#include <LiquidCrystal_I2C.h>
#define LM35 A0
#define LED 12
LiquidCrystal_I2C lcd(0x27, 16, 2);
const float BETA = 3950;

void setup() {
  pinMode(LM35, INPUT);
  pinMode(LED, OUTPUT);
  lcd.init();
  lcd.backlight();
}

void loop() {
  int val = analogRead(LM35);
  float temp = 1 / (log(1 / (1023. / val - 1)) / BETA + 1.0 / 298.15) - 273.15;
  
  lcd.setCursor(0, 0);
  lcd.print("");
  
  if (temp > 25) {
    lcd.print("");
    digitalWrite(LED, HIGH);
  } else if (temp <= 10) {
    lcd.print("");
  } else {
    lcd.print("");
  }
  
  lcd.setCursor(0, 1);
  lcd.print("NhietDo: ");
  lcd.print(temp);
  
  delay(100);
}