An Arduino sketch that takes text input and flashes the internal LED and buzzes a buzzer in Morse code.
The digital output on pin 12 could operate a relay that could be connected to a radio Key input so it could send Morse code over the air.
Copyright Timothy Millea 2022 - Released under Creative Commons Attribution 4.0 International License
/*
Morse Code Sketch - Copyright Timothy Millea 2022 - Released under Creative Commons Attribution 4.0 International License
Takes a String variable and flashes on board led and buzzes passive speaker in morse code
INSTRUCTIONS
1. Open Serial Monitor console
2. Make sure New Line is selected a line termination
3. Enter sentence to convert to morse code
4. Press the enter key
*/
//define variables
int morseLED = 13; //onboard LED
int morseSND = 12; //pin for speaker
int WPM = 25; //default 13 words per minute
int multiplier = 1200 / WPM;
int delayInterSpace = 1 * multiplier;
int delayDIT = 1 * multiplier;
int delayDAH = 3 * multiplier;
int delayCharSpacing = 3 * multiplier;
int delayWordSpacing = 7 * multiplier;
bool stringComplete = false;
String inputString; // a string to hold incoming data
void setup() {
// put your setup code here, to run once:
pinMode(morseSND, OUTPUT); //speaker goes on this pin
pinMode(morseLED, OUTPUT); //onboard LED
Serial.begin(9600);
Serial.println();
Serial.println();
Serial.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
Serial.println(" MorseUNO");
Serial.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
Serial.println("~ Command mode");
Serial.println("Current commands:");
Serial.println("~WPM - lists current or sets new WPM speed (~WPM or ~WPM 25)");
Serial.println("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
Serial.print("Current WPM: ");
Serial.println(WPM);
flashSentence("MorseUNO");
Serial.println();
Serial.println("Ready!");
}
void loop() {
// put your main code here, to run repeatedly:
if (stringComplete) {
Serial.println("");
Serial.println(inputString);
if (inputString.startsWith("~")) {
//this is a command
inputString.toUpperCase();
inputString.remove(0, 1);
if (inputString.startsWith("WPM")) {
inputString.remove(0, 4);
inputString.trim();
if (inputString.toInt() == 0) {
Serial.print("Current WPM: ");
Serial.println(WPM);
return;
}
WPM = inputString.toInt();
Serial.print("Set WPM to: ");
Serial.println(WPM);
multiplier = 1200 / WPM;
delayInterSpace = 1 * multiplier;
delayDIT = 1 * multiplier;
delayDAH = 3 * multiplier;
delayCharSpacing = 3 * multiplier;
delayWordSpacing = 7 * multiplier;
}
} else {
flashSentence(inputString);
Serial.println("");
}
inputString = "";
stringComplete = false;
} //if read serial console complete
} //loop()
void flashLetter(char letter) {
//this isn't elegant but it gets the job done
Serial.print(letter);
if (letter == 'A') {
flashDIT();
flashDAH();
} else if (letter == 'B') {
flashDAH();
flashDIT();
flashDIT();
flashDIT();
} else if (letter == 'C') {
flashDAH();
flashDIT();
flashDAH();
flashDIT();
} else if (letter == 'D') {
flashDAH();
flashDIT();
flashDIT();
} else if (letter == 'E') {
flashDIT();
} else if (letter == 'F') {
flashDIT();
flashDIT();
flashDAH();
flashDIT();
} else if (letter == 'G') {
flashDAH();
flashDAH();
flashDIT();
} else if (letter == 'H') {
flashDIT();
flashDIT();
flashDIT();
flashDIT();
} else if (letter == 'I') {
flashDIT();
flashDIT();
} else if (letter == 'J') {
flashDIT();
flashDAH();
flashDAH();
flashDAH();
} else if (letter == 'K') {
flashDAH();
flashDIT();
flashDAH();
} else if (letter == 'L') {
flashDIT();
flashDAH();
flashDIT();
flashDIT();
} else if (letter == 'M') {
flashDAH();
flashDAH();
} else if (letter == 'N') {
flashDAH();
flashDIT();
} else if (letter == 'O') {
flashDAH();
flashDAH();
flashDAH();
} else if (letter == 'P') {
flashDIT();
flashDAH();
flashDAH();
flashDIT();
} else if (letter == 'Q') {
flashDAH();
flashDAH();
flashDIT();
flashDAH();
} else if (letter == 'R') {
flashDIT();
flashDAH();
flashDIT();
} else if (letter == 'S') {
flashDIT();
flashDIT();
flashDIT();
} else if (letter == 'T') {
flashDAH();
} else if (letter == 'U') {
flashDIT();
flashDIT();
flashDAH();
} else if (letter == 'V') {
flashDIT();
flashDIT();
flashDIT();
flashDAH();
} else if (letter == 'W') {
flashDIT();
flashDAH();
flashDAH();
} else if (letter == 'X') {
flashDAH();
flashDIT();
flashDIT();
flashDAH();
} else if (letter == 'Y') {
flashDAH();
flashDIT();
flashDAH();
flashDAH();
} else if (letter == 'Z') {
flashDAH();
flashDAH();
flashDIT();
flashDIT();
}
//numeral characters
else if (letter == '0') {
flashDAH();
flashDAH();
flashDAH();
flashDAH();
flashDAH();
} else if (letter == '1') {
flashDIT();
flashDAH();
flashDAH();
flashDAH();
flashDAH();
} else if (letter == '2') {
flashDIT();
flashDIT();
flashDAH();
flashDAH();
flashDAH();
} else if (letter == '3') {
flashDIT();
flashDIT();
flashDIT();
flashDAH();
flashDAH();
} else if (letter == '4') {
flashDIT();
flashDIT();
flashDIT();
flashDIT();
flashDAH();
} else if (letter == '5') {
flashDIT();
flashDIT();
flashDIT();
flashDIT();
flashDIT();
} else if (letter == '6') {
flashDAH();
flashDIT();
flashDIT();
flashDIT();
flashDIT();
} else if (letter == '7') {
flashDAH();
flashDAH();
flashDIT();
flashDIT();
flashDIT();
} else if (letter == '8') {
flashDAH();
flashDAH();
flashDAH();
flashDIT();
flashDIT();
} else if (letter == '9') {
flashDAH();
flashDAH();
flashDAH();
flashDAH();
flashDIT();
}
//punctuation characters
else if (letter == '$') {
flashDIT();
flashDIT();
flashDIT();
flashDAH();
flashDIT();
flashDIT();
flashDAH();
} else if (letter == '+') {
flashDIT();
flashDAH();
flashDIT();
flashDAH();
flashDIT();
} else if (letter == ',') {
flashDAH();
flashDAH();
flashDIT();
flashDIT();
flashDAH();
flashDAH();
} else if (letter == '-') {
flashDAH();
flashDIT();
flashDIT();
flashDIT();
flashDIT();
flashDAH();
} else if (letter == '.') {
flashDIT();
flashDAH();
flashDIT();
flashDAH();
flashDIT();
flashDAH();
} else if (letter == '/') {
flashDAH();
flashDIT();
flashDIT();
flashDAH();
flashDIT();
} else if (letter == ':') {
flashDAH();
flashDAH();
flashDAH();
flashDIT();
flashDIT();
flashDIT();
} else if (letter == ';') {
flashDAH();
flashDIT();
flashDAH();
flashDIT();
flashDAH();
flashDIT();
} else if (letter == '=') {
flashDAH();
flashDIT();
flashDIT();
flashDIT();
flashDAH();
} else if (letter == '?') {
flashDIT();
flashDIT();
flashDAH();
flashDAH();
flashDIT();
flashDIT();
} else if (letter == '@') {
flashDIT();
flashDAH();
flashDAH();
flashDIT();
flashDAH();
flashDIT();
} else if (letter == '!') {
flashDAH();
flashDAH();
flashDAH();
flashDIT();
}
} //flashLetter()
void flashWord(String word) {
//break word into chars
for (int i = 0; i < word.length(); i++) {
flashLetter(word.charAt(i));
delay(delayWordSpacing - delayCharSpacing);
} //for each character in word
} //flashWord()
void flashSentence(String text) {
int splitCount = countSplitCharacters(text, ' ');
String wordArray[splitCount + 1];
int index1 = 0;
int index2 = 0;
for (int i = 0; i < splitCount + 1; i++) {
//find the start and end index of the words by finding the space character
if (index1 > 0) {
index1 = text.indexOf(' ', index2);
}
index2 = text.indexOf(' ', index1 + 1);
if (index2 < 0) {
index2 = text.length();
}
//parse the word from the string
String word = text.substring(index1++, index2);
word.toUpperCase(); //convert to uppercase
wordArray[i] = word; //add word to array
} //for each word in sentance
for (int i = 0; i < splitCount + 1; i++) {
flashWord(wordArray[i]);
} //for each word in array
delay(delayWordSpacing);
} //flashSentence()
void serialEvent() {
while (Serial.available()) {
char inChar = (char)Serial.read();
if (inChar == '\n') {
stringComplete = true;
} //if we have a newline then we're done reading serial for now
if (stringComplete == false) {
inputString += inChar;
} //if no newline then append the char to the string
} //while stuff ready to read from serial console
} //serialEvent()
int countSplitCharacters(String text, char splitChar) {
int returnValue = 0;
int index = 0;
while (index > -1) {
index = text.indexOf(splitChar, index + 1);
if (index > -1) returnValue++;
}
return returnValue;
} //countSplitCharacters
void flashDIT() {
digitalWrite(morseSND, HIGH);
digitalWrite(morseLED, HIGH);
delay(delayDIT);
digitalWrite(morseSND, LOW);
digitalWrite(morseLED, LOW);
delay(delayInterSpace);
} //flashDIT()
void flashDAH() {
digitalWrite(morseSND, HIGH);
digitalWrite(morseLED, HIGH);
delay(delayDAH);
digitalWrite(morseSND, LOW);
digitalWrite(morseLED, LOW);
delay(delayInterSpace);
} //flashDAH()
