#define led1 13
#define led2 12
#define led3 11
#define led4 10
void setup() {
pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(led3, OUTPUT);
pinMode(led4, OUTPUT);
}
void loop() {
digitalWrite(led1, HIGH);
delay(100);
digitalWrite(led1,LOW);
delay(100);
digitalWrite(led2, HIGH);
delay(100);
digitalWrite(led2,LOW);
delay(100);
digitalWrite(led3, HIGH);
delay(100);
digitalWrite(led3,LOW);
delay(100);
digitalWrite(led4, HIGH);
delay(100);
digitalWrite(led4,LOW);
delay(100);
}