Water Level Measurement

🔗 Wiring Connections

Component Pin	Arduino Pin	Purpose
VCC	5V	Provides power to the ultrasonic sensor.
GND	GND	Completes the electrical connection.
TRIG	Digital Pin 9	Sends the ultrasonic pulse to measure distance.
ECHO	Digital Pin 10	Receives the returning signal from the sensor.

⚡ Circuit Overview

The ultrasonic sensor works like the eyes of your water level system. It sends out sound waves and measures how long they take to bounce back from the water surface. The Arduino Uno reads this information and uses it to calculate how full the bottle is.

The sensor needs power from the Arduino's 5V and GND pins. The TRIG and ECHO pins are connected to digital pins so the Arduino can send signals and receive measurements.

💡 Hardware Tips

• Make sure VCC and GND are connected correctly before powering your Arduino.
• Keep jumper wires firmly connected to avoid incorrect sensor readings.
• Place the ultrasonic sensor straight above the water surface for accurate measurements.
• Make clear percentage markings on the bottle so you can compare readings easily.
• Test the sensor using the Serial Monitor before attaching the final bottle setup.

🔌 Circuit Diagram

💻 Complete Arduino Code

Now it is time to program your water level measurement system! This Arduino code reads the ultrasonic sensor, checks the distance to the water, and shows the fill level on the Serial Monitor.

const int trigPin = 9;
const int echoPin = 10;

// ===== SET YOUR DISTANCES (in cm) =====
float level_100 = 4.0;   // FULL
float level_75  = 8.0;
float level_50  = 12.0;
float level_25  = 16.0;  // LOW

// Number of samples for averaging (for stability)
const int samples = 5;

long duration;
float distance;

// Function to get averaged distance
float getDistance() {
  float sum = 0;

  for (int i = 0; i < samples; i++) {
    // Trigger pulse
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);

    // Read echo
    duration = pulseIn(echoPin, HIGH, 30000); // timeout 30ms

    // Convert to distance
    float d = duration * 0.034 / 2;

    sum += d;
    delay(50);
  }

  return sum / samples;
}

void setup() {
  Serial.begin(9600);
  
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  Serial.println("Water Level Monitoring System");
  Serial.println("-----------------------------");
}

void loop() {
  distance = getDistance();

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // ===== WATER LEVEL LOGIC =====
  if (distance <= level_100) {
    Serial.println("Water Level: 100% (FULL)");
  } 
  else if (distance <= level_75) {
    Serial.println("Water Level: 75%");
  } 
  else if (distance <= level_50) {
    Serial.println("Water Level: 50%");
  } 
  else if (distance <= level_25) {
    Serial.println("Water Level: 25%");
  } 
  else if (distance > level_25 && distance < 400) {
    Serial.println("Water Level: BELOW 25% / EMPTY");
  } 
  else {
    Serial.println("Sensor Error / Out of Range");
  }

  Serial.println("-----------------------------");
  delay(1000);
}

🧠 Code Explained

Variables

Variables store values that the Arduino uses while running the project. The trigPin and echoPin variables tell the Arduino where the ultrasonic sensor is connected. The level values store the distance ranges for different water percentages.

setup()

The setup() function runs once when the Arduino starts. It sets the sensor pins as input and output, starts the Serial Monitor, and displays the project name.

loop()

The loop() function runs continuously. It measures the water distance, checks which level range it matches, and prints the result on the Serial Monitor.

Calculations / Helper Functions

The getDistance() function takes multiple sensor readings and calculates an average. This makes the readings more stable and reduces small measurement errors.

📚 Key Concepts

• Variables store information like sensor values and settings.
• Functions help organize code into reusable blocks.
• Loops repeat instructions so the Arduino can keep monitoring water levels.
• if statements help the Arduino make decisions based on sensor readings.
• pulseIn() measures the time taken for the ultrasonic signal to return.
• The Serial Monitor displays live data from your Arduino.

🎉 Great Job!

Awesome work! 🎊 You've built a smart Arduino water level measurement system using an ultrasonic sensor. Your project can detect how full a container is and display the result in real time using the Serial Monitor.

🧠 What You Learned

• How an ultrasonic sensor measures distance.
• How to connect sensors to an Arduino Uno.
• How Arduino uses sensor data to make decisions.
• How to display live readings using the Serial Monitor.
• How robotics and electronics can solve real-world problems.

🏆 Next Challenges

1. Easy: Add LEDs to show whether the bottle is Full, Half Full, or Low.
2. Medium: Add a buzzer that sounds when the water level drops below 25%.
3. Advanced: Upgrade the project with an OLED display or ESP32 to monitor water levels wirelessly.

📤 Submit Your Project

Ready to show off your project? Follow these simple steps:

1. Record a short video demonstrating your project.
2. Show the bottle at different water levels and the percentage changing on the Serial Monitor.
3. Upload the video to YouTube as Public or Unlisted.
4. Copy the YouTube link and paste it into the submission form below.

[Submission Form Placeholder]

🔒 Note: Students must be signed in before submitting their project.