https://github.com/JFLABO/rubyex/blob/master/electro-devices-RUBIC-J-gogole%E4%BD%BF%E3%81%84%E6%96%B9%E3%83%9E%E3%83%8B%E3%83%A5%E3%82%A2%E3%83%AB-7%20(2).pdf