📏 Distance Measure

Measure the distance of nearby objects using the HC-SR04 ultrasonic sensor.

Components Needed

Arduino UNO

HC-SR04 Ultrasonic Sensor

Breadboard

Jumper Wires

  • How It Works

    The HC-SR04 sensor sends an ultrasonic pulse and measures the time it takes for the echo to return. The Arduino calculates the distance and displays it in the Serial Monitor.

  • What You'll Learn

    ✅ Ultrasonic sensing

    ✅ Distance measurement

    ✅ Reading sensor data

    ✅ Serial Monitor basics

  • Code

    #define TRIG_PIN 9
    #define ECHO_PIN 10

    void setup() {
    Serial.begin(9600);
    pinMode(TRIG_PIN, OUTPUT);
    pinMode(ECHO_PIN, INPUT);
    }

    void loop() {
    digitalWrite(TRIG_PIN, LOW);
    delayMicroseconds(2);

    digitalWrite(TRIG_PIN, HIGH);
    delayMicroseconds(10);

    digitalWrite(TRIG_PIN, LOW);

    long duration = pulseIn(ECHO_PIN, HIGH);

    float distance = duration * 0.034 / 2;

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

    delay(500);
    }
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