unsigned long iT1 = 0;
unsigned long iT2 = 0;
boolean b1 = false;
boolean b2 = false;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(18, OUTPUT);
  pinMode(4, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
   delay(10); // this speeds up the simulation
      unsigned long iMls =millis();
      unsigned long per1 = 260;
      unsigned long per2 = 250;


      if ((iMls - iT1) >= per1) {
        iT1 = iMls;
        b1=!b1;
        if (b1==true){
          digitalWrite(18, HIGH);
        }
        else {
          digitalWrite(18, LOW);
        }
      }  
      
      if ((iMls - iT2) >= per2) {
        iT2 = iMls;
        b2=!b2;
        if (b2==true){
          digitalWrite(4, HIGH);
        }
        else{
          digitalWrite(4, LOW);
        }
      }  
      
  }