Misting and watering system controller with light sensistive detector

摘要

System and method for supplying water to plants. A photodetector detects light adjacent the plants and a threshold circuit generates a first signal representative of a first state when the level of illumination of the detected light is less than a threshold level and generates a second signal representative of a second state when the level of illumination of the detected light is greater than the threshold level. A processor is responsive to the first and second signals for anticipating approximately when the detected light will next change from the first state to the second state and approximately when the detected light will next change from the second state to the first state. A counter circuit responsive to the processor generates an initiate signal and a terminate signal. The counter circuit generates the initiate signal a first period of time before or after the anticipated change from the first state to the second state and generates the terminate signal a second period of time before or after the anticipated change from the second state to the first state. A valve control circuit, responsive to the initiate signal for beginning a sequence of alternating on and off periods and responsive to the terminate signal for ending the sequence, controls a valve arrangement which supplies water to the plants.