Distance Calculator

Circuit Schematic:

Code:

// Distance Calculator (ultrasonic version)

// By, Umar Rao

// Circuit available on http://www.arduinocoder.blogspot.com

/*

Components Required:

(1) Liquid Crystal Display

(2) Ultrasonic Sensor (HC-SR04)

(3) 1 220 ohm resistor

(4) 1 potentiometer

*/

#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

const int trigPin = 7;

const int echoPin = 8;

void setup() { 

  lcd.begin(16, 2);   

}

void loop() { 

  long duration, cm;

  pinMode(trigPin, OUTPUT);

  digitalWrite(trigPin, LOW);

  delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);

  delayMicroseconds(10);

  digitalWrite(trigPin, LOW);

  

  pinMode(echoPin, INPUT);

  duration = pulseIn(echoPin, HIGH);

  cm = microsecondsToCentimeters(duration);

  

  lcd.print("Distance (cm):");

  lcd.setCursor(0, 1);

  lcd.print(cm);

  delay(100);

  lcd.clear(); 

}

long microsecondsToCentimeters(long microseconds){

  return microseconds / 29  / 2;

}