“It seems, that the main problem with microcontrollers for fan of electronics (especially beginners) is to find out where to apply them :) Nowaday electronics, especially digital one, is more and more looks like a black magic. Only 80-Lvl wisards are able to do something there with tiny components. That is a reason why Arduino boards become very popular. They encapsulate black magic and some smoke ;) into board with human-manageable pins. This post I want to devote to a fairly simple project, named PasswordKeeper, on the base of Aruino Pro Micro board. This board hosted ATmega32U4 chip.”