This version fixes a security hole that could allow an attacker to view the codes as you enter them if you had a bluetooth or other wireless serial monitor attached to the Arduino. The new version, by default, hides codes in the serial output. This can be permanently disabled by setting the HIDE_CODES option at the top of the code to 0, or it can be temporarily disabled in use after entering the configuration code. When temporarily disabled, the reader will flash amber to warn that any codes entered may not be secure.