Although it’s not obvious in a still picture, the firmware now supports both the continuously changing colors of the Nissan fog lamp (mashed with tweaks from the vacuum tube lights) and the randomly changing colors from the LED matrix, both using SK6812 LEDs rather than the failing WS2812 modules:
Flash is a misnomer, as the tiles simply change from one color to the next, but I’ve never been adept at picking catchy names. In any event, the glass tiles on the left show nice pastel shades, in contrast to the bright primary(-ish) colors appearing on the right.
The colors are random numbers from 1 to 7, because 0 produces a somewhat ugly dark cell. The SK6812 modules have a white LED in addition to the RGB LEDs in the WS2812 modules, so I replace the “additive white” R+G+B color with the more-or-less true white (warm, for these modules) LED.
The new color goes into a cell picked at random (0 through 3, for 2×2 frames), except if the cell already holds the same color, whereupon a simple XOR flips the colors, except if the cell is already full-on white, whereupon it becomes half-on white to avoid going completely dark.
The glass tiles must change colors at a much slower pace than the 8×8 LED matrix, because there are so few cells; a random delay between 500 ms and 6 s seems about right.
They look really great in a dim room!
The Arduino source code as a GitHub Gist: