#define LED1 2
#define LED2 4
#define LED3 5
#define LED4 18
void setup() {
pinMode(LED1 , OUTPUT);
pinMode(LED2 , OUTPUT);
pinMode(LED3 , OUTPUT);
pinMode(LED4 , OUTPUT);
}
void loop() {
digitalWrite(LED1 , LOW);
digitalWrite(LED2 , LOW);
digitalWrite(LED3 , HIGH);
digitalWrite(LED4 , HIGH);
delay(500);
digitalWrite(LED1 , HIGH);
digitalWrite (LED2 , HIGH);
digitalWrite(LED3 , LOW);
digitalWrite(LED4 , LOW);
delay(500);
}