#include <LiquidCrystal.h>

// Define LCD connections
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

// Define ultrasonic sensor connections
const int trigPin = 7;
const int echoPin = 6;

void setup() {
  // Initialize LCD
  lcd.begin(16, 2);
  
  // Initialize ultrasonic sensor pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  
  // Set up Serial Monitor for debugging
  Serial.begin(9600);
}

void loop() {
  // Variables for the duration of the ping, and the distance result in inches and centimeters
  long duration, inches, cm;
  
  // Clear the trigPin by setting it low
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  
  // Calculating the distance
  inches = duration / 74 / 2;
  cm = duration / 29 / 2;
  
  // Print distance on Serial Monitor
  Serial.print(inches);
  Serial.print("in, ");
  Serial.print(cm);
  Serial.print("cm");
  Serial.println();
  
  // Display distance on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Distance:");
  lcd.setCursor(0, 1);
  lcd.print(cm);
  lcd.print(" cm");
  
  // Delay before next reading
  delay(1000);
}