Energy-autonomous battery-free system for smart irrigation

An irrigation system, comprising:

• an inlet pipe configured to receive pressurized water;
• a first controllable valve having a first valve inlet coupled in fluid communication with the inlet pipe to receive the pressurized water therefrom and having a first valve outlet coupled in fluid communication with an outlet pipe;
• a first valve driver configured to control the first controllable valve in response to a first control signal;
• a second controllable valve having a second valve inlet coupled in fluid communication with the inlet pipe to receive the pressurized water and having a second valve outlet;
• a second valve driver configured to control the second controllable valve in response to a second control signal;
• a power harvester having a harvester inlet coupled in fluid communication with the second valve outlet and having a harvester outlet coupled in fluid communication with a drain pipe, the power harvester configured to generate electrical power at a power output in response to pressurized water flowing therethrough;
• an energy storage unit electrically coupled between the power output and ground and configured to store a generated voltage thereacross;
• comparison circuitry configured to compare the generated voltage to at least one threshold and to generate at least one comparison output signal indicating whether the generated voltage is greater than the at least one threshold and whether the generated voltage is less than the at least one threshold;
• and control circuitry configured to:
• generate the second control signal such that the second valve driver causes the second controllable valve to permit the pressurized water to flow therethrough when the comparison circuitry indicates that the generated voltage is less than the at least one threshold, thereby causing generation of the electrical power by the power harvester when the comparison circuitry indicates that the generated voltage is less than the at least one threshold;
• and generate the second control signal such that the second valve driver causes the second controllable valve to prevent the pressurized water from flowing therethrough when the comparison circuitry indicates that the generated voltage is at least equal to the at least one threshold, thereby ceasing generation of the electrical power by the power harvester when the comparison circuitry indicates that the generated voltage is at least equal to or greater than the at least one threshold.