#include <LiquidCrystal_I2C.h>

const int trigPin = 9;
const int echoPin = 10;
const int relay1 = 11;
const int relay2 = 12;
const int ledPin = 8;

LiquidCrystal_I2C lcd(0x27, 16, 2);

long duration;
long distance;
long safetyDistance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(relay1, OUTPUT);
  pinMode(relay2, OUTPUT);

  lcd.begin(16, 2);
  lcd.setCursor(0, 0);
  lcd.print("Place your hand");

}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);

  distance = duration*0.034/2;

  safetyDistance = distance;
  if(safetyDistance <= 30){
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Disinfecting");
    digitalWrite(relay1, HIGH);
    digitalWrite(relay2, HIGH);
    digitalWrite(ledPin, HIGH);
    delay(1000);
    digitalWrite(ledPin, LOW);
  }
  else{
    digitalWrite(relay1, LOW);
    digitalWrite(relay2, LOW);
    digitalWrite(ledPin, LOW);
    lcd.setCursor(0, 0);
    lcd.print("Place your hand");
  }
}