Got few LEDs laying around? Why not use them to make a 4x4x4 LED cube with the help of Arduino?
Yet another pin using an ATtiny.
Yet another Nyan Cat board with ATtiny85. This time using rechargeable battery and WS2812. <3
Cute heart-shaped jewelry with programmable LED sequence.
3D-printed Pikachu necklace with OLED display, Digispark and rechargeable battery. Custom your own animations with Arduino.
The I used what I had at home version of Adafruit's BMO. Using digispark board, LED matrix, buzzer with rechargeable battery.