Arduino pips

ardupips.ino

void setup() {
  pinMode(6, OUTPUT);
  pinMode(10, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  digitalWrite(10, HIGH);
  delay(1000);

  timesignal();
  delay(2000);
  morse("M0LTE");
  
  delay(500);
  digitalWrite(10, LOW);
  
  while(true) {}
}

static const char* CHAR_TO_MORSE[128] = {
        NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
        NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
        NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
        NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
        NULL, "-.-.--", ".-..-.", NULL, NULL, NULL, NULL, ".----.",
        "-.--.", "-.--.-", NULL, NULL, "--..--", "-....-", ".-.-.-", "-..-.",
        "-----", ".----", "..---", "...--", "....-", ".....", "-....", "--...",
        "---..", "----.", "---...", NULL, NULL, "-...-", NULL, "..--..",
        ".--.-.", ".-", "-...", "-.-.", "-..", ".", "..-.", "--.",
        "....", "..", ".---", "-.-", ".-..", "--", "-.", "---",
        ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--",
        "-..-", "-.--", "--..", NULL, NULL, NULL, NULL, "..--.-",
        NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
        NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
        NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
        NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
};

void play(char inp){

  int cur=0;
  while(true){
    int asc = (int)inp;
    char c = CHAR_TO_MORSE[asc][cur];
    if (c == 0){
      return;
    }

    if (c == '.') {
      dit();
    } else {
      dah();
    }
    cur++;
  }
}

void morse(char msg[]){
  int i=0;
  while (true) {
    if (msg[i] == 0){
      return;
    }
    
    if (msg[i] == ' '){
      wordspace();
    } else {
      play(msg[i]);
      letterspace();
    }
    i++;
  }
}

void timesignal(){
  pip(100);
  delay(900);
  
  pip(100);
  delay(900);
  
  pip(100);
  delay(900);
  
  pip(100);
  delay(900);
  
  pip(100);
  delay(900);
  
  pip(500);
}

void pip(int ms){
  tone(6,1000,ms);
  delay(ms);
}

int ditlen=50;

void dit() {
 tone(6, 1000, ditlen);
 delay(ditlen);
 delay(ditlen);
}

void dah() {
 tone(6,1000,3*ditlen);
 delay(3 * ditlen);
 delay(ditlen);
}

void letterspace(){
  delay(3 * ditlen);
}

void wordspace(){
  delay(7 * ditlen);
}