#include <LiquidCrystal_I2C.h>

#define PR_PIN 2

const int punkt = 9; //ms
const int strich = punkt * 3;

const char alphabetArr[36] = {'A', 'B', 'C', 'D', 'E',
                    'F', 'G', 'H', 'I', 'J',
                    'K' ,'L', 'M', 'N', 'O',
                    'P', 'Q', 'R', 'S', 'T',
                    'U', 'V', 'W', 'X', 'Y', 
                    'Z', '1', '2', '3', '4', 
                    '5', '6', '7', '8', '9', '0'};

const String morseCodeArr[36] = {".-", "-...", "-.-.", "-..", ".",
                        "..-.", "--.", "....", "..", ".---",
                        "-.-", ".-..", "--", "-.", "---",
                        ".--.", "--.-", ".-.", "...", "-",
                        "..-", "...-", ".--", "-..-", "-.--",
                        "--..", ".----", "..---", "...--", "....-",
                        ".....", "-....", "--...", "---..", "----.", "-----"};

LiquidCrystal_I2C lcd(0x27, 20, 4);

int lichtAnZaehler = 0;
int lichtAusZaehler = 0;
String morseCode = "";

void setup() {
  Serial.begin(9600);
  pinMode(PR_PIN, INPUT_PULLUP);
  lcd.init();
  lcd.backlight();
}

char morseZuBuchstabe(String s)
{
  char ruckgabe = "";
  for (int i = 0; i < sizeof morseCodeArr; i++)
  {
    if (morseCodeArr[i] == s){
      Serial.print(alphabetArr[i]);
      ruckgabe = alphabetArr[i];
      return ruckgabe;
    }
  }
}

void loop() {
  int lichtAn = !digitalRead(PR_PIN);
  if (lichtAn > 0)
  {
    lichtAnZaehler++;
    lichtAusZaehler = 0;
  }else{
    lichtAusZaehler++;
    if ((lichtAnZaehler >= punkt) && (lichtAnZaehler < strich)) {
      morseCode += ".";
      Serial.print(".");
      lcd.clear();
      lcd.setCursor(10, 0);
      lcd.print("Punkt");
    } else if (lichtAnZaehler >= strich) {
      morseCode += "-";
      Serial.print("-");
      lcd.clear();
      lcd.setCursor(10, 0);
      lcd.print("Strich");
    } else {
        if(lichtAusZaehler == strich*5 || morseCode.length() == 5){
          if (morseCode.length() > 0){
            lcd.setCursor(10, 1);
            lcd.print(morseCode);
            lcd.print(morseZuBuchstabe(morseCode));
          }
          morseCode = "";
        }
      }
      lichtAnZaehler = 0;
    }

  //LCD Ausgabe
  lcd.setCursor(0, 0);
  lcd.print(lichtAn);

  lcd.setCursor(0, 1);
  lcd.print(lichtAnZaehler);

}