流水灯

int delaytime = 50;
void setup() {
// put your setup code here, to run once:
for(int a = 2;a<=6;a++){
pinMode(a,OUTPUT);
}

}

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

for(int a = 2;a<=6;a++)
{
digitalWrite(a,HIGH);
delay(delaytime);
digitalWrite(a,LOW);
delay(delaytime);
}

}