int a = 13; // LED pinint b = 10; // LED pinvoid setup() { // Setup LED pins pinMode(a, OUTPUT); pinMode(b, OUTPUT);}void loop() { // First: Gonna do this 5 times. for ( int i = 0; i < 5; i++ ) { // a ON, b OFF, 300ms duration digitalWrite(a, HIGH); delay(300); // a OFF, b ON, 300ms duration digitalWrite(a, LOW); digitalWrite(b, HIGH); delay(300); // Just turning the lights off // as a courtesy. digitalWrite(b, LOW); } // Hey, that happens to be useful // since we want 'off' for 1s. delay(1000); // You're doomed to repeat this part // forever. forever. forever. foreve while(true) { // a ON, b OFF, 50ms duration digitalWrite(a, HIGH); digitalWrite(b, HIGH); delay(50); // a OFF, b OFF, 50ms duration digitalWrite(a, LOW); digitalWrite(b, LOW); delay(50); // Lights are already off at the end // of this operation. Yay! }}