ChronoBloom: A smart LED ring clock that nudges you to look up, take a break. ESP32-C3 with WebUI

Why this exists

I hyperfocus, and I lose hours to the wrong thing. Alarms don't work on me. A slow change of light in the room does. So the firmware has a 'nudge' (focus reminders) feature that fires visual nudge animations at intervals (and certain days) you set. So on Saturdays when I know I could get wrapped up in a project, the thing I reflexively look up to (clock) is also the device that subtly (not blaringly) does some cool, actual flower-patterned petals & animations. The nudge element is the feature the whole project is built around.

What it is

Three rings of addressable LEDs. Seconds and minutes share the outer 60, the way they share one track of marks on a real clock. The hour hand is an arrow-shaped spoke across the inner (12-LED) and middle (24-LED) rings, and a pixel sits in the center. The center pixel as it is now indicates the WIFI/connected status of the microcontroller (ESP32-C3), but could be repurposed to output something else. There's also a small place in the 3d-printed frame-ring part for installation of a lux sensor. A printed reflector behind them shapes the light into pointed hands, and a thin printed diffuser over the front softens it into a bloom.

That light sensor, and everything else, is set from a nicely packaged webUI where you can adjust the brightness, colors, themes and presets. The clock also syncs its own time over NTP whenever it is on WIFI. A decent amount of work was done on the backend with the themes and contrast settings: everything from the colors/hues of the rings, and also the animations for the quarter-half-hour 'chime' and nudge-reminders - with presets for contrasts and theme colors that 'match' well.

• Sets its own time over WIFI. No clock chip, no battery.

•  Seven face themes, six named for real flowers and built from their own colors.

•  Chimes on the quarter, the half and the hour.

•  Focus reminders: a soft light nudge at intervals you pick.

•  A light sensor dims it to the room. Pitch black and it sleeps.

•  No app and no account. The control page is served off the clock itself.

•  Flash it from a web page, then it updates itself over WIFI.

Start with the assembly 3MF, it has the profiles set but see print notes below. The largest part is 209 mm square, so a 220 mm bed is enough.

Printing Notes

Frame, reflector, back plate and stand

• Basic PLA, 0.2mm layers, no supports by design. Start from the assembly 3MF, it carries the orientation and profiles already.

The front diffuser

This is the part that makes the bloom, and the only fiddly one. Print it, don't skip it. A bare ring is just dots.

• White PLA. Other colors may be cool to experiment with, but white will give you the most true-to-design color output.

•  0.6mm is what works for me, but PLA scatters light differently brand to brand, so print a couple of thicknesses.

• Set the top and bottom surface fill to Monotonic, not Concentric. Some slicers quietly fall back to Concentric on a thin round part and you get swirl lines in the light. Check the sliced preview, not the settings panel.

• Solid through, no sparse infill gap in the middle. A gap reads as a bright streak.

• Flat on a smooth plate, around 100mm/s, first layer near 44mm/s.

Back plate

Print one or the other. The default has the cutout for the stand. The 2mm alternative has the button openings, for wall mounting. Both are in the assembly 3MF.

Electronics

• A Seeed XIAO ESP32-C3, a WS2812B ring set (the cheap 241-LED 9-ring kits give you the 60, the 24, the 12 and a loose pixel for the center), a VEML7700 light sensor, two momentary buttons, one 300 ohm resistor, and any 5V 2A USB-C phone charger. Around $50, and the ring kit is half of it.

• Nothing to install on your computer. Chrome or Edge on a desktop, plug in the USB-C cable, click Install.

Firmware, wiring and build guide: https://github.com/Maestro8484/ChronoBloom

Flasher: https://maestro8484.github.io/ChronoBloom/flasher/

The 15 inch version

• Same model at 198%, prints in thirds, and the face is laser-cut acrylic or a 0.5mm PLA sheet off an XXL printer. Experimental, and there is no step-by-step guide for it yet.

• 15 inch files: https://github.com/Maestro8484/ChronoBloom/tree/main/docs/publish/ChronoBloom_3D_Files/ChronoBloom_15inch

See it running:

The WebUI: