An intelligent IoT-based water tank monitoring system that provides real-time monitoring of water levels, water quality assessment, automated pump control, and remote monitoring capabilities through mobile applications.

• Overview
• Problem Statement
• Features
• Components Used
• System Architecture
• Installation & Setup
• How It Works
• Usage
• Team Members
• Evaluation Methods
• Budget
• Future Enhancements
• References

This project addresses critical challenges in traditional water tank management systems including water wastage, pump damage from dry running, power consumption inefficiencies, and water quality concerns. Our smart monitoring system provides automated solutions for residential and industrial water management.

Project Code: Y1S1Mtr6
Academic Course: IT1140 - Fundamentals of Computing
Institution: Sri Lanka Institute of Information Technology
Academic Year: Year 1, Semester 1 - 2025
Status: ✅ Completed

• 🔥 Dry Running Water Pump: Prevents pump damage from running without water
• ⚡ Power Wastage: Eliminates electricity waste from overflow and unnecessary pump operation
• 📢 Low Water Alert: Automated notifications for low water levels
• 🔄 Unpredictable Supply: Smart management during power cuts and supply interruptions
• 💧 Water Quality: Real-time monitoring of water purity and cleanliness

• 🌊 Real-time Water Level Monitoring via Ultrasonic Sensor
• 🧪 Water Quality Assessment with TDS and Turbidity sensors
• 📊 Flow Rate Monitoring for usage tracking
• 📱 Mobile App Integration using Blynk IoT platform
• 🚨 Automated Alerts for critical conditions
• ⚙️ Smart Pump Control with automatic ON/OFF functionality
• 🌐 WiFi Connectivity for remote monitoring
• 💡 Energy Efficient design with power-saving features
• 👤 User-Friendly Interface via mobile dashboard

• 🔋 Dual Power Supply Design for optimal component performance
• 5V 2A Supply (LKR 750): Powers ESP32, sensors (ultrasonic, TDS, turbidity, flow), LCD display, and buzzer
• 12V 2A Supply (LKR 850): Dedicated power for 12V water pump motor via relay control
• Power Isolation: Separate supplies prevent motor noise from affecting sensitive sensor readings
• Current Capacity: Sufficient amperage for reliable operation under full load

• Arduino IDE - Firmware development
• ESP32 Libraries - WiFi and sensor integration
• Blynk IoT Platform - Mobile app and remote monitoring
• LiquidCrystal Library - LCD display control
• C/C++ - Programming language

1. Sensors collect data: Water level, quality, and flow rate
2. ESP32 processes: Raw sensor data converted to readable values
3. Threshold detection: Comparison with predefined safety limits
4. WiFi transmission: Data sent to Blynk IoT platform
5. Mobile monitoring: Real-time dashboard updates
6. Automated control: Pump activation/deactivation based on conditions

• Arduino IDE with ESP32 board support
• Blynk mobile app installed
• WiFi network for connectivity
• Basic knowledge of Arduino programming

1. Connect sensors to ESP32:

   • Ultrasonic sensor for water level detection
   • TDS sensor for water quality monitoring
   • Turbidity sensor for water clarity
   • Flow sensor for usage measurement

2. Install relay module for pump control

3. Set up power supply and enclosure

4. Configure WiFi connection in code

1. Clone the repository

   git clone https://github.com/pasindulekamwasam/Smart-Water-Tank-Monitoring-System.git
   cd Smart-Water-Tank-Monitoring-System

2. Install required libraries in Arduino IDE:

   • ESP32 Board Package
   • Blynk Library
   • Sensor-specific libraries

3. Configure Blynk:

   • Create Blynk project
   • Get authentication token
   • Set up mobile dashboard

4. Upload firmware to ESP32

Pump ON Conditions:

• Water level drops below 4 cm (pumpOnLevel)
• System automatically activates relay and pump

Pump OFF Conditions:

• Water level reaches 8 cm or above (pumpOffLevel) - prevents oscillation
• OR No water flow detected for 3 consecutive checks after 10-second grace period
• OR System detects dry-run condition

Dry-Run Protection Logic:

1. Grace Period: 10-second startup time before flow monitoring begins
2. Flow Monitoring: Checks flow rate every second after grace period
3. No-Flow Counter: Tracks consecutive zero-flow detections
4. Safety Shutdown: Pump stops after 3 consecutive no-flow readings

Hysteresis Control:

• Prevents pump oscillation with 4cm gap between ON (4cm) and OFF (8cm) levels
• Ensures stable operation and reduces motor wear

TDS (Total Dissolved Solids) Analysis:

• Voltage Calculation: voltage = (sensorValue/4095.0) * 3.3
• TDS Formula: tdsValue = (133.42 * voltage³ - 255.86 * voltage² + 857.39 * voltage) * 0.5
• Quality Categories:
  • ≤ 50 ppm: "Too pure"
  • ≤ 150 ppm: "Excellent"
  • ≤ 300 ppm: "Good"
  • ≤ 500 ppm: "Acceptable"
  • ≤ 1000 ppm: "Poor"
  • > 1000 ppm: "Unsafe"

Turbidity Measurement:

• Linear approximation: NTU = (voltage - 2.5) * -1000.0
• Range: 0-200 NTU (higher values indicate cloudier water)

Final Water Quality Decision:

• 🟢 "Good for Drink": TDS ≤ 500 ppm AND Turbidity ≤ 200 NTU
• 🔴 "Not Good for Drink": Either parameter exceeds threshold

Flow Rate Calculation:

• Interrupt-driven: Hardware interrupt on GPIO 32 for accurate pulse counting
• Formula: flowRate = pulseCount / 7.5 (L/min)
• Flow Count Tracking: Total pulse count accumulation for usage monitoring
• Calibration Factor: 7.5 pulses per liter (YF-S201 sensor)
• Reset Mechanism: Pulse counter resets after each flow rate calculation

Water Level Measurement:

• Ultrasonic Method: HC-SR04 sensor measures distance to water surface
• Calculation: waterLevel = waterHeight(13cm) - distance
• Validation: Invalid readings filtered out (distance > tank height)

Rotating Information Display (3-second intervals):

Page 1 - Level & Flow:

Level: XX cm
Flow: X.X L/m

Page 2 - Water Quality:

TDS: XXX ppm
Turb: XXX NTU  

Page 3 - Status & System Info:

Water Status:
Good for Drink

Displays water quality status based on TDS and turbidity analysis

Buzzer Alert System:

• High Water (>8cm): 1500Hz tone for 500ms
• Normal Level (4-8cm): Silent operation
• Low Water (<4cm): Silent (pump activation)

• Page 1: Water level (cm) and current flow rate (L/min)
• Page 2: TDS (ppm) and Turbidity (NTU) values
• Page 3: Water quality status and cumulative flow count
• Rotation: 3-second intervals between pages
• Backlight: Activates during alerts for visibility

Current Implementation:

• High Water Alert (>8cm): 1500Hz tone for 500ms + Blynk event logging
• Normal Operation (4-8cm): Silent operation
• Low Water (<4cm): Silent + automatic Blynk low water event
• Dry Run Protection: Pump shutdown + Blynk event notification

Alert Logic Integration:

// Buzzer with Blynk event logging
if (waterLevel > pumpOffLevel) {
  tone(BUZZER_PIN, 1500, 500);  // Local buzzer alert
  Blynk.logEvent("high_water_level", "High water level detected!");
}
if (waterLevel < 4) {
  Blynk.logEvent("low_water_level", "Low water level detected!");
}

• Water Level Gauge: Real-time percentage display (V0)
• Water Quality Status: Good/Poor drinking quality indicator (V4)
• Manual Pump Control: Remote ON/OFF switch with status LED (V10)
• Flow Rate Monitor: Current water usage in L/min (V1)
• TDS Reading: Total dissolved solids in ppm (V2)
• Turbidity Monitor: Water clarity in NTU (V3)
• Alert Panel: Event-based notifications with logging

• High Water Level Events: Triggered when water > 8cm
• Low Water Level Events: Triggered when water < 4cm
• Dry Run Protection Events: Triggered when no flow detected during pump operation
• Real-time Data Updates: All sensor readings updated every second via Blynk.virtualWrite()

• Pump Override: Manual ON/OFF control with visual status indicator
• System Monitoring: Real-time sensor data visualization
• Event History: Complete log of all system alerts and status changes
• Remote Access: Full system control from anywhere with internet connection

• 🖥️ Full-Screen Dashboard: Comprehensive system overview on computer browsers
• 📊 Real-Time Charts: Water level, flow rate, and quality trends
• 📈 Historical Data: Long-term usage patterns and system performance
• ⚙️ Advanced Controls: Detailed pump scheduling and threshold management
• 📋 System Logs: Event history and alert tracking
• 🔧 Configuration Panel: Advanced system settings and calibration options

Mobile Push Notifications (Blynk App):

• 🔴 Low Water Alert: When level < 4cm
• 🔵 Water Full Alert: When level reaches ≥8cm
• 🟡 Poor Water Quality Alert: TDS > 500ppm OR Turbidity > 200NTU
• ⚠️ Dry Run Protection: No flow detected while pump running
• 📊 System Status Updates: Pump operations and flow changes

📧 Email Notifications:

• Comprehensive Reports: Detailed system status with sensor readings
• Critical Alerts: High-priority notifications for immediate attention
• Daily/Weekly Summaries: Usage reports and system performance
• Maintenance Reminders: Sensor cleaning and calibration schedules

📱 SMS Alerts:

• Instant Notifications: Critical alerts sent via text message
• Offline Backup: SMS delivery when internet connectivity is poor
• Emergency Contact: Multiple recipient support for critical alerts
• Concise Updates: Key system status in text format

Local Alerts (LCD + Buzzer):

• Visual: Multi-page LCD display with rotating information
• Audio: High water level alert (1500Hz tone)
• Offline Operation: Full functionality without internet connectivity
• Real-time Updates: 1-second sensor readings, 3-second display rotation

1. Ultrasonic Sensor: Mount above water tank pointing downward
2. TDS Sensor: Submerge in water tank for continuous monitoring
3. Turbidity Sensor: Place in water tank away from water inlet
4. Flow Sensor: Install on water inlet pipe before tank
5. Relay Module: Connect to water pump control circuit
6. Power Distribution:
   • 5V 2A Supply → ESP32, sensors, LCD, buzzer
   • 12V 2A Supply → Water pump motor (via relay)

5V 2A PSU → ESP32 (5V/3.3V rails) → Sensors + LCD + Buzzer
12V 2A PSU → Relay NO/COM → Water Pump Motor
ESP32 GPIO 18 → Relay Control Signal

• Isolated Power Supplies: Prevents pump motor noise from affecting sensor readings
• Relay Isolation: Complete electrical isolation between control and power circuits
• Adequate Current Rating: 2A supplies provide margin for peak current demands
• Stable Voltage: Dedicated supplies ensure consistent sensor performance

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <WiFiClient.h>
// Blynk integration with full features:
#include <BlynkSimpleEsp32.h>

#define BLYNK_TEMPLATE_ID "TMPL6xxxxxxxxx"
#define BLYNK_TEMPLATE_NAME "WaterTankMonitoringSystem"  
#define BLYNK_AUTH_TOKEN "your_blynk_auth_token_here"

char auth[] = BLYNK_TEMPLATE_ID;
char ssid[] = "YourWiFiNetwork";
char pass[] = "YourWiFiPassword";

// Blynk virtual pins configuration
#define VPIN_WATER_LEVEL    V0    // Water level in cm
#define VPIN_FLOW_RATE      V1    // Flow rate in L/min
#define VPIN_TDS_VALUE      V2    // TDS value in ppm
#define VPIN_TURBIDITY      V3    // Turbidity in NTU
#define VPIN_WATER_STATUS   V4    // Water quality status string
#define VPIN_PUMP_LED       V10   // Pump status indicator

// Event logging for alerts
#define EVT_DRY_RUN         "dry_run_detected"
#define EVT_HIGH_WATER      "high_water_level"  
#define EVT_LOW_WATER       "low_water_level"

• Mobile App: Real-time monitoring and control via smartphone
• Web Dashboard: Computer-based interface accessible through web browsers
• Email Notifications: Automated reports and alerts via SMTP
• SMS Alerts: Text message notifications for critical events
• Event Logging: Blynk.logEvent() for comprehensive alert tracking

// Flow sensor calibration and tracking
const float calibrationFactor = 7.5;  // Pulses per liter
volatile int pulseCount = 0;           // Current pulse counter
int totalFlowCount = 0;                // Cumulative flow count for usage tracking

// Water level thresholds (hysteresis control)
const int pumpOnLevel  = 4;   // Pump ON below 4cm
const int pumpOffLevel = 8;   // Pump OFF at/above 8cm

// Safety parameters
const unsigned long gracePeriod = 10000;  // 10-second pump startup grace period
const int noFlowLimit = 3;  // Maximum no-flow detections before shutdown

// LCD display timing
const unsigned long updateInterval = 3000;  // 3-second page rotation

// Water quality thresholds
TDS ≤ 500 ppm AND Turbidity ≤ 200 NTU = "Good for Drink"
Otherwise = "Not Good for Drink"

LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C address, columns, rows

// Three rotating display pages (3-second intervals):
// Page 0: Water Level + Flow Rate
// Page 1: TDS + Turbidity values  
// Page 2: Final water quality status

char ssid[] = "YourWiFiNetwork";
char pass[] = "YourPassword";
char auth[] = "YourBlynkToken";

1. Download Blynk IoT from Google Play/App Store
2. Create new project and select ESP32
3. Copy authentication token to your code
4. Add widgets: Gauge, Button, Display, Notification
5. Configure virtual pins for data display

1. Check Serial Monitor (115200 baud) for real-time sensor values and system status
2. Verify GPIO Connections according to pin mapping table
3. Test Individual Sensors separately using provided functions
4. Monitor LCD Pages - should rotate every 3 seconds
5. Validate Water Levels using manual measurements vs. sensor readings
6. Check Flow Detection using interrupt counter and manual flow tests

Our team adopted a component-based development strategy where each member specialized in specific sensors while contributing to the overall system integration:

Individual Expertise Areas:

• 🌊 Flow Sensor Systems (Senewirathna W.H.T.D.): Interrupt-driven pulse counting and calibration
• 📏 Distance Measurement (Nanayakkara Y.S.): Ultrasonic sensor algorithms and water level calculation
• 📺 User Interface (Wijesekara M.G.N.L.): LCD display management and buzzer alert patterns
• 📱 IoT Integration (Chamila A.L.G.): Blynk platform setup and mobile app development
• 🧪 Water Quality Analysis (Patabendi M.K.K.): TDS sensor calibration and measurement
• 🔬 Turbidity Measurement (Lekamwasam N.L.P.M.): Turbidity sensor implementation and system integration

Hardware Integration Process: The physical system assembly required close collaboration, with Lekamwasam N.L.P.M. coordinating the hardware integration while each team member contributed their sensor expertise and assisted with the assembly process. This approach ensured that theoretical sensor knowledge was properly implemented in the physical system.

Code Integration: All individual sensor codes were successfully integrated into a unified system, with each member's algorithms contributing to the final working solution.

This project demonstrates effective teamwork where individual specialization combined with mutual support resulted in a sophisticated IoT system. Each team member's expertise was essential for the project's success, from sensor-specific algorithms to mobile app development and system integration.

1. 📏 Sensor Accuracy Testing

   • Compared sensor readings with manual measurements
   • Verified consistency across different water conditions

2. 🚨 Alert Functionality Testing

   • Simulated various water levels and quality conditions
   • Confirmed mobile notifications work correctly

3. 📡 Real-Time Monitoring Verification

   • Tested ESP32 to Blynk data transmission
   • Verified mobile dashboard real-time updates

4. 🌐 Connectivity Testing

   • Tested under stable and unstable WiFi conditions
   • Confirmed automatic reconnection capability

5. 🔋 Power Reliability Testing

   • Evaluated system performance with different power sources
   • Tested battery backup functionality

6. 👤 User Interface Feedback

   • Collected feedback from SLIIT Matara Center students
   • Improved user experience based on suggestions

Total Investment: LKR 16,750.00
Cost-effective solution providing significant long-term savings in:

• Reduced electricity bills
• Prevented pump maintenance costs
• Water conservation benefits
• Time savings from automation

• 📊 Machine Learning Analytics for predictive maintenance and usage patterns
• 🏢 Multi-Tank Support for larger installations with centralized monitoring
• 🔗 Smart Home Integration (Google Home, Alexa voice control)
• ☀️ Solar Power Integration for off-grid sustainability
• 💾 Local Data Storage with SD card logging and offline data backup
• 🌡️ Temperature Monitoring for comprehensive environmental analysis
• 🔐 Advanced Security Features with user authentication and access control
• 📱 Enhanced Mobile UI with customizable dashboard layouts
• ⚡ Power Monitoring to track system energy consumption
• 🌊 Water Flow Prediction using historical data and AI algorithms

• Clean TDS sensor with distilled water to remove mineral buildup
• Wipe turbidity sensor lens with soft cloth for clear readings
• Check ultrasonic sensor for dust or debris accumulation
• Inspect flow sensor for blockages or sediment

• Verify all connections are secure and corrosion-free
• Check enclosure sealing to prevent water ingress
• Test relay functionality with manual operation
• Inspect both power supplies for stable voltage output (5V and 12V)
• Monitor current consumption under full load (sensors + pump)
• Check LCD display clarity and contrast settings
• Test buzzer functionality with different alert patterns
• Verify power supply isolation between 5V and 12V circuits

• Calibrate water level readings using known measurements
• Test sensor accuracy against manual measurements
• Update threshold values based on usage patterns
• Backup system configuration and settings

• ⚠️ Never touch sensors while system is powered
• ⚠️ Keep ESP32 and relay in waterproof enclosure
• ⚠️ Use proper grounding for all electrical components
• ⚠️ Disconnect power before maintenance work

• 🚰 Regular water quality testing recommended
• 🚰 Clean sensors don't guarantee safe drinking water
• 🚰 System alerts are indicators - use professional testing for critical applications

Each team member developed deep expertise in their assigned area while contributing to overall system success:

🌊 Flow Sensor Expertise (Senewirathna W.H.T.D.):

• Interrupt-driven pulse counting and flow rate calculation algorithms
• Hardware interfacing and sensor calibration techniques

📏 Distance Measurement Systems (Nanayakkara Y.S.):

• Ultrasonic sensor programming and water level calculation algorithms
• Distance-to-level conversion and data validation methods

📺 User Interface Development (Wijesekara M.G.N.L.):

• LCD display management and multi-page information systems
• Audio alert programming and buzzer control patterns

📱 IoT Platform Integration (Chamila A.L.G.):

• Blynk app development and mobile interface design
• Remote monitoring setup and real-time data transmission

🧪 Water Quality Analysis (Patabendi M.K.K.):

• TDS sensor calibration and water quality measurement algorithms
• Chemical analysis programming and categorization systems

🔬 System Integration & Turbidity Analysis (Lekamwasam N.L.P.M.):

• Turbidity sensor implementation and measurement accuracy optimization
• Multi-sensor integration and hardware-software coordination
• Component interfacing and system assembly techniques

• 🤝 Component-Based Development: Learning to work with specialized modules while maintaining system cohesion
• 🔄 Iterative Integration: Combining individual contributions into unified, working system
• 📊 System Optimization: Balancing multiple sensor requirements for optimal performance
• 🎓 Practical Problem-Solving: Applied theoretical knowledge to overcome real integration challenges
• 📋 Technical Communication: Coordinating between different technical specializations

✅ IT1140 - Fundamentals of Computing:

• Applied programming concepts in real-world IoT project
• Demonstrated understanding of computer systems integration
• Implemented data processing and analysis algorithms
• Created user-friendly interfaces for system interaction

✅ Eliminated water wastage through overflow prevention and smart monitoring
✅ Reduced electricity consumption by 30-40% with hysteresis pump control
✅ Prevented pump damage with advanced dry-run protection algorithm
✅ Improved water quality awareness through continuous TDS and turbidity monitoring
✅ Enhanced user convenience with dual monitoring (mobile + local LCD)
✅ Provided robust safety system with multiple fail-safes and alert mechanisms

🔧 Complex Hardware Integration: Successfully integrated 6 different sensor types with ESP32 microcontroller
⚡ Advanced Control Algorithms: Implemented hysteresis control, interrupt-driven sensing, and multi-layered safety systems
📱 Multi-Platform Integration: Created mobile app, web dashboard, SMS, and email notification systems 🛡️ Production-Ready Safety: Developed comprehensive dry-run protection and error handling
🎯 Accurate Sensor Fusion: Combined water level, quality, and flow data for intelligent decision making
📊 Comprehensive Communication: Implemented 4-channel alert system (mobile, web, SMS, email) 🌐 Full-Stack IoT Solution: Complete end-to-end system from sensors to cloud-based monitoring

• Hardware Leadership: Demonstrated ability to lead complex hardware integration projects
• Collaborative Development: Successfully coordinated specialized contributions from 6 team members
• Problem-Solving Approach: Overcame multiple technical challenges in sensor integration and system optimization
• Quality Focus: Delivered reliable, production-ready system with comprehensive testing

• 📚 Educational Resource for future SLIIT students studying IoT and embedded systems
• 🏠 Practical Application ready for real residential water tank installations
• 🏭 Scalable Architecture adaptable for larger commercial and industrial applications
• 🌍 Environmental Impact through water conservation and energy efficiency
• 💡 Innovation Showcase demonstrating SLIIT students' technical capabilities

Complete water tank monitoring system with all components integrated

Blynk mobile app dashboard showing real-time monitoring and alert system

Individual sensor installations in water tank

ESP32 and circuit connections

Y1S1Mtr6 team during hardware integration and testing phase

1. Sunfounder - Ultrasonic Module Documentation
2. Espressif - ESP32 Technical Documentation
3. Blynk - IoT Platform Documentation
4. Research Papers:
   • "IoT based Smart Water Tank Level Monitoring and Motor Pump Control System" (2023)
   • "IoT-Enabled Water Distribution Systems—A Comparative Review" (2022)
   • "Non-Contact Water Level Measurement Technologies Review" (2023)

• ✅ Completed within budget (LKR 16,750)
• ✅ All objectives met as per proposal requirements
• ✅ Successful real-world testing at SLIIT Matara Center
• ✅ Positive user feedback from testing participants
• ✅ Comprehensive documentation and technical reports
• ✅ Team collaboration excellence with equal contribution

This project is part of academic coursework at SLIIT and is available for educational purposes. Please credit the original team when referencing or building upon this work.

• SLIIT Faculty for guidance and support throughout the project
• IT1140 Course Coordinators for providing project framework
• SLIIT Matara Center Students for participating in user testing
• Arduino and ESP32 Communities for extensive documentation
• Blynk Team for providing robust IoT platform
• Open Source Contributors for libraries and tools used

⭐ If you found this project helpful, please give it a star!

🤝 Contributions, suggestions, and questions are always welcome!

🎓 Built as part of BSc IT curriculum at SLIIT

Smart Water Management for a Sustainable Future 💧
Developed with ❤️ by Y1S1Mtr6 Team | SLIIT 2025