Just test is for 0b01111111 (=>pressed) and 0b11111111 (=> down) In the text you mention the Arduino Bounce library. But the Bounce library is obsolete (and I can’t find it anymore).

Debouncing button or switch inputs on microcontrollers can be a challenging problem for those first starting to program these devices. Part of the reason for this difficulty is that real-world butt… ...

In this quick Arduino tutorial I will explain how you can control a relay using the Arduino Board, one 1K and one 10K resistors, 1 BC547 transistor, one 6V or 12V relay, one 1N4007 diode and a 12V fan ...

Digi-Key Electronics has signed a worldwide distribution agreement with LogiSwitch, makers of the Arduino-friendly NoBounce line of ICs and switches. LogiSwitch’s adaptive NoBounce technology ...