Introduction

A Water Level Indicator is an electronic system used to monitor the level of water in a tank or reservoir. It provides visual or audio indications when the water reaches certain levels such as low, medium, or full. This system helps in preventing water overflow and wastage.

Water level indicators are commonly used in homes, apartments, industries, and agricultural fields.

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Objective of the Project

The main objectives of this project are:

• To indicate the water level inside a tank.
• To prevent water overflow and water wastage.
• To reduce manual monitoring of water tanks.
• To understand sensor-based level detection systems.

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Working Principle

The working of a water level indicator is based on the conductivity of water.

Basic Method

• Metal probes are placed at different heights inside the water tank.
• When water reaches a probe, it completes the electrical circuit.
• This allows current to flow and turns ON the corresponding LED or buzzer.
• Different LEDs indicate different water levels (Low, Medium, High, Full).

Arduino-Based Method

• Arduino reads the status of probes or water level sensors.
• When water touches a probe, Arduino detects the signal.
• LEDs and buzzer are activated based on the detected water level.

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Components Required

Basic Water Level Indicator

• Metal probes (wires or rods)
• LEDs (Low, Medium, High, Full)
• Resistors (220Ω)
• Transistors (BC547)
• Buzzer (optional)
• Power Supply (5V–12V)
• Breadboard & wires

Arduino-Based Water Level Indicator

• Arduino Uno
• Water level sensor or probes
• LEDs
• Buzzer
• Resistors
• Jumper wires

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Circuit Diagram

Basic Water Level Indicator Circuit

 +Vcc
  |
 [LED + 220Ω]
  |
 [Probe]
  |
 Water Tank
  |
 Common Ground Probe ---- GND

Each probe is connected to a separate LED indicating a specific water level.

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Arduino-Based Circuit

Probe 1 (Low) ---- Arduino D2
Probe 2 (Medium) - Arduino D3
Probe 3 (High) --- Arduino D4
Probe 4 (Full) --- Arduino D5

LEDs ------------ Arduino D8–D11
Buzzer ---------- Arduino D12
GND ------------- Common Probe

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Arduino Code for Water Level Indicator

int lowLevel = 2;
int midLevel = 3;
int highLevel = 4;
int fullLevel = 5;

int ledLow = 8;
int ledMid = 9;
int ledHigh = 10;
int ledFull = 11;
int buzzer = 12;

void setup() {
  pinMode(lowLevel, INPUT);
  pinMode(midLevel, INPUT);
  pinMode(highLevel, INPUT);
  pinMode(fullLevel, INPUT);

  pinMode(ledLow, OUTPUT);
  pinMode(ledMid, OUTPUT);
  pinMode(ledHigh, OUTPUT);
  pinMode(ledFull, OUTPUT);
  pinMode(buzzer, OUTPUT);
}

void loop() {
  digitalWrite(ledLow, digitalRead(lowLevel));
  digitalWrite(ledMid, digitalRead(midLevel));
  digitalWrite(ledHigh, digitalRead(highLevel));

  if (digitalRead(fullLevel) == HIGH) {
    digitalWrite(ledFull, HIGH);
    digitalWrite(buzzer, HIGH);
  } else {
    digitalWrite(ledFull, LOW);
    digitalWrite(buzzer, LOW);
  }
}

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Advantages

• Prevents water overflow
• Saves water and electricity
• Easy to build and maintain
• Low cost
• Reliable operation

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Applications

• Domestic water tanks
• Apartments and societies
• Industrial water storage
• Agricultural irrigation tanks
• Overhead tank monitoring systems

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Conclusion

The Water Level Indicator is a highly practical and useful electronics project that solves a real-world problem of water wastage. It helps users monitor tank levels efficiently and can be easily upgraded with automatic pump control, GSM alerts, or IoT integration.

This project is ideal for students, beginners, and real-life applications.