#include <Wire.h>
#include <LiquidCrystal_I2C.h>

#define TRIG_PIN 5
#define ECHO_PIN 18

#define GREEN_LED 26
#define RED_LED 27

LiquidCrystal_I2C lcd(0x27, 16, 2);

long duration;
int distance;

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);

  pinMode(GREEN_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);

  lcd.init();
  lcd.backlight();

  lcd.setCursor(0,0);
  lcd.print("Smart Waste Bin");
  delay(2000);
  lcd.clear();
}

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

  duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.034 / 2;

  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("Distance:");
  lcd.print(distance);
  lcd.print("cm");

  if (distance < 10) {  
    digitalWrite(RED_LED, HIGH);
    digitalWrite(GREEN_LED, LOW);

    lcd.setCursor(0,1);
    lcd.print("Status: FULL ");
  } 
  else {
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(RED_LED, LOW);

    lcd.setCursor(0,1);
    lcd.print("Status: EMPTY");
  }

  delay(1000);
}