ale_halloween.erl

-module(ale_halloween).
-export([start/0]).

init() ->
        application:start(gproc),
        gpio:start_link({4, output}),
        gpio:start_link({17, output}),
        gpio:start_link({18, output}),
        gpio:start_link({27, output}),
        gpio:start_link({22, output}),
        gpio:start_link({23, output}).

set(Val) ->
        gpio:write(4, lists:nth(1, Val)),
        gpio:write(17, lists:nth(2, Val)),
        gpio:write(18, lists:nth(3, Val)),
        gpio:write(27, lists:nth(4, Val)),
        gpio:write(22, lists:nth(5, Val)),
        gpio:write(23, lists:nth(6, Val)).

blink() ->
        set([1,1,1,1,1,1]),
        io:format("LED on~n"),
        timer:sleep(1000),

        set([0,0,0,0,0,0]),
        io:format("LED off~n"),
        timer:sleep(1000).

play() ->
        set([rb(), rb(), rb(), rb(), rb(), rb()]),
        timer:sleep(500),
        play().

rb() ->
        random:uniform(2) - 1.

start() ->
        init(),

        io:format("blink test~n"),
        blink(),

        io:format("start pattern~n"),
        play().

gpio module is part of the Erlang/ALE framework, more information at: http://opensource.erlang-solutions.com/erlang_ale/