Ultrasonic Sensor with Arduino Virtual Lab

Instructions

Objective:

Learn how an ultrasonic sensor measures distance to objects using sound waves and displays readings on the Serial Monitor.

Steps to Perform:

Click "Start Simulation" to power up the Arduino circuit
Drag the red target object towards or away from the ultrasonic sensor
Observe the distance measurement displayed on the canvas
When the target is inside the detection zone (green cone), distance is shown
When the target is outside the cone, "No Object Detected" message appears
Check the Serial Monitor for continuous distance readings every second

Key Concepts:

Ultrasonic Sensor (HC-SR04): Measures distance using sound waves (2-400cm range)
Trigger Pin (Pin 10): Sends ultrasonic pulse (10μs HIGH signal)
Echo Pin (Pin 9): Receives reflected pulse and measures time
Distance Calculation: Distance = (Duration × Speed of Sound) / 2
Serial Monitor: Displays real-time distance measurements in centimeters
pulseIn(): Measures the duration of HIGH pulse on Echo pin
Detection Zone: Cone-shaped area (±20°) where sensor can detect objects

Arduino Code - sketch_ultrasonic_sensor.ino

                        /*
  Ultrasonic Distance Sensor
  Measures distance and displays on Serial Monitor
*/

const int trigPin = 10;         // Trigger pin
const int echoPin = 9;          // Echo pin
long duration;
int distance;

void setup() {
  pinMode(trigPin, OUTPUT);     // Trigger as output
  pinMode(echoPin, INPUT);      // Echo as input
  
  Serial.begin(9600);           // Start serial communication
}

void loop() {
  // Clear the trigger pin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  // Send 10us pulse to trigger
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Read echo pin
  duration = pulseIn(echoPin, HIGH);
  
  // Calculate distance (cm)
  distance = duration * 0.034 / 2;
  
  // Print distance to Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  delay(500);  // Wait 500ms before next reading
}
                    