#define ECHO_PIN 7
#define TRIG_PIN 8

#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,20,4);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  lcd.init();
  lcd.backlight();
}

float readDistanceKM()
{
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2;
}

void loop() {
  // put your main code here, to run repeatedly:
  float distance = readDistanceKM();
  Serial.print("Measured distance : ");
  Serial.println(distance);
  lcd.setCursor(0,0);
  lcd.print("Dist:");
  lcd.println(distance);
  delay(1000);
}