[Arduino] Ultrasonic Sensor Water Level Detector + Code

[protaa]

Overview:

This project uses an ultrasonic sensor (HC-SR04) to measure the water level in a tank. The measured distance is used to calculate the water level, which is then displayed via Serial Monitor or LCD (optional). It's useful for automating tank refills or monitoring water levels in remote locations.

Requirements:

• Arduino Uno (or any compatible board)

• HC-SR04 Ultrasonic Sensor

• Breadboard and jumper wires

• USB Cable for Arduino

• (Optional) 16x2 LCD with I2C module

• (Optional) Buzzer or LED for low water alert

• Power supply (e.g., USB or battery)

 

Wiring / Circuit Diagram:

Basic Connections (without LCD):

 

HC-SR04 Pin	Arduino Pin
VCC	5V
GND	GND
TRIG	D9
ECHO	D10

  

Source Code:

#define trigPin 9
#define echoPin 10

long duration;
float distance;
float tankHeight = 30.0;  // in cm — adjust to match your tank height

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

void loop() {
  // Send ultrasonic pulse
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Read echo time
  duration = pulseIn(echoPin, HIGH);

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

  // Calculate water level
  float waterLevel = tankHeight - distance;
  if (waterLevel < 0) waterLevel = 0;

  Serial.print("Water Level: ");
  Serial.print(waterLevel);
  Serial.println(" cm");

  delay(1000);
}