//https://www.youtube.com/watch?v=0Q9XhZ_gY_M

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

#define BACKLIGHT_PIN     13

LiquidCrystal_I2C lcd=LiquidCrystal_I2C(0x27, 20, 4); ;  // Set the LCD I2C address


 /* The circuit:
 * 5V to Arduino 5V pin
 * GND to Arduino GND pin
 * CLK to Analog #5
 * DAT to Analog #4
*/

//#include <LiquidCrystal.h> //Libraries
//LiquidCrystal lcd(2, 3, 4, 5, 6, 7); //Arduino pins to lcd

#define sensor_pin A0 

#define G_led 8 
#define R_led 9 

#define buzzer 13

float adcValue=0, val=0, mgL=0;

void setup(){// put your setup code here, to run once 

pinMode(sensor_pin, INPUT);

pinMode(R_led,OUTPUT); // declare Red LED as output
pinMode(G_led,OUTPUT); // declare Green LED as output
pinMode(buzzer,OUTPUT); // declare Buzzer as output 
lcd.init();
lcd.begin(16, 4); // Configura lcd numero columnas y filas
lcd.setBacklight(HIGH);

lcd.clear();
lcd.setCursor (5,0);
lcd.print("Welcome To");
lcd.setCursor (2,1);
lcd.print("Alcohol Detector"); 
delay(1500);
lcd.clear();
}

void loop(){
  
adcValue=0;
for(int i=0;i<10;i++){
adcValue+= analogRead(sensor_pin);
delay(10);
}

val = (adcValue/10) * (5.0/1024.0);
mgL = 0.67 * val;

lcd.setCursor(3, 0);
lcd.print("BAC: ");
lcd.print(mgL,3);
lcd.print("mg/L   ");


if(mgL>0.8){
lcd.setCursor(6, 1);
lcd.print(" Drunk");  

digitalWrite(buzzer, HIGH); 
digitalWrite(G_led, LOW); // Turn LED off.   
digitalWrite(R_led, HIGH);  // Turn LED on.
delay(300);
}else{
  lcd.setCursor(6, 1);
lcd.print("Normal    ");
  
digitalWrite(G_led, HIGH); // Turn LED on.  
digitalWrite(R_led, LOW);  // Turn LED off.
}
 
digitalWrite(buzzer, LOW);
delay(100);
}