void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, robotronix.co.il");

   pinMode (4, OUTPUT);
}

void loop()
 {
  // put your main code here, to run repeatedly:

   digitalWrite (4, HIGH);	// turn on the LED , HIGH = 3.3V
      delay(500); // 1000 = 1 SEC --> 1000ms 

  digitalWrite (4, LOW);	// turn on the LED , LOW = 0V 
      delay(1000); // 1000 = 1 SEC --> 1000ms 
 
 }