Morse translator

const int ledPin = 7;
const int piezoPin = 8;

const int dotDelay = 300;

const char* letters[] = {".-", "-...", "-.-.", "-..", ".", "..-.",
  "--.", "....", "..", ".---", "-.-", ".-..", "--", "-.", "---",
  ".--.", "--.-", ".-.", "...", "-", "..-", "...-", ".--", "-..-",
  "-.--", "--.."
};

const char* numbers[] = {
    "-----", ".----", "..---", "...--", "....-", ".....", "-....", "--...",
    "---..", "----."
};

void output(const char* code){
  for(int i=0; i<=sizeof(code); i++){
    int currDelay;
    if(code[i] == '.')
      currDelay = dotDelay;
    else if(code[i] == '-')
      currDelay = dotDelay*3;
    else
      return;

    digitalWrite(ledPin, HIGH);
    tone(piezoPin, 2000, currDelay);
    delay(currDelay);
    digitalWrite(ledPin, LOW);
    delay(dotDelay);
  }
  delay(dotDelay*2);
}

void setup(){
  pinMode(ledPin, OUTPUT);
  pinMode(piezoPin, OUTPUT);
  Serial.begin(9600);
  Serial.println("Ready.");
}

void loop(){
  char ch;
  if(Serial.available() > 0){
    ch = Serial.read();
    Serial.print("Character read: ");
    Serial.println(ch);
    if(ch >= 'a' && ch <= 'z'){
      Serial.print("Code: ");
      Serial.println(letters[ch-'a']);
      output(letters[ch-'a']);
    }else if(ch >= 'A' && ch <= 'Z'){
      Serial.print("Code: ");
      Serial.println(letters[ch-'A']);
      output(letters[ch-'A']);
    }else if(ch >= '0' && ch <= '9'){
      Serial.print("Code: ");
      Serial.println(numbers[ch-'0']);
      output(letters[ch-'0']);
    }
  }
}