Automatic Plant Watering
Sensor-driven irrigation using soil-moisture readings, threshold logic and relay-controlled water delivery.
2023
Arduino Uno · Moisture feedback and pump switching.
Moisture-driven irrigation
An Arduino Uno uses soil-moisture readings to decide when a water pump should run. A relay separates the microcontroller's low-power decision signal from pump switching. Repeated measurements close the feedback loop as watering changes the soil condition.
Technology and role
Scroll horizontally to compare.
| Component | Role |
|---|---|
| Soil-moisture sensor | Supply the moisture input used for the watering decision. |
| Arduino Uno · C++ · Arduino IDE | Read the sensor and evaluate threshold logic. |
| 5 V relay · water pump | Switch water delivery from the controller output. |
Control mechanism
- Read soil condition and compare it with the configured watering threshold.
- Switch the pump through the relay when the measured soil condition requires watering.
- Continue measurement during the feedback cycle and stop delivery when the threshold condition is restored.
- Calibrate the useful threshold against the sensor and soil conditions rather than treating every installation as equivalent.
Engineering decisions and deliverables
Threshold control keeps the watering decision inspectable and suitable for a small embedded circuit. The sensor, controller, relay and pump each have a distinct responsibility. The project combines the component circuit with a repeated sensing/actuation loop, making the effect of water delivery observable at the next reading.