packet-server.ino

#define READY 4
#define LATCH 5
#define DATA 6

void setup() {
  Serial.begin(9600);
  pinMode(READY, INPUT);
  pinMode(LATCH, OUTPUT);
  pinMode(DATA, OUTPUT);
}

void loop() {
  while(digitalRead(READY) != HIGH) {
    ;
  }

  char c = 'b';

  while(true) {
    for(int i = 0; i < 8; i++) {
      digitalWrite(DATA, c & (1 << i));
      digitalWrite(LATCH, HIGH);
      delay(100);
      digitalWrite(LATCH, LOW);
      delay(100);
    }
    
  }