One of the core design considerations in this project is the way the LED ring is used to indicate different system states to the user, which in turn influences the requirements for the final hardware.

Microinteraction design has been discussed at length, particularly with regard to mobile application interfaces - in order to get a satisfying clicky feeling on a touchscreen device you are mostly constrained to tweaking the animations following a button press.

In our case we may not have the open-ended possibility of arbitrary animated graphics, but the NeoPixel ring does allow some flexibility in testing a variety of alternatives.

On the hardware side, we'll aim to have the simplest LED setup that will support the finalized animation. Using WS2812 LEDs isn't ideal from a power standpoint because the integrated controllers each draw around 2ma, even when the LEDs are off. I could throw in a transistor to cut the power when the LEDs are not in use, but there might not be any need for RGB LEDs anyway. The big benefit of the WS2812s is the single GPIO pin requirement. Of course there are a variety of multiplexing schemes out there, so depending on the number of LEDs in the final design the power savings over using WS2812s will probably be worth it. Ultimately the minimum LED setup will depend on the desired animation set.