int pin_01 = 7;
int pin_02 = 8;
int pin_03 = 3;
int my_delay_value = 1000;
int my_variable = 15;
void setup() {
  pinMode(pin_01, OUTPUT);
  pinMode(pin_02, OUTPUT);
  pinMode(pin_03, OUTPUT);
  Serial.begin(9600);
  Serial.print(my_variable);

}

void loop() {
  digitalWrite(pin_01, HIGH);
  delay(my_delay_value);
  digitalWrite(pin_01, LOW);
  delay(my_delay_value);

  digitalWrite(pin_02, HIGH);
  delay(my_delay_value);
  digitalWrite(pin_02, LOW);
  delay(my_delay_value);

  digitalWrite(pin_03, HIGH);
  delay(my_delay_value);
  digitalWrite(pin_03, LOW);
  delay(my_delay_value);
 
}