Here’s an inexpensive Arduino-based MP3 Jukebox (translated) which [Jose Daniel Herrera] put together. He spent some time making ... to host the character LCD, rotary encoder, two buttons ...

I have to thank one author of a rotary encoder decoder (Ben Buxton). While his code seemed overly complex to my untutored eye, for example creating a new data type, it did show Arduino-novice ... will ...