#define button 1 // PA5
#define led 10 // PA3

void short_delay() {
  delay(250);
}

void long_delay() {
  delay(750);
}

void short_beep() {
  digitalWrite(led, HIGH);
  short_delay();
  digitalWrite(led, LOW);
}

void long_beep() {
  digitalWrite(led, HIGH);
  long_delay();
  digitalWrite(led, LOW);
}

// based on Morse code chart: http://www.sckans.edu/~sireland/radio/code.html

void up(){
  // U
  short_beep();
  short_delay();
  short_beep();
  short_delay();
  long_beep();
  long_delay();

  // P
  short_beep();
  short_delay();
  long_beep();
  short_delay();
  long_beep();
  short_delay();
  short_beep();
  long_delay();
}

void down(){
  // D
  long_beep();
  short_delay();
  short_beep();
  short_delay();
  short_beep();
  long_delay();

  // O
  long_beep();
  short_delay();
  long_beep();
  short_delay();
  long_beep();
  long_delay();

  // W
  short_beep();
  short_delay();
  long_beep();
  short_delay();
  long_beep();
  long_delay();

  // N
  long_beep();
  short_delay();
  short_beep();
  long_delay();
}

void left(){
  // L
  short_beep();
  short_delay();
  long_beep();
  short_delay();
  short_beep();
  short_delay();
  short_beep();
  long_delay();

  // E
  short_beep();
  long_delay();

  // F
  short_beep();
  short_delay();
  short_beep();
  short_delay();
  long_beep();
  short_delay();
  short_beep();
  long_delay();
  
  // T
  long_beep();
  long_delay();
}

void right(){
  // R
  short_beep();
  short_delay();
  long_beep();
  short_delay();
  long_delay();

  // I
  short_beep();
  short_delay();
  short_beep();
  long_delay();

  // G
  long_beep();
  short_delay();
  long_beep();
  short_delay();
  short_beep();
  long_delay();

  // H
  short_beep();
  short_delay();
  short_beep();
  short_delay();
  short_beep();
  short_delay();
  short_beep();
  long_delay();

  // T
  long_beep();
  long_delay();
}

void setup() {
  // put your setup code here, to run once:
  pinMode(led, OUTPUT);
  pinMode(button, INPUT);
  Serial.begin(9600);
  digitalWrite(led, HIGH);
  while(!Serial.available()); // wait for serial
  String retrieve = Serial.readString();
  digitalWrite(led, LOW);
}

void loop() {
  // put your main code here, to run repeatedly:
  if(Serial.available()) {
    int result = Serial.parseInt();
    switch(result) {
      case 0: 
        up();
        break;
      case 1:
        down();
        break;
      case 2:
        left();
        break;
      case 3:
        right();
        break;
    }
    while(Serial.available()) {
      Serial.read(); // empty buffer
    }
  }
}