Morse code is a method of encoding text characters using symbols: dots and dashes. There are rules to distinguish the dots from dashes:
- The length of a dot is one-time unit
- The length of a dash is three-time units
- The space between symbols (dots and dashes) of the same letter is one-time unit
- The space between letters is three-time units
- The space between words is seven-time units
Each letter has a unique representation in the Morse code. The letter ‘S’ is formed of three dots, while the letter ‘O’ is of three dashes.
In a digital representation, the dots and dashes can be pulses (1 logic), while the spaces can be 0 logic. This translates to the following waveform:
The SOS message will be repeated continuously, which means the SOS waveform will be periodical. The period of the waveform is represented in the diagram above by the interval between the first and the last vertical dotted line.
Because the space between the words is seven-dot long, the period will have a length of 34 dots.