Room Temp Controller
Arduino input

#include <LiquidCrystal.h>

const int temp_trans_pin = A0, Heater_pin = 13, FAN_pin = 6;

//Sets the desired Temp range between 15 and 20
float MinTemp =15, MaxTemp = 25;

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  lcd.begin(16, 2);
  pinMode(Heater_pin, OUTPUT);
  pinMode(FAN_pin, OUTPUT);
 //Displays the desired Temp range
  lcd.print("Room temp(C):");
  lcd.setCursor(2,1);
  lcd.print(MinTemp);
  lcd.print("-");
  lcd.print(MaxTemp);
delay(2000);
}

void loop() {
  float Eqv_volt, SensorTemp;
 //Reads the volatge and converts it to Temp
  Eqv_volt = analogRead(temp_trans_pin) * 5.0 / 1023;
  SensorTemp = 100.0 * Eqv_volt-50.0;
 //Displays the Sensor Reading
   lcd.clear();
  lcd.print("Sensor Reading:");
  lcd.setCursor(2, 1);
  lcd.print(SensorTemp);
  lcd.print("C");
delay(2000);
 //Compares the reading to the desired temp
  if(SensorTemp > MaxTemp){
    lcd.clear();
    lcd.print("temp is HIGHER!");
    //Turns on the FAN(dc motor)
    lcd.setCursor(0, 1);
    lcd.print("Turn on FAN!");
    for( int i = 0; i <= 255; i++){
      analogWrite(FAN_pin, i);
    }
    delay(3000);
     lcd.clear();
    lcd.print("Now temp is OK!");
    lcd.setCursor(0, 1);
    lcd.print("Turn off FAN");
    //Turns off FAN slowly
    for( int i = 255; i >= 0; i--){
      analogWrite(FAN_pin, i);
    }
    delay(2000);
  }
  else if(SensorTemp < MinTemp){
    lcd.clear();
    lcd.print("temp is LOWER!");
    lcd.setCursor(0, 1);
    lcd.print("Turn on HEATER!");
    //Turn on Heater(LED)
    digitalWrite(Heater_pin, HIGH);
    
    delay(3000);
    
    lcd.clear();
    lcd.print("Now temmp is OK!");
    lcd.setCursor(0, 1);
    lcd.print("Turn off HEATER!");
    delay(1000);
    digitalWrite(Heater_pin, LOW);
    lcd.clear();
  }
 //Temp is in perfect range so devices turned off
  else if(SensorTemp > MinTemp && SensorTemp < MaxTemp){
    lcd.clear();
    lcd.print("Temp is NORMAL");
    lcd.setCursor(2, 1);
    lcd.print("Turn off all!");
    delay(1000);
    lcd.clear();
  }
 
//Something went wrong in the circuit
  else {
    lcd.clear();
    lcd.print("Something went");
    lcd.setCursor(2, 1);
    lcd.print("WRONG in the ckt");
    delay(1000);
    lcd.clear();
  }
  delay(1000);
}