Cylon Eye 595

sketch.ino

const int pin_data = 2;
const int pin_clock = 3;
const int pin_latch = 4;

byte cylon = 0b10000000;
boolean right = true;

void output(byte data) {
  digitalWrite(pin_latch, LOW);
  shiftOut(pin_data, pin_clock, MSBFIRST, data);
  digitalWrite(pin_latch, HIGH);
}

void setup() {
  pinMode(pin_data, OUTPUT);
  pinMode(pin_clock, OUTPUT);
  pinMode(pin_latch, OUTPUT);
  
  digitalWrite(pin_latch, LOW);
}

void loop() {
  if (right) {
    cylon >>= 1;
    
    if (cylon == 0b00000001) {
      right = false;
    }
  } else {
    cylon <<= 1;
    
    if (cylon == 0b10000000) {
      right = true;
    }
  }
  
  output(cylon);
  delay(100);
}