ESP 8266 Wifi setup crash

Ticker standBy;

unsigned long interval=30000;

unsigned long lastMillis=0;

int rpm=0;

void setup() {

  Serial.begin(115200);

  attachInterrupt(digitalPinToInterrupt(4), ISR_Round,FALLING);

  standBy.attach(600, goToSleep);

}

void setup_wifi() {

  delay(10);

  // We start by connecting to a WiFi network

  Serial.println();

  Serial.print("Connecting to ");

  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {

    delay(500);

    Serial.print(".");

  }

  randomSeed(micros());

  Serial.println("");

  Serial.println("WiFi connected");

  Serial.println("IP address: ");

  Serial.println(WiFi.localIP());

}

void goToSleep(void)

{

  Serial.println("Publish Data and Go to sleep now");

  setup_wifi();

  //Publish MQTT

  ESP.deepSleep()

}

void loop() {

  if(millis()-lastMillis > interval)

  {

    Serial.println("Hallo");

    rpm=((roundCounter*2)/60);

    lastMillis=millis();

  }

}

void goToSleep(void)

{

TimerFlag=1;

}

void loop() {

  if(millis()-lastMillis > interval)

  {

    Serial.println("Hallo");

    rpm=((roundCounter*2)/60);

    lastMillis=millis();

  }

  if(TimerFlag==1)

  {

    Serial.println("Publish Data and Go to sleep now");

    setup_wifi();

    //Publish MQTT

    ESP.deepSleep()

  }

}