Course Content

1. Introduction

Water leakage is a serious issue that can lead to extensive property damage, mold growth, short circuits, and high water bills if not detected early. In many homes, offices, and industries, leaks go unnoticed until the damage becomes visible, often too late for preventive action.

To address this, we propose a smart water leakage detection system using a Raspberry Pi Zero, a compact and cost-effective microcontroller. This system continuously monitors water-sensitive areas using sensors and provides real-time alerts using visual, audible, and IoT-based mechanisms. It is suitable for locations like under sinks, near tanks, around pipelines, or in server rooms.

The Raspberry Pi Zero's built-in computing power and GPIO interface make it ideal for handling sensors, actuators, and communication modules while keeping the design compact and energy-efficient.

2. Working Principle

The system works on the conductivity principle using a water leak sensor, which detects the presence of water by measuring the resistance between its terminals. In dry conditions, the resistance is high (no conduction), and when water is present, the resistance drops, completing a circuit.

Here's how it functions:

• When water comes into contact with the sensor terminals, it conducts electricity.

• This signal is read by the Raspberry Pi Zero via a GPIO pin.

• Based on this input, the Raspberry Pi executes a pre-programmed script to:

  • Activate a buzzer or LED for immediate local alert.

  • Display a warning message on an LCD.

  • Optionally, send notifications through cloud services or mobile apps (via Wi-Fi).

This setup helps detect leaks at an early stage and alert the user instantly to take corrective action.

3. Methodology

The step-by-step working of the system is as follows:

🔸 Step 1: Sensor Monitoring

• The Raspberry Pi continuously checks the output from the water leak sensor through its GPIO pins.

🔸 Step 2: Leakage Detection

• If the sensor detects water, it sends a LOW signal to the Pi (or a change in voltage level).

🔸 Step 3: Processing Signal

• The Pi runs a Python script that evaluates the sensor signal and determines whether to trigger an alert.

🔸 Step 4: Alert Mechanism

• Local Alert: Turns ON a buzzer and/or LED.

• Visual Alert: Displays a message like "Water Leak Detected!" on the LCD.

• Remote Alert (optional): Sends a notification to a mobile device via:

  • Email

  • Blynk App

  • Telegram bot

  • IFTTT service

🔸 Step 5: Logging (optional)

• The system can log the timestamp and duration of each leak for later analysis or maintenance records.

4. Components Used