EECS 1012 - Automated Plant Watering System 🌱💧

Author: Crystal Mumtaz-Shah
Course: EECS 1021
Date: April 12, 2024

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Table of Contents

• Introduction
• Project Context
• Features
• Components
• Setup & Installation
• Implementation
• Testing
• Learning Outcomes
• Conclusion

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Introduction

This project is an automated plant watering system that monitors soil moisture levels via voltage readings from a sensor. It activates a water pump when the soil is dry (voltage > 3.4V) and stops when the soil is adequately moist (voltage ≤ 2.8V). The system includes real-time data plotting and an OLED display for status updates.

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Project Context

Maintaining optimal soil moisture is critical for plant health. Manual monitoring is error-prone and time-consuming. This system automates the process by:

• Continuously measuring soil moisture.
• Watering plants when needed.
• Displaying real-time metrics (voltage, moisture level) on an OLED.
• Plotting data on a live graph.

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Features

🌟 Core Functionality

• State Machine: Uses if/else statements to control the pump based on voltage thresholds.
• Real-Time Data Plotting: Graphs moisture vs. time using Princeton's StdDraw library.
• OLED Display: Shows moisture levels, voltage, and pump status.
• Emergency Stop: A button to manually turn off the pump.

📊 Data Management

• ArrayList<Double> moistureList: Tracks moisture values over time.
• HashMap<Integer, Double> voltageMap: Maps timestamps to voltage readings.

🔌 Hardware Integration

• Arduino Communication: Uses Firmata4J to send/receive commands.
• Components: Moisture sensor, MOSFET, 12V battery, water pump.

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Components

Component	Purpose
Arduino Grove Board	Controls all components.
Moisture Sensor (A0)	Measures soil moisture.
Water Pump (D2)	Delivers water to the plant.
MOSFET	Regulates pump conductivity.
12V Battery	Powers the pump.
OLED Display	Shows real-time data.
Laptop (IntelliJ)	Hosts the Java program.

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Setup & Installation

Hardware Setup

1. Connect the moisture sensor to A0.
2. Connect the MOSFET to D2.
3. Power the pump with the 12V battery.
4. Link the Arduino to the laptop via USB.

Software Dependencies

• Java (with Firmata4J library for Arduino communication).
• Princeton Standard Library (StdDraw for graphing).
• Arduino IDE (to upload Firmata firmware).

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Implementation

Code Structure

• Main Class: Manages the state machine, data collection, and Arduino communication.
• Graph Class: Handles real-time plotting using StdDraw.
• Test Class: Validates sensor readings, pump control, and button functionality.

Key Logic Snippets

// State Machine Example
if (voltage > 3.4) {
    pump.on();
    oled.display("Watering...");
} else if (voltage <= 2.8) {
    pump.off();
    oled.display("Soil Moist");
}

// Data Collection
moistureList.add(moistureValue);
voltageMap.put(counter_Array, voltage);

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Testing

A dedicated test class ensures:

1. Board Connection: Confirms Arduino is detected.
2. Sensor Accuracy: Validates moisture-to-voltage conversion.
3. Pump Control: Tests activation/deactivation via voltage thresholds.
4. Emergency Button: Verifies manual override functionality.

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Learning Outcomes

• CLO1: Built a test suite to validate hardware/software integration.
• CLO2: Integrated StdDraw for graphing and Firmata4J for Arduino communication.
• CLO3: Utilized ArrayList and HashMap for efficient data tracking.
• CLO4: Designed a state machine with if/else logic for pump control.
• CLO5: Applied encapsulation (e.g., private variables) for modular code.

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Conclusion

This project demonstrates the effective use of object-oriented programming and hardware integration to solve real-world problems. By combining Arduino, Java, and real-time data visualization, the system ensures optimal plant health with minimal manual intervention. Future enhancements could include IoT integration for remote monitoring!