// morse-decode-encode
// by Oompah
// March 3 2023
// credit to "Programming Arduino" by Simon Monk, (c)2016
//
// Either Key in a Morse code sequence using the button to decode,
// or click in the field in the Serial Monitor, and
// type letters followed by Enter to encode into Morse code.
// The LED and tone will sound while you key in the sequence.
// This sketch decodes sequences with letters or numbers
// and prints them to the serial monitor.
// A beep sounds and "?" prints for unrecognized sequences.
//
// To learn Morse Code, type a word in the Serial Monitor,
// Then try keying in the same word as you heard it.
// Tips:
//   Keep dots short, and dashes long.
//   Leave a short space after letters.
//   Leave a longer space after words.
//   Try to make nice clean presses and releases.
//
// Circuit:
// Piezo buzzer or speaker connects to pin 12 and GND
// LED (+) to pin 26, (-) through a 1k Ohm resistor to GND1

int tonePin = 12; // GPIO onde o buzzer positivo está conectado (por exemplo, GPIO12)
int toneFreq = 1000;
int ledPin = 26; // GPIO onde o LED positivo está conectado (por exemplo, GPIO26)
int debounceDelay = 30;

int dotLength = 240;
// dotLength = basic unit of speed in milliseconds
// 240 gives 5 words per minute (WPM) speed.
// WPM = 1200/dotLength.
// For other speeds, use dotLength = 1200/(WPM)
//
// Other lengths are computed from dot length
int dotSpace = dotLength;
int dashLength = dotLength * 3;
int letterSpace = dotLength * 3;
int wordSpace = dotLength * 7;
float wpm = 1200. / dotLength;

int t1, t2, onTime, gap;
bool newLetter, newWord, letterFound, keyboardText;
int lineLength = 0;
int maxLineLength = 20;

char* letters[] = {
    ".-", "-...", "-.-.", "-..", ".", "..-.", "--.", "....", "..",   // A-I
    ".---", "-.-", ".-..", "--", "-.", "---", ".--.", "--.-", ".-.", // J-R
    "...", "-", "..-", "...-", ".--", "-..-", "-.--", "--.."         // S-Z
};

char* numbers[] = {
    "-----", ".----", "..---", "...--", "....-", //0-4
    ".....", "-....", "--...", "---..", "----." //5-9
};

String dashSeq = "";
char keyLetter, ch;
int i, letterIndex;

void setup() {
    delay(500);
    pinMode(ledPin, OUTPUT);
    pinMode(tonePin, OUTPUT);
    Serial.begin(9600);
    Serial.println();
    Serial.println("-------------------------------");
    Serial.println("Morse Code decoder/encoder");
    Serial.print("Speed=");
    Serial.print(wpm);
    Serial.print("wpm, ");
    Serial.print("dot=");
    Serial.print(dotLength);
    Serial.println("ms");

    // Test the LED and tone
    tone(tonePin, toneFreq);
    digitalWrite(ledPin, HIGH);
    delay(2000);
    digitalWrite(ledPin, LOW);
    noTone(tonePin);
    delay(600);

    // Flash para demonstrar a velocidade esperada
    Serial.print("A .-  ");
    letterIndex = 'A' - 65;
    flashSequence(letters[letterIndex]);
    delay(wordSpace);

    Serial.print("B -...  ");
    letterIndex = 'B' - 65;
    flashSequence(letters[letterIndex]);
    delay(wordSpace);

    Serial.print("C -.-.  ");
    letterIndex = 'C' - 65;
    flashSequence(letters[letterIndex]);
    delay(wordSpace);

    Serial.println();
    Serial.println("-------------------------------");
    Serial.println("Click field in Serial Monitor,");
    Serial.println("type text and press Enter");
    Serial.println("-------------------------------");

    newLetter = false; //if false, do NOT check for end of letter gap
    newWord = false;  //if false, do NOT check for end of word gap
    keyboardText = false;
}

void loop() {
    // Check to see if something has been entered on the keyboard
    if (Serial.available() > 0) {
        if (keyboardText == false) {
            Serial.println();
            Serial.println("-------------------------------");
        }
        keyboardText = true;
        ch = Serial.read();
        if (ch >= 'a' && ch <= 'z') {
            ch = ch - 32;
        }

        if (ch >= 'A' && ch <= 'Z') {
            Serial.print(ch);
            Serial.print(" ");
            Serial.println(letters[ch - 'A']);
            flashSequence(letters[ch - 'A']);
            delay(letterSpace);
        }
        if (ch >= '0' && ch <= '9') {
            Serial.print(ch);
            Serial.print(" ");
            Serial.println(numbers[ch - '0']);
            flashSequence(numbers[ch - '0']);
            delay(letterSpace);
        }
        if (ch == ' ') {
            Serial.println("_");
            delay(wordSpace);
        }

        // Print a header after last keyboard text
        if (Serial.available() <= 0) {
            Serial.println();
            Serial.println("Enter text or Key in:");
            Serial.println("-------------------------------");
            keyboardText = false;
        }
    }

    // look for a gap >= letterSpace to signal end letter
    // end of letter when gap >= letterSpace
    gap = millis() - t2;
    if (newLetter == true && gap >= letterSpace) {

        //check through letter sequences to find matching dash sequence
        letterFound = false;
        keyLetter = '?'; // char '?' is for unrecognized sequence
        for (i = 0; i <= 25; i++) {
            if (dashSeq == letters[i]) {
                keyLetter = i + 'A';
                letterFound = true;
                break;    //don't keep checking if letter found
            }
        }
        if (!letterFound) {
            //now check for numbers
            for (i = 0; i <= 10; i++) {
                if (dashSeq == numbers[i]) {
                    keyLetter = i + '0';
                    letterFound = true;
                    break;    //don't keep checking if number found
                }
            }
        }
        Serial.print(keyLetter);
        if (!letterFound) {
            //buzz for unknown key sequence
            tone(tonePin, 100, 500);
        }
        newLetter = false; //reset
        dashSeq = "";
        lineLength++;
    }

    // keyed letter has been identified and printed
    // when gap is >= wordSpace, insert space between words
    // lengthen the word space by 50% to allow for variation
    if (newWord == true && gap >= wordSpace * 1.5) {
        newWord = false;
        Serial.print("_");
        lineLength++;

        // flash to indicate new word
        digitalWrite(ledPin, HIGH);
        delay(25);
        digitalWrite(ledPin, LOW);
    }

    // insert linebreaks
    if (lineLength >= maxLineLength) {
        Serial.println();
        lineLength = 0;
    }
}

void flashSequence(char* sequence) {
    int i = 0;
    while (sequence[i] == '.' || sequence[i] == '-') {
        flashDotOrDash(sequence[i]);
        i++;
    }
}

void flashDotOrDash(char dotOrDash) {
    digitalWrite(ledPin, HIGH);
    tone(tonePin, toneFreq);
    if (dotOrDash == '.') {
        delay(dotLength);
    } else {
        delay(dashLength);
    }

    digitalWrite(ledPin, LOW);
    noTone(tonePin);
    delay(dotLength);
}
//--- end of sketch ---