I Built a Digital Clock Inside a Glass Dome, and I named it YUMO GLOBE. Hand-Bent Brass Wire, ESP32-C3, 7-segment display, NTP Sync and LED Animations.

YUMO GLOBE is a handcrafted desk gadget and digital clock built around a hand-bent 1.5mm brass wire sculpture housed inside a glass dome. Powered by an ESP32-C3 Super Mini, it features auto-timekeeping via NTP, custom hardware-multiplexed 7-segment display control, and multi-stage SK6812 LED lighting effects. No 3D printing or CNC was used—just raw brass rod, a turned wooden base, and freeform soldering.

Check out the full build video on YouTube and grab the complete open-source code on GitHub!

📺 Watch the full build: https://www.youtube.com/watch?v=EUGc3DatJw4

💾 Source code: https: https://github.com/yumobuilds/YUMO-GLOBE

Microcontroller: ESP32-C3 Super Mini

Display: 4-Digit 7-Segment Display (LTD-4608E or two 2-digit modules)

Lighting: 5× SK6812 Addressable RGB LEDs

Structure & Enclosure: 1.5mm $\times$ 300mm Brass Rods, Wooden Base, Glass Dome Stand/Cloche

Power: 18650 3.7V Li-ion Battery, 18650 Charger/Boost Module

Tools: Soldering iron, flux, wire benders/pliers, wire cutters, heat gun

Software: PlatformIO / VS Code

-ESP32-C3 Super Mini https://www.amazon.co.uk/dp/B0DDL7WNZX

-2-Digit 7-Segment Display https://www.amazon.co.uk/s?k=2-Digit+...

-SK6812 Addressable LEDs https://thepihut.com/products/neopixe...

-Brass Rods 1.5mm × 300mm https://www.amazon.co.uk/s?k=brass+ro...

-DC 3.7V 18650 Li-ion Battery https://www.amazon.co.uk/s?k=18650+3....

-18650 Li-ion Battery charger module https://www.amazon.co.uk/dp/B0DXC1JSB5

-Dome glass stand https://www.amazon.co.uk/dp/B0DWX567HV

brass wire bending . 1mm

1. Hand-bend 1.5mm brass rods to form the outer rings and meridian lines of the globe structure.
2. Solder the brass nodes securely together to build a rigid, freeform frame that fits cleanly under the glass dome.
3. Turn or shape the wooden base, routing a channel for the battery, charger module, and wiring underneath.

Mount the 4-digit 7-segment display into the center of the brass chassis.

Position 4× SK6812 addressable LEDs around the wooden base ring and 1× SK6812 at the top peak of the globe.

Wire the 18650 battery through the charging/boost module to feed regulated 5V/3.3V to the ESP32-C3 Super Mini and display pins.

Open the project in PlatformIO and pull the code from GitHub ([https://github.com/yumobuilds/YUMO-GLOBE](https://github.com/yumobuilds/YUMO-GLOBE)).

The firmware uses a hardware-multiplexed ISR at 333Hz to drive the 7-segment display, eliminating all display flicker regardless of background Wi-Fi or LED tasks.

Network connection is handled via WiFiManager (captive portal on first boot) with IP geolocation to automatically resolve local timezones and sync with NTP servers (pool.ntp.org).

The SK6812 LEDs execute multi-phase animations using FastLED:

1. Startup Sequence: Color-synced spinner (red $\rightarrow$ orange $\rightarrow$ gold), cool fill, countdown rainbow, neon burst, and white strobe.
2. Idle & Solo Modes: Top LED smoothly breathes through neon hues while base lights accent the structure.
3. Periodic Triggers: Triple-flashes every 30s, contrasting breathing pairs every 5 min, and a full neon light show every hour.

Once tested, mount the entire assembly onto the wood base and place the glass dome on top.