#include "WiFi.h"

const char* ssid = "SSID";
const char* password = "PASSWORD";

long previousMillis = 0;
long interval = 30000;

void initWiFi(){
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid,password);
  Serial.print("Connecting to Wifi..");
  while(WiFi.status() != WL_CONNECTED){
    Serial.print(".");
    delay(1000);
  }
  Serial.println(WiFi.localIP());
}
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  initWiFi();
}

void loop() {
  // put your main code here, to run repeatedly:
  long currentMillis = millis();
  if ((WiFi.status() != WL_CONNECTED) && (currentMillis - previousMillis >=interval)) {
    WiFi.disconnect();
    WiFi.reconnect();
    previousMillis = currentMillis;
  }

}