An automatic irrigation controller that waters plants only when needed. A soil-moisture sensor checks the pot/bed, and a microcontroller switches a small pump or solenoid valve via a relay/MOSFET. You can set moisture thresholds, add a daily schedule, and keep a manual override for safety. Optional Wi-Fi (IoT) lets you see moisture levels, tank level, and pump status on your phone—reducing over/under-watering and saving water.

Parts Used:

1. Microcontroller: Arduino Uno/Nano or ESP32 (Wi-Fi built-in)
2. Soil Moisture Sensor (Capacitive type): More durable, less corrosion than resistive
3. Pump / Solenoid Valve: 5–12 V DC submersible pump or valve for drip lines
4. Driver & Switching: Relay module or N-MOSFET + flyback diode
5. Power Supply: 5 V for controller; 5–12 V for pump/valve (separate rail recommended)
6. Tubing & Drippers/Emitters: For distribution to pots/beds
7. Water Tank Level Sensor (Float/Probe) (Optional): Dry-run protection
8. Flow Sensor (Optional): Monitors delivered water volume
9. Environmental Sensors (Optional): DHT11/DHT22 for temp/humidity, LDR for daylight
10. RTC Module (Optional): DS3231 for time-based watering windows
11. Display/Interface (Optional): OLED/LCD, buttons for setpoint & manual ON/OFF
12. Enclosure & Wiring: Waterproof box, connectors, fuse, check valve/filters