//vars
unsigned long currentmillis = 0;
unsigned long beepmillis;
unsigned long lastWait = 0;
byte currentState = 0;
bool beeping = true;

void setup() {
  Serial.begin(115200);
  Serial.println("ready..");
  pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {

  currentmillis = millis();
  if (currentState > 6) currentState = 0;
  switch (currentState) {
    case 0: beeper(); break;
    case 1: lastWait = millis(); currentState++; break;
    case 2: wait(5000); break;
    case 3: beeper(); break;
    case 4: lastWait = millis(); currentState++; break;
    case 5: wait(5000); break;
    case 6: beeper(); break;
  }
}

void wait(int m) {
  if (currentmillis - lastWait >= m) {
    lastWait = millis();
    currentState++;
  }
}

void beeper() {
  //lee si el flag de beep está en 1
  if (beeping == true && currentmillis - beepmillis >= 1000UL) {
    digitalWrite(LED_BUILTIN, HIGH);
    beepmillis = millis();
    beeping = false;
  } else if ( currentmillis - beepmillis >= 1000UL) {
    beepmillis = millis();
    beeping = true;
    digitalWrite(LED_BUILTIN, LOW);
    currentState++;
  }
}