An Erlang script that uses morse code to send messages to @lelandbatey's keyboard.

keyboard_morse

#!/usr/bin/env escript

%%% USAGE: ./keyboard_morse STRING
%%% Uses morse code to send messages to a keyboard light that flashes
%%% when a web server request is made. See here[1] for details.
%%% This script could be modified to communicate with other kinds of
%%% devices by changing the emit_flash/0 function.
%%% 
%%% [1] http://lelandbatey.com/posts/2016/12/Making-lights-blink-for-each-HTTP-request/

main([Str]) ->
	inets:start(),
	send(list_to_morse(Str)),
	ok.

send([]) -> ok;
send([X|R]) ->
	emit_flash(),
	receive
		stop -> ok
	after (case X of long -> 1000; short -> 500 end) -> send(R)
	end.

emit_flash() ->
	httpc:request("http://lelandbatey.com/").

list_to_morse(Str) ->
	lists:flatten(
		lists:map(fun(X) -> char_to_morse(X) end, string:to_upper(Str))
	).

char_to_morse($A) -> [short, long];
char_to_morse($B) -> [long, short, short, short];
char_to_morse($C) -> [long, short, long, short];
char_to_morse($D) -> [long, short, short];
char_to_morse($E) -> [short];
char_to_morse($F) -> [short, short, long, short];
char_to_morse($G) -> [long, long, short];
char_to_morse($H) -> [short, short, short, short];
char_to_morse($I) -> [short, short];
char_to_morse($J) -> [short, long, long, long];
char_to_morse($K) -> [long, short, long];
char_to_morse($L) -> [short, long, short, short];
char_to_morse($M) -> [long, long];
char_to_morse($N) -> [long, short];
char_to_morse($O) -> [long, long, long];
char_to_morse($P) -> [short, long, long, short];
char_to_morse($Q) -> [long, long, short, long];
char_to_morse($R) -> [short, long, short];
char_to_morse($S) -> [short, short, short];
char_to_morse($T) -> [long];
char_to_morse($U) -> [short, short, long];
char_to_morse($V) -> [short, short, short, long];
char_to_morse($W) -> [short, long, long];
char_to_morse($X) -> [long, short, short, long];
char_to_morse($Y) -> [long, short, long, long];
char_to_morse($Z) -> [long, long, short, short];
char_to_morse($,) -> [long, long, short, short, long, long];
char_to_morse($.) -> [short, long, short, long, short, long].