#include <LiquidCrystal_I2C.h> 

float Vin=5.0;     // [V]        
float Rt=10000;    // Resistor t [ohm]
float R0=10000;    // value of rct in T0 [ohm]
float T0=298.15;   // use T0 in Kelvin [K]
float Vout=0.0;    // Vout in A0 
float Rout=0.0;    // Rout in A0
// use the datasheet to get this data.
float T1=273.15;      // [K] in datasheet 0º C
float T2=373.15;      // [K] in datasheet 100° C
float RT1=35563;   // [ohms]  resistence in T1
float RT2=549;    // [ohms]   resistence in T2
float beta=0.0;    // initial parameters [K]
float Rinf=0.0;    // initial parameters [ohm]   
float TempK=0.0;   // variable output
float TempC=0.0;   // variable output

int ledY = 3;
int ledO = 4;
int ledDG = 5;
int ledP = 6;
int ledR = 7;

LiquidCrystal_I2C lcd(0x27,16,2);

void setup() {
  lcd.begin(16,2);
  lcd.backlight();
  pinMode(0, INPUT);
  pinMode(ledY, OUTPUT);
  pinMode(ledO, OUTPUT);
  pinMode(ledDG, OUTPUT);
  pinMode(ledP, OUTPUT);
  pinMode(ledR, OUTPUT);
    //parâmetros
  beta=(log(RT1/RT2))/((1/T1)-(1/T2));
  Rinf=R0*exp(-beta/T0);
}

void loop()
{
  Vout=Vin*((float)(analogRead(A0))/1024.0); // calc for ntc
  Rout=(Rt*Vout/(Vin-Vout));

  TempK=(beta/log(Rout/Rinf)); // calc for temperature
  TempC=TempK-273.15;
    
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("Temperature: ");
    lcd.setCursor(0,1);
    lcd.print(TempC);
    lcd.write(0xdf); // to display °
    lcd.print("C ");
    lcd.print((TempC * 9)/5 + 32); // C to F
    lcd.write(0xdf);
    lcd.print("F"); 
    delay(1500);

    if (TempC <= -0) {
      digitalWrite(ledY, HIGH);
      digitalWrite(ledO, LOW);
      digitalWrite(ledDG, LOW);
      digitalWrite(ledP, LOW);
      digitalWrite(ledR, LOW);

      //lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("Temp: Very Cold");

      delay(1500);

    } else if (TempC <= 15) {
      digitalWrite(ledY, LOW);
      digitalWrite(ledO, HIGH);
      digitalWrite(ledDG, LOW);
      digitalWrite(ledP, LOW);
      digitalWrite(ledR, LOW);
      
      //lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("Temp: Cold");

      delay(1500);

    } else if (TempC <= 25) {
      digitalWrite(ledY, LOW);
      digitalWrite(ledO, LOW);
      digitalWrite(ledDG, HIGH);
      digitalWrite(ledP, LOW);
      digitalWrite(ledR, LOW);
      
      //lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("Temp: Normal");

      delay(1500);

    } else if (TempC <= 37) {
      digitalWrite(ledY, LOW);
      digitalWrite(ledO, LOW);
      digitalWrite(ledDG, LOW);
      digitalWrite(ledP, HIGH);
      digitalWrite(ledR, LOW);

      //lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("Temp: Hot");

      delay(1500);

    } else if (TempC >= 38) {
      digitalWrite(ledY, LOW);
      digitalWrite(ledO, LOW);
      digitalWrite(ledDG, LOW);
      digitalWrite(ledP, LOW);
      digitalWrite(ledR, HIGH);
      
      //lcd.clear();
      lcd.setCursor(0,0);
      lcd.print("Temp: Very Hot");

      delay(1500);

    }
    // else {
    //   digitalWrite(ledDG, HIGH);
    // }
    // delay(1500);
}