If you want to demonstrate your love for electronics and your partner at the same time, this projcet is for you. DIY GUY Chris shows you how to make ATtiny13 earrings. Here’s more from Instructables:
The circuit will be powered by a CR1220 Coin Cell Battery of 3V and this will not affect the data transmission from Attiny to WS2812 LED registers because considering the LED datasheet the smallest voltage for High level is 2.7V and the smallest voltage for low level is -0.3V then the 3V sent by Attiny to the LED registers will be well interpreted, the 3V will only affect the LED brightness but this is not a limit because I tested the LEDs with 3V power supply and it looks bright enough.