code :
int D1 = 11;
int D2 = 12;
int D3 = 13;
void setup() {
pinMode(D1,OUTPUT);
pinMode(D2,OUTPUT);
pinMode(D3,OUTPUT);
}
void loop() {
digitalWrite(D1,HIGH);//HIGH=1,LOW = 0
delay(100);// = 1s
digitalWrite(D1,LOW);
digitalWrite(D2,HIGH);
delay(100);// = 1s
digitalWrite(D2,LOW);
digitalWrite(D3,HIGH);//HIGH=1,LOW = 0
delay(100);// = 1s
digitalWrite(D3,LOW);
delay(100);
}
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