Ultrasonic Distance Tracker

Ultrasonic Distance Tracker

Image: SparkFun HC-SR04 Ultrasonic-Sensor 13959-01a.jpg by SparkFun via Wikimedia Commons, CC BY 2.0

How It Works

• The ultrasonic sensor (HC-SR04) emits a short ultrasonic pulse and starts a timer.
• The pulse reflects off the nearest object and returns to the sensor's receiver, stopping the timer.
• The Arduino calculates distance from the round-trip time and the speed of sound, then displays the result on an LCD.
• Configurable near/far thresholds can trigger a buzzer warning as an object gets too close, useful for parking-assist style use.

Components

Arduino Uno
Ultrasonic sensor (HC-SR04)
16x2 LCD display
Buzzer (proximity warning)
Enclosure/mount

Applications

• Home or garage parking assistance
• General obstacle detection for robotics projects
• Standalone distance-measuring tool

Advantages

• Accurate, real-time distance readings on inexpensive hardware
• Simple to adapt into other projects needing proximity sensing
• Configurable warning threshold suits different use cases

Sample Code — Distance Measurement and LCD Display

// Simplified ultrasonic distance tracker - Arduino
#include 
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
#define TRIG 9
#define ECHO 10

long readDistanceCM() {
  digitalWrite(TRIG, LOW); delayMicroseconds(2);
  digitalWrite(TRIG, HIGH); delayMicroseconds(10);
  digitalWrite(TRIG, LOW);
  long duration = pulseIn(ECHO, HIGH);
  return duration * 0.034 / 2;
}

void setup() {
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  lcd.begin(16, 2);
}

void loop() {
  long dist = readDistanceCM();
  lcd.setCursor(0, 0);
  lcd.print("Distance: ");
  lcd.print(dist);
  lcd.print(" cm ");
  delay(300);
}

Related Research

• Car Parking Distance Controller Using Ultrasonic Sensors Based On Arduino Uno — ResearchGate