esrom/morse/lib/morse_signaler.ex

77 lines
1.7 KiB
Elixir

defmodule MorseSignaler do
alias Circuits.GPIO
@moduledoc """
Functions to control the signal lamp connected with GPIO.
"""
@sleep_short 200
@sleep_delay 400
@sleep_long 700
@sleep_pause 1000
@sleep_start 3000
@on 0
@off 1
@doc """
Signal the provided symbols using GPIO.
Notifies the parent when the signalling is done.
"""
def signal() do
{:ok, gpio} = GPIO.open(relay_pin(), :output)
GPIO.write(gpio, @off)
Process.sleep(@sleep_start)
update_progress(gpio, String.graphemes(secret_code()))
end
# Update progress for clients, and signals the rest of the sentence.
defp update_progress(gpio, symbols) do
100 - length(symbols) / String.length(secret_code()) * 100
|> MorseServer.update_progress()
if symbols != [] do
signal_sentence(gpio, symbols)
end
end
# Signal a whole sentence of symbols with GPIO.
defp signal_sentence(gpio, []) do
GPIO.write(gpio, @off)
GPIO.close(gpio)
update_progress(gpio, [])
:ok
end
defp signal_sentence(gpio, [symbol | rest]) when symbol in [".", "-"] do
GPIO.write(gpio, @on)
case symbol do
"." -> Process.sleep(@sleep_short)
"-" -> Process.sleep(@sleep_long)
end
GPIO.write(gpio, @off)
Process.sleep(@sleep_delay)
signal_sentence(gpio, rest)
end
defp signal_sentence(gpio, [" " | rest]) do
Process.sleep(@sleep_pause)
update_progress(gpio, rest)
end
defp signal_sentence(_gpio, [symbol | _rest]) do
{:error, "Undefined symbol: " <> symbol}
end
defp relay_pin() do
Application.fetch_env!(:morse, :relay_pin)
end
defp secret_code do
Application.fetch_env!(:morse, :morse_message)
end
end