An ATtiny85 is charged with running the LEDs, with the aid of an IP5306 chip to act as a boost converter for the lithium-ion battery supplying the juice.

This is all accomplished with a 4×4 neopixel matrix, run by an Attiny85 Digispark with a DS3231 RTC module keeping time. A slight simplification is required to reduce the glyphs to 4×4, but we ...