unsigned long Time1 =0;
int Intervals = 150;
int LED_pin =3;
byte LED_Status = 0;

void setup() 
{
  // put your setup code here, to run once:
 Time1 = millis();
 pinMode(LED_pin, OUTPUT);
}

void loop() 
{
  if (millis()-Time1 >= Intervals)
  {
   LED_Status =! LED_Status; 
   digitalWrite(LED_pin, LED_Status);
   Time1=millis(); 
  }

}