#include "OneWire.h"
#include "DallasTemperature.h"

OneWire oneWire(0);
DallasTemperature ds(&oneWire);

unsigned long timer;

void setup() {
  Serial.begin(9600);
  pinMode(2, OUTPUT);
  ds.begin();
  timer = millis();
}

void loop() {
  if (millis()-timer > 400) {
    ds.requestTemperatures();
    if (ds.getTempCByIndex(0) >= 24) {
      digitalWrite(2, LOW);
    }
    else {
      digitalWrite(2, HIGH);
    }
    timer = millis();
  }
}