controlling relay with temperature

relays.erl

-module(relays).
-export([relay_one/0, handle_msg_one/2]).

relay_one() ->
   GPIO = gpio:open(),
   gpio:set_direction(GPIO, 2, output),
   handle_msg_one(GPIO, off).

handle_msg_one(GPIO, State) ->
   receive
       on ->
	 io:format("ON~n"),
          gpio:set_level(GPIO, 2, 1),
          timer:sleep(3000), 
          io:format("OFF~n"),
	 gpio:set_level(GPIO, 2, 0),
          handle_msg_one(GPIO, off);

       off ->
	 io:format("ON~n"),
          gpio:set_level(GPIO, 2, 1),
          timer:sleep(1000), 
          io:format("OFF~n"),
	 gpio:set_level(GPIO, 2, 0),
          handle_msg_one(GPIO, off);
      _ ->
          handle_msg_one(GPIO, State)
   after 1000 ->
       handle_msg_one(GPIO, State)
   end.

tph_reader.erl

-module(tph_reader).
-export([run/0]).

run() ->
 {ok, I2CBus} = i2c_bus:start(#{
 sda => 21,
 scl => 22
 }),
 {ok, BME} = bme280:start(I2CBus),
 loop(BME, hot).

loop(BME, LastState) ->
 case bme280:take_reading(BME) of
 {ok, Reading} ->
    {Temperature, Pressure, Humidity} = Reading,
    io:format("Temperature: ~pC, Pressure: ~phPa, Humidity: ~p%RH~n", [
        Temperature, Pressure, Humidity
    ]),
    case Temperature > 22.2 of
        true when LastState /= hot ->
           io:format("It's hot. Turn off Heat.~n"),
           RelaysPid = whereis(relays),
           RelaysPid ! off,
           loop(BME, hot);
        _ ->
           case Temperature < 21.5 of
              true when LastState /= cold ->
               io:format("It's cold. Turn on Heat.~n"),
               RelaysPid = whereis(relays),
               RelaysPid ! on,
               loop(BME, cold);
              _ ->
               timer:sleep(5000),
               loop(BME, LastState)
           end
    end;
 Other ->
    io:format("Error taking reading temperature: ~p~n", [Other]),
    loop(BME, LastState)
 end.