Step into Smart Gardening with L’A.I.S (Arduino Irrigation System)

Have you ever dreamt of having a lush, beautiful garden at home year-round? The biggest challenge for plant lovers isn't just watering, but watering "at the right time and in the correct environment."

The L’A.I.S project, or Arduino Irrigation System, is specifically designed to solve this problem. This system is not just a simple timed watering system; it's an intelligent control system that waters your plants only when temperature and time conditions align. From a botanical perspective, watering when the temperature is too high can cause plants to experience "Heat Stress" or make them more susceptible to fungal growth. This system acts as a professional assistant to care for your garden.

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Concept and Structural Design (Design & Fabrication)

We divided the project's development into two main parts to facilitate maintenance and ensure stable operation:

1. The Processing Unit (The Brain)

The core, or "brain," of the system was meticulously crafted with design done through AutoCAD Mechanical, focusing on structural strength and engineering aesthetics. We chose 6mm thick Plywood, cut with a Laser Cutter, and utilized Dovetail joinery. This advanced woodworking technique provides the box with exceptional mechanical strength, even when secured only with Vinavil glue. This box houses the Arduino board, sensors, and all electrical circuitry neatly inside.

2. The Irrigation Part

The main structure for water delivery is made from Laminated timber, precisely cut with a Coping saw. For this section, we opted for screw fastening instead of glue, allowing for easy adjustment or disassembly in the future. A key feature is the design's slanted height, which utilizes gravity to assist in delivering water from the reservoir down to the plant pots, reducing the electrical system's workload.

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In-depth Look at Components and Technical Operation

The L’A.I.S system operates by coordinating data from multiple sensors to decide when to open and close the water valve:

Temperature Sensor System

We installed a temperature sensor to act as a "Safety Logic." The system will not allow watering if the ambient temperature exceeds a set threshold, because watering in extremely hot weather can cause water to evaporate too quickly and potentially lead to heat stress for the plant roots. Users can set this temperature limit according to the type of plants being grown.

Real Time Clock System (Real Time Clock - DS3231)

To ensure the system waters on time even during a power outage, we opted for the DS3231 module, a highly accurate RTC with built-in temperature compensation, preventing time drift. The system constantly checks if the current "hour" and "minute" match the values set by the user.

User Interface (Human Machine Interface - Keypad & LCD)

We designed the system to allow for on-the-fly adjustment of values without reprogramming:

• Keypad: Used for inputting commands, with the following logic:
  • Press "1" to set the desired watering hour.
  • Press "4" to set the desired watering minute.
  • Press "7" to set the Temperature Limit.
• LCD Monitor: A 2-line display showing all current statuses:
  • First line: Displays set time (Sh) and current time (Ch).
  • Second line: Displays temperature limit (Tl) and current temperature (Tm).
  • Note: A Potentiometer is installed on the side to adjust the screen's contrast for optimal visibility in varying light conditions.

Flow Control System (Solenoid Valve & Relay)

Instead of using a water pump, which consumes a lot of power and is noisy, we opted for a Solenoid Valve, which acts as a water gate. This valve works in conjunction with a Relay that receives commands from the Arduino. When the condition "time matches + temperature not exceeded" is true, the Arduino sends a Digital HIGH signal to the Relay to actuate the Solenoid Valve, allowing water to flow from the reservoir to the plants via gravity.

Code Logic Overview

1. The system reads the current time from the DS3231 and temperature from the sensor.
2. Checks conditions: If (current time == set time) AND (current temperature < set limit)
3. If the conditions are true, it commands the Relay to actuate and open the Solenoid Valve.
4. If any of the conditions are false, the valve remains closed to conserve water and ensure system safety.

L’A.I.S is a clear example of applying Embedded Systems in daily life, enabling technology to care for nature sustainably and intelligently.