#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x3F,16,2);
int LOW_Level  = 340;//101
int High_Level = 400;//301
int val;
int ALCOHOL_SENSOR = A0;
#define greenLed D7
#define buzzer D0
#define redLed D5
#define yellowLed D6

void setup()
{
  lcd.init();
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Hello, world!");
  pinMode(greenLed, OUTPUT);
  pinMode(yellowLed, OUTPUT);
  pinMode(redLed, OUTPUT);
  pinMode(buzzer, OUTPUT);
  Serial.begin(9600);
  delay(10);
  lcd.clear();
}
void loop()
{
  val = analogRead(ALCOHOL_SENSOR);
  Serial.println(val);
  lcd.setCursor(0, 0);
  lcd.print("Level: ");
  lcd.print(val);
  lcd.print("   ");
  if (val < LOW_Level) {
    lcd.setCursor(0, 1);
    lcd.print("                ");
    lcd.setCursor(0, 1);
    lcd.print("Low Pollution");
    digitalWrite(greenLed, HIGH);
    digitalWrite(yellowLed, LOW);
    digitalWrite(redLed, LOW);
    noTone(buzzer);
  }
  else if (val > LOW_Level && val < High_Level ) {
    lcd.setCursor(0, 1);
    lcd.print("                ");
    lcd.setCursor(0, 1);
    lcd.print("Medium Pollution");
    digitalWrite(greenLed, LOW);
    digitalWrite(yellowLed, HIGH);
    digitalWrite(redLed, LOW);
    noTone(buzzer);
  }
  else if (val > High_Level) {
    lcd.setCursor(0, 1);
    lcd.print("                ");
    lcd.setCursor(0, 1);
    lcd.print("High Pollution");
    digitalWrite(greenLed, LOW);
    digitalWrite(yellowLed, LOW);
    digitalWrite(redLed, HIGH);
    tone(buzzer, 1000, 200);
  }
  delay(1000);
}