chicken.ino

#define REL_PIN 12
#define LED_PIN 13
#define HOUR_MILIS (1000UL * 60 * 60)
#define ON_TIME_MILIS (1000UL * 60 * 20)

void setup() {
  pinMode(REL_PIN, OUTPUT);
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);
}

void loop() {
  digitalWrite(REL_PIN, LOW);
  delay(ON_TIME_MILIS);
  digitalWrite(REL_PIN, HIGH);
  //delay(HOUR_MILIS - ON_TIME_MILIS);
  delay(ON_TIME_MILIS);
}