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

LiquidCrystal_I2C lcd(0x27, 16, 2);

#define lm35 A0
#define red 10
#define green 9
#define blue 8

void setup() {
  Serial.begin(9600);
  pinMode(red, OUTPUT);
  pinMode(green, OUTPUT);
  pinMode(blue, OUTPUT);
  lcd.init();
  lcd.backlight();
}

void loop() {
  int reading = map(analogRead(lm35), 0, 1023, -55, 150); // LM35 range −55C to +150C
  float tempC = reading;
  float tempF = (tempC * 9.0 / 5.0) + 32.0;

  lcd.setCursor(0, 0);
  lcd.print("Temp:");
  zeropadLCD(tempC);
  lcd.print(tempC);
  lcd.print("C");

  lcd.setCursor(0, 1);
  lcd.print("Temp:");
  zeropadLCD(tempF);
  lcd.print(tempF);
  lcd.print("F");

  Serial.print("Temperature:");
  zeropadMON(tempC);
  Serial.print(tempC);
  Serial.print("C");
  zeropadMON(tempF);
  Serial.print(tempF);
  Serial.println("F");

  if (tempC < 0) {
    digitalWrite(red, LOW);
    digitalWrite(green, LOW);
    digitalWrite(blue, LOW);
  }
  if (tempC >= 0 && tempC < 10) {
    digitalWrite(red, HIGH);
    digitalWrite(green, LOW);
    digitalWrite(blue, LOW);
  }
  else if (tempC >= 10 && tempC < 23) {
    digitalWrite(red, LOW);
    digitalWrite(green, HIGH);
    digitalWrite(blue, LOW);
  }
  else if (tempC >= 23 && tempC < 33) {
    digitalWrite(red, LOW);
    digitalWrite(green, LOW);
    digitalWrite(blue, HIGH);
  }
  else if (tempC >= 33) {
    digitalWrite(red, HIGH);
    digitalWrite(green, HIGH);
    digitalWrite(blue, HIGH);
  }
  delay(2000);
}

void zeropadLCD(float temp) {
  if (abs(temp) < 100)
    lcd.print(" ");
  if (abs(temp) < 10)
    lcd.print(" ");
  if (temp > 0)
    lcd.print(" ");
}

void zeropadMON(float temp) {
  if (abs(temp) < 100)
    Serial.print(" ");
  if (abs(temp) < 10)
    Serial.print(" ");
  if (temp > 0)
    Serial.print(" ");
}