensed expansion of the hygroscopic material is above a set rainfall accumulation threshold parameter, the rain sensor being separate from the interface unit and the hygroscopic material being configured to expand in response to being contacted by the rainfall and to contract in response to an absence of the rainfall;

removing, via the control unit, the interruption after a completion of a predetermined interval of time after a sensed contraction of the hygroscopic material indicative of a rainfall stop;

initiating, via the control unit and in response to the sensed contraction of the hygroscopic material indicative of the rainfall stop, a timer configured to count down a remainder of time left on the predetermined interval of time of the interruption;

obtaining, via the control unit, an amount of expansion and contraction in the signaling from the rain sensor at intermittent intervals during a countdown, by the timer, of the remainder of time left on the predetermined interval of time of the interruption;

determining, via the control unit, that the amount of expansion and contraction of the hygroscopic material in the signaling received from the rain sensor at one of the intermittent intervals indicates an expansion of the hygroscopic material relative to an amount of expansion and contraction received from the rain sensor at a preceding intermittent interval; and

resetting via the control unit and at the one of the intermittent intervals, the timer to restart a countdown of the remainder of time left on the predetermined interval of time of the interruption.

13. The method of claim 12 , further comprising one of pre-programming into the control unit and permitting a user to preset the predetermined interval of time of the interruption.

14. The method of claim 12 , wherein the predetermined interval of time of the interruption is at least 48 hours.

15. The method of claim 12 , further comprising:

determining, via the control unit, that the signaling received from the rain sensor at one of the intermittent intervals indicates a contraction of the hygroscopic material relative to an amount of expansion and contraction received from the rain sensor at a preceding intermittent interval; and

permitting, via the control unit and at the one of the intermittent intervals, the timer to continue the countdown of the remainder of time left on the predetermined interval of time of the interruption.

16. The method of claim 12 , further comprising providing the rain sensor including the hygroscopic material configured to expand in response to being contacted by the rainfall and to contract in response to an absence of the rainfall.

17. The method of claim 12 , further comprising providing the irrigation controller configured to execute the one or more watering schedules.

18. The method of claim 12 , further comprising providing a switching device configured to receive one or more control signals from the control unit and to cause the interruption of the one or more watering schedules.

19. The method of claim 12 , wherein the hygroscopic material of the rain sensor includes at least one hygroscopic material disk.

20. The method of claim 12 , further comprising permitting a user to define and adjust the rainfall accumulation threshold parameter.

21. The method of claim 12 , further comprising preprogramming the rainfall accumulation threshold parameter into the control unit.

22. The method of claim 12 , wherein the providing step further comprises providing a user interface integrated with the housing and comprising a plurality of user input devices coupled to the control unit and a user display coupled to the control unit.

23. A system for interfacing with an irrigation controller based on rainfall, the system comprising:

an interface unit including a housing and a control unit within the housing and configured to:

cause an interruption of one or more watering schedules executed by the irrigation controller, which is separate from the interface unit, based on signaling received from a rain sensor including hygroscopic material, when a sensed expansion of the hygroscopic material is above a set rainfall accumulation threshold parameter, the rain sensor being separate from the interface unit and the hygroscopic material being configured to expand in response to being contacted by the rainfall and to contract in response to an absence of the rainfall; and

remove the interruption after a completion of a predetermined interval of time after a sensed contraction of the hygroscopic material indicative of a rainfall stop;

wherein the control unit is configured to:

at the time the interruption is caused, to initiate a timer configured to count down a remainder of time left on the predetermined interval of time of the interruption;

to obtain an amount of expansion and contraction in the signaling from the rain sensor at intermittent intervals during a countdown, by the timer, of the remainder of time left on the predetermined interval of time of the interruption;

to reset the timer in response to a determination, by the control unit, that the amount of expansion and contraction of the hygroscopic material in the signaling received from the rain sensor at the one of the intermittent intervals indicates an expansion of the hygroscopic material relative to an amount of expansion and contraction received from the rain sensor at a preceding intermittent interval; and

at one of the intermittent intervals, to permit the timer to continue the countdown of the remainder of time left on the interval of time of the interruption in response to a determination, by the control unit, that the signaling received from the rain sensor at the one of the predetermined intervals indicates a contraction of the hygroscopic material relative to an amount of expansion and contraction received from the rain sensor at a preceding intermittent interval.