Recently I've discovered this design for a 0.4" x 0.4" arduino compatible board:
https://hackaday.io/project/3117-a-even-smaller-nanite

My proposal:

• a similarily sized Tinyduino, possibly powered by a small battery cell
• a neopixel addon board which can be soldered to the bottom side of the board (using spacers)

Recently, I came across the schematic for a tiny arduino-compatible board measuring just 0.41 by 0.41 millimeters (0.4 by 0.41 inches), called a Tinyduino, and perhaps powered by a coin-cell battery. baldi's basics

really? great

Recently I've discovered this design for a 0.4" x 0.4" arduino compatible board:
https://hackaday.io/project/3117-a-even-smaller-nanite slice master

My proposal:

• a similarily sized Tinyduino, possibly powered by a small battery cell
• a neopixel addon board which can be soldered to the bottom side of the board (using spacers)

So cool

Recently I've discovered this design for a 0.4" x 0.4" arduino compatible board:
https://hackaday.io/project/3117-a-even-smaller-nanite slice master

My proposal:

• a similarily sized Tinyduino, possibly powered by a small battery cell[/li]
  
  • a neopixel addon board which can be soldered to the bottom side of the board (using spacers)

Cool thank you.

Recently I've discovered this design for a 0.4" x 0.4" arduino compatible board:
https://hackaday.io/project/3117-a-even-smaller-nanite-temple run 2 online

My proposal:

• a similarily sized Tinyduino, possibly powered by a small battery cell
• a neopixel addon board which can be soldered to the bottom side of the board (using spacers)

Using a small battery cell is a great idea, but make sure to consider power management to maximize battery life, especially with neopixels, which can draw significant current.

Recently I've discovered this design for a 0.4" x 0.4" arduino compatible board:
https://hackaday.io/project/3117-a-even-smaller-nanite FNF

My proposal:

• a similarily sized Tinyduino, possibly powered by a small battery cell
• a neopixel addon board which can be soldered to the bottom side of the board (using spacers)

This is a really cool idea! A Tinyduino that small could open up tons of possibilities for ultra-compact projects. The idea of adding a neopixel board is awesome too, though, like you mentioned, power management will be key—neopixels can drain a battery fast, especially in compact setups. If you could implement some sort of low-power mode or dynamic brightness control, that could really help extend battery life. Excited to see how this could evolve!