Overview

The Pendant was my first attempt at some sort of universal portable microcontroller project that could be reused for much longer and just overall have a physical polish and robustness.

This project was created alongside development of Eclipse OS. I recommend checking out that doc first for a general overview of the software, which I believe is the real bread and butter of this whole thing. This doc will just focus on the hardware / specific implementation for the few events it's used in.

The Hardware

A modular prop made to easily create a central point of interface for all my LEDs, as well as giving an interface to the user for switching modes.

Processor

The device was using a Adafruit Feather RP2040. Very similar to a standard RP2040 (Raspberry Pi Pico), but this gave more flexibility with its lipoly charger and auto-charging hookup.

Components

There was a GC9A01 Round Screen in the center of two WS2812B LED rings. There are 4 momentary push button switches in the same housing. There is an external WS2812B connector for external lights, as well as a reversed WS2812B connector that is used for remote input that is threaded along the arm. The reversed connector ensures I am unable to incorrectly wire the device by accident.

3D Printing

The casing and main structure was completely self-architected. The case would snap a lid on both sides, as it was designed to snap-fit. The one on the front obviously had a large hole to see the screen and to avoid diffusing that light.

The design was originally made primarily for Neotropolis/Cyberarm. However, at a certain point the generalized "relic" design came through.

The Pattern Configuration

There were two sequential events coming up, so we had two configurations with custom patterns made for each event.

I liked the tree state management, it was relatively easy to navigate, although it could get a bit maze-like, so I tried to make state connections make sense thematically to help with memorizing the maze.

Projects

The Jacket v1

Apr 2024

 

The first iteration of The Jacket was made for a Cyberpunk style event called Neotropolis. It had 7 unique modes/patterns.

The Staff

May 2025

 

The second iteration was in the form of a wizard's staff and had 12 modes. Being able to make six new patterns in a month of off time, while working on a lot of other stuff for the second event, was nice — it was great to see the library prove itself out.

The Jacket v2 (Eclipse OS v2)

Apr 2025

The Jacket also used this device as a v2 version of the jacket from 2024, representing the completion of the EclipseOS library with 2D LED mapping and IO-agnostic patterns.