.NET 2.0+

Convert Text to Morse Code

Morse code is a standard encoding for letters, digits and some other characters that is ideally suited to radio transmissions and is used by amateur radio operators and pilots. This article describes a simple C# class for converting text to Morse code.

Morse Code

Morse code was developed by Samuel Morse and Alfred Vail in 1844 to allow sending of messages using their telegraph machine. Characters were encoded into a series of dots and dashes, which were converted to an electric current via the telegraph. A receiver transformed the electrical impulses into "dot" and "dash" indentations on paper tape that could be decoded manually. Later, the impulses were played as audible tones that could be sent via radio signals. Although modern technology has greatly reduced the requirement for the code, it is still used in aviation and by amateur radio operators.

In this article we will create a class that converts English letters and digits into International Morse code. The code will be represented using full stop (period) characters and hyphens. Individual characters will be separated with spaces and the ends of words will be represented with a slash character. For example, the Morse code for "Morse Code" will appear as:

This class could be used to encode Morse code before it is played back through the console speaker or sound card, or transmitted using a radio device.

Creating the Project

To begin, create a new console application and add a new class named "MorseConverter".

Initialising the Converter

There is no simple algorithm that can determine the dots and dashes of each Morse code character. Instead, a lookup table will be used. In the code, this lookup table will be stored in a Dictionary, with the letter or digit to be encoded as the key and the Morse code equivalent in the value. To declare the dictionary, add the following line to the MorseConverter class:

We can now initialise the dictionary values in the class' constructor. The following adds all English letters and digits. You could add further characters as desired.

public MorseConverter()
{
    _codes = new Dictionary<char, string>();
    _codes.Add('A', ".-");
    _codes.Add('B', "-...");
    _codes.Add('C', "-.-.");
    _codes.Add('D', "-..");
    _codes.Add('E', ".");
    _codes.Add('F', "..-.");
    _codes.Add('G', "--.");
    _codes.Add('H', "....");
    _codes.Add('I', "..");
    _codes.Add('J', ".---");
    _codes.Add('K', "-.-");
    _codes.Add('L', ".-..");
    _codes.Add('M', "--");
    _codes.Add('N', "-.");
    _codes.Add('O', "---");
    _codes.Add('P', ".--.");
    _codes.Add('Q', "--.-");
    _codes.Add('R', ".-.");
    _codes.Add('S', "...");
    _codes.Add('T', "-");
    _codes.Add('U', "..-");
    _codes.Add('V', "...-");
    _codes.Add('W', ".--");
    _codes.Add('X', "-..-");
    _codes.Add('Y', "-.--");
    _codes.Add('Z', "--..");
    _codes.Add('1', ".----");
    _codes.Add('2', "..---");
    _codes.Add('3', "...--");
    _codes.Add('4', "....-");
    _codes.Add('5', ".....");
    _codes.Add('6', "-....");
    _codes.Add('7', "--...");
    _codes.Add('8', "---..");
    _codes.Add('9', "----.");
    _codes.Add('0', "-----");
}