From telegraph wires to a Raspberry Pi on your desk ā the story of dots and dashes.
Morse code was developed in the 1830sā1840s by Samuel Morse and Alfred Vail for use with the electric telegraph. It encodes letters and numbers as sequences of short signals (dots) and long signals (dashes). Before telephones, radio, or the internet, Morse code was the fastest way to send messages across long distances.
Samuel Morse and Alfred Vail demonstrate the first practical telegraph system using coded signals.
The first official telegraph message is sent from Washington D.C. to Baltimore.
A standardised version is adopted internationally, becoming the global standard for telegraphy.
Morse code plays a critical role in maritime safety. The Titanic's distress calls used Morse code.
Used by amateur radio operators, in aviation, and as an accessibility tool. And now ā on a Raspberry Pi.
Each character is represented by a unique combination of short signals (dots ā written as .) and long signals (dashes ā written as -). A dash is three times the length of a dot.
The gap between symbols within a letter is one dot-length. Between letters it's three dot-lengths. Between words it's seven dot-lengths. In our project, we use 1.5-second and 3-second pauses.
Every letter and number used in this project:
| Letter | Morse Code |
|---|---|
| A | Ā· ā |
| B | ā Ā· Ā· Ā· |
| C | ā Ā· ā Ā· |
| D | ā Ā· Ā· |
| E | Ā· |
| F | Ā· Ā· ā Ā· |
| G | ā ā Ā· |
| H | Ā· Ā· Ā· Ā· |
| I | Ā· Ā· |
| J | Ā· ā ā ā |
| K | ā Ā· ā |
| L | Ā· ā Ā· Ā· |
| M | ā ā |
| N | ā Ā· |
| O | ā ā ā |
| P | Ā· ā ā Ā· |
| Q | ā ā Ā· ā |
| R | Ā· ā Ā· |
| S | Ā· Ā· Ā· |
| T | ā |
| U | Ā· Ā· ā |
| V | Ā· Ā· Ā· ā |
| W | Ā· ā ā |
| X | ā Ā· Ā· ā |
| Y | ā Ā· ā ā |
| Z | ā ā Ā· Ā· |
| Number | Morse Code |
|---|---|
| 0 | ā ā ā ā ā |
| 1 | Ā· ā ā ā ā |
| 2 | Ā· Ā· ā ā ā |
| 3 | Ā· Ā· Ā· ā ā |
| 4 | Ā· Ā· Ā· Ā· ā |
| 5 | Ā· Ā· Ā· Ā· Ā· |
| 6 | ā Ā· Ā· Ā· Ā· |
| 7 | ā ā Ā· Ā· Ā· |
| 8 | ā ā ā Ā· Ā· |
| 9 | ā ā ā ā Ā· |
| Signal | Morse Code |
|---|---|
| SOS (distress) | Ā· Ā· Ā· ā ā ā Ā· Ā· Ā· |
The letter E is just a single dot ā the shortest Morse character. That's because E is the most common letter in English, and Morse designed the code to be efficient.