xmastree_with_picoruby.rb

GPIOS = [4, 5, 9, 11, 13]

sleep_range_start = 500
sleep_range_end = 5500
sleep_range = sleep_range_end - sleep_range_start + 1

seed = 1225
random = Proc.new { |seed| ((seed * 1103515245 + 12345) & 0x7fffffff) % sleep_range + sleep_range_start }

pins = {}
GPIOS.each do |no|
  seed = random.call(seed)
  pins[GPIO.new(no, GPIO::OUT)] = seed
end

sleep_mseconds = 300
loop do
  pins.each do |pin, slept|
    if slept < 0
      pin.write((pin.read - 1).abs)
      seed = random.call(seed).abs
      pins[pin] = seed
    end
    pins[pin] -= sleep_mseconds
  end

  if pins.keys.all? { |pin| pin.read == 0 }
    pins.keys.first.write 1
  end
  sleep_ms sleep_mseconds
end