Music can soothe the soul… or something like that, but adding visual feedback in the form of a VU meter, according Adam Ples, “adds a little magic to any audio equipment.” This build allows you to add this effect without dealing with actual physical needles that bounce back and forth to the tunes, instead subbing in a pair of OLED modules with SSD1306 or SH1106 drivers.
The stated objectives of the project were, of course, to have two-channel operation and look as close to a real VU meter as possible. A final goal was to refresh at a high rate — 60 FPS or more — with no visible needle jumping, as is seen in other similar meter designs. While it’s perhaps difficult to truly appreciate its high frame rate without being there, it does look quite good on the video below.
The build arranges the two tiny OLED screens side-by side for each channel, with an adjustment knob, as well as a stereo line-in jack. The supporting PCB is populated with components including an ATmega88/168/328 microcontroller, and could possibly use an ATmega48 as well. There’s even an Arduino Uno shield version, but as with the rest of the project, it’s still something of a work-in-progress. Code is available via Ples’ write-up, though you’ll need to compile things properly according to your setup.