Originally written by Boris Smus. Updated and packaged by Alex Thorne as part of CodeSmith Summer Academy of Code, Oxford 2017. See http:https://smus.com/ultrasonic-networking for a discussion of the original idea and codebase.
- alphabet: set of characters that can be transmitted.
- char duration: how long a character is transmitted for.
- start character: the "message start" delimiter.
- end character: the "message end" delimiter.
Each message is a string of characters from the alphabet. Adjacent characters cannot be repeated.