// This example lights up 8 leds in sequence. The leds
// are connected to digital i/o pins 0-7.

int p = 0;                    // holds which led is on


void setup() {  
  for (int i=0; i<8; i++) {   // set digital pins 0-7 as outputs 
    pinMode(i, OUTPUT); 
  }
}


void loop() {
  p++;                         // advance p to next pin
  p = (p+8) % 8;               // limit p between 0-7
  
  for (int i=0; i<8; i++) {
    if (i == p) {              // set pin p HIGH
      digitalWrite(i, HIGH);
    } else {
      digitalWrite(i, LOW);    // and all other pins LOW
    }
  }
  delay(200);                  // wait 200 millisecs
}