🌿 Automatic Plant Irrigation System with Ultrasonic and Temperature Sensors

This Arduino-based system automates plant irrigation by monitoring the water level in a tank and the soil temperature using analog and ultrasonic sensors. The system intelligently activates relays to control irrigation devices. If water is insufficient, it alerts the user via buzzer and blinking LED. An IR sensor interrupt provides emergency shutdown functionality.

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🔧 Components Used

• Arduino Uno (or compatible)
• HC-SR04 Ultrasonic Distance Sensor
• 3 Analog Temperature Sensors (e.g., LM35)
• Yellow LED
• Buzzer
• 3 Relays
• IR Sensor (for emergency interrupt)
• Jumper wires and optional resistors

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🖥️ Pin Configuration

Component	Arduino Pin
IR Emergency Sensor	D3
Water Level Sensor	A0
Temperature Sensor 1	A1
Temperature Sensor 2	A5
Temperature Sensor 3	A3
Yellow LED	D8
Buzzer	D12
Relay 1	D4
Relay 2	D6
Relay 3	D7
Ultrasonic Sensor	Trigger: D11, Echo: D10

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🧠 System Logic

• The ultrasonic sensor measures distance to check tank fill level.
• If distance < 12 cm and ToF > 0.3 ms, the system:
  • Reads 3 temperature sensors.
  • Activates irrigation relays based on temperature thresholds and time logic.
• If the tank is empty:
  • Disables all relays
  • Triggers alerts via buzzer and LED
• An IR sensor provides emergency shutdown by triggering an interrupt.
• A debug mode can print all sensor values via Serial Monitor.

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🔄 Changelog (v5.0.0)

• 🧠 Added rele_control lambda function for smart relay control
• ⏱️ Time-based logic using millis() for activation delays
• 🚨 Integrated IR sensor interrupt for emergency stop
• 🔔 Improved audio-visual feedback when tank is empty
• 🐞 Debug mode enabled via #define DEBUG_LEVEL

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🐞 Debug Mode

To enable serial debug output:

#define DEBUG_LEVEL 1