Easy to assemble glittering LED circle
Various circular animations and blinking multi-colour light effects are possible with this simple 32 LED circle. It runs from two CR2032 batteries. The red, yellow and green LEDs are driven by an ATmega328p, easily programmed with the Arduino IDE. Since this microcontroller lacks the outputs to drive so many LEDs individually, these are arranged in a 4 x 8 matrix (only 12 outputs required).