This is my second time playing with Arduino programming. My first encounter with Arduino is 2 years ago, building a simple audio visualizer from Windows sound.

ADDED: Animated GIF showing 1.6 seconds of the audio visualizer project two years ago. Can see the Uno board is not original Arduino Uno (it was bought by my former employer):

I think I have forgotten most part of Arduino programming, barely remember Arduino IDE and avrdude.
Thank you, Cytron!