Arduino Controlled Telegraph, by George Theall, and Finn Snow

This antique telegraph is controlled by an Arduino. You can type a sentence into your computer in English, and the Arduino will translate it into Morse Code and tap it out in the traditional Dots and Dashes on a real antique Telegraph.

Arduino

USB -> Arudino connector

8 Arduino wires

5 Wires with alligator clips

2 Banana Plugs

Two telegraphs

1K Ω Resistor

Relay

Diode

Transistor

Computer with Arduino program

Please follow the diagram to carefully to set up the telegraph circuit.

Please follow the diagram to carefully to set up the Arduino circuit.

Connect the telegraph to the relay with alligator clips. The positive wire should connect to the moveable bar that connects to the finger plate (where someone would push to send a signal), and the negative wire should connect to the stationary metal at the base of the telegraph.

The code is written out in the following document. Upload the code to the Arduino and use the Serial Monitor to type a sentence. Click enter when you are done, and it will send your sentence to the telegraph in Morse Code.

int relayPin = 13; // Assign relayPin to pin 13. This is the power source for the relay


int timeUnit = 100; // This variable will be used to measure dots, dashes, breaks, and pauses
char input; // Variable to save the input to


void setup () {
Serial.begin(9600);//for the connect with the board
pinMode(relayPin,OUTPUT);
}


void loop () {
if (Serial.available()) {
input = Serial.read();//read the input
if (input == 'a' || input == 'A') {lA();}//if the input is a or A go to function lA
if (input == 'b' || input == 'B') {lB();}//same but with b letter
if (input == 'c' || input == 'C') {lC();}
if (input == 'd' || input == 'D') {lD();}
if (input == 'e' || input == 'E') {lE();}
if (input == 'f' || input == 'F') {lF();}
if (input == 'g' || input == 'G') {lG();}
if (input == 'h' || input == 'H') {lH();}
if (input == 'i' || input == 'I') {lI();}
if (input == 'j' || input == 'J') {lJ();}
if (input == 'k' || input == 'K') {lK();}
if (input == 'l' || input == 'L') {lL();}
if (input == 'm' || input == 'M') {lM();}
if (input == 'n' || input == 'N') {lN();}
if (input == 'o' || input == 'O') {lO();}
if (input == 'p' || input == 'P') {lP();}
if (input == 'q' || input == 'Q') {lQ();}
if (input == 'r' || input == 'R') {lR();}
if (input == 's' || input == 'S') {lS();}
if (input == 't' || input == 'T') {lT();}
if (input == 'u' || input == 'U') {lU();}
if (input == 'v' || input == 'V') {lV();}
if (input == 'w' || input == 'W') {lW();}
if (input == 'x' || input == 'X') {lX();}
if (input == 'y' || input == 'Y') {lY();}
if (input == 'z' || input == 'Z') {lZ();}
if (input == ' ') {wordPause();}
Serial.println (input);


}
}
//Letter functions
void lA () {dot();dash();letterPause();}//letter A in morse code!
void lB () {dash();dot();dot();dot();letterPause();}//same for B
void lC () {dash();dot();dash();dot();letterPause();}
void lD () {dash();dot();dot();letterPause();}
void lE () {dot();letterPause();}
void lF () {dot();dot();dash();dot();letterPause();}
void lG () {dash();dash();dot();letterPause();}
void lH () {dot();dot();dot();dot();letterPause();}
void lI () {dot();dot();letterPause();}
void lJ () {dot();dash();dash();dash();letterPause();}
void lK () {dash();dot();dash();letterPause();}
void lL () {dot();dash();dot();dot();letterPause();}
void lM () {dash();dash();letterPause();}
void lN () {dash();dot();letterPause();}
void lO () {dash();dash();dash();letterPause();}
void lP () {dot();dash();dash();dot();letterPause();}
void lQ () {dash();dash();dot();dash();letterPause();}
void lR () {dot();dash();dot();letterPause();}
void lS () {dot();dot();dot();letterPause();}
void lT () {dash();letterPause();}
void lU () {dot();dot();dash();letterPause();}
void lV () {dot();dot();dot();dash();letterPause();}
void lW () {dot();dash();dash();letterPause();}
void lX () {dash();dot();dot();dash();letterPause();}
void lY () {dash();dot();dash();dash();letterPause();}
void lZ () {dash();dash();dot();dot();letterPause();}


void dot() //Create a tap and delay for 100 milliseconds
{
digitalWrite(relayPin,HIGH); //turns the relay on, creating a tap on the telegraph
delay(timeUnit); //delays the dot so it is distinguishible from a dash
digitalWrite(relayPin,LOW); //turns the relay off
delay(timeUnit * 2); 
}


void dash() //Create a tap and delay for 300 milliseconds
{
digitalWrite(relayPin,HIGH); //turns the relay on, creating a tap on the telegraph
delay(timeUnit * 3); //delays the dash 3 times the delay of the dot 
digitalWrite(relayPin,LOW); //turns the relay off
delay(timeUnit * 4); 
}


void letterPause() //Delay between letters for 300 milliseconds
{
delay(timeUnit * 3);
}


void wordPause() //Delay between words for 700 milliseconds
{
delay (timeUnit * 7);
}

This code uses heavy inspiration from: https://www.deviceplus.com/arduino/how-to-create-a-morse-code-generator-using-arduino/