Morse Code Generator for Sonic Pi

gistfile1.rb

#MORSE CODE GENERATOR
#ENTER A MESSAGE AND PRESS RUN
message = 'Morse code is old'
  

#CUSTOMIZE
words_per_minute = 18 # slow:12, standard: 18, fast: 24
@u = 1.2 / words_per_minute #One time unit (length of 1 dot) 
@looped = true #comment out to play message only once
@pitch = 83
use_synth :beep

def play_message(message)
  loop do
    message.downcase.each_char do |character|
      play_one_character(character)
    end
    exit unless @looped
    sleep 36*@u
  end
end

def play_one_character(character)
  blip_sequence = ALPHABET[character]
  blip_sequence.chars.each_with_index do |blip,i|
    case blip
    when '.' then play_dot
    when '-' then play_dash
    when ' ' then play_blip_space
    end
    play_blip_space unless i == blip_sequence.length - 1
  end
  play_character_ending_space
end

def play_dot #1 time unit in length
  play @pitch, sustain: @u, release: 0.001; sleep @u
end

def play_dash #3 time units in length
  play @pitch, sustain: 3*@u, release: 0.001; sleep 3*@u
end

def play_blip_space #The time between blips: 1 time unit
  sleep @u
end

def play_character_ending_space #The time between characters: 3 time units
  sleep 3*@u
end

ALPHABET = {
  'a' => '.-',
  'b' => '-...',
  'c' => '-.-.',
  'd' => '-..',
  'e' => '.',
  'f' => '..-.',
  'g' => '--.',
  'h' => '....',
  'i' => '..',
  'j' => '.---',
  'k' => '-.-',
  'l' => '.-..',
  'm' => '--',
  'n' => '-.',
  'o' => '---',
  'p' => '.--.',
  'q' => '--.-',
  'r' => '.-.',
  's' => '...',
  't' => '-',
  'u' => '..-',
  'v' => '...-',
  'w' => '.--',
  'x' => '-..-',
  'y' => '-.--',
  'z' => '--..',
  ' ' => ' '
}

play_message(message)