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