Directory dependency graph for MoodRing:

Files
	auto_brightness.cpp

	auto_brightness.h

	layers.cpp

	layers.h

	mood_painter.cpp

	mood_painter.h

	mood_palette.cpp

	mood_palette.h

	MoodRing.ino
	A ring that listens to the room and lights the room back.

	ring_canvas.cpp

	ring_canvas.h

	ring_screenmap.cpp

	ring_screenmap.h

	room_sense.cpp

	room_sense.h

Detailed Description

A 244-LED ring that listens to the room and lights the room back.

The input is not "music". It is the room, whatever it sounds like: conversation, silence, laughter, clatter, a song coming on. MoodRing senses the room and paints a light response that cross-fades between three looks as the room changes. Design thread: issue #2256. Round-by-round design notes: DESIGN.md.

Architecture

Mic -> fl::audio::Processor
    -> RoomListener   fills RoomSense: smooth signals + calm/flow/groove weights
    -> MoodPainter    Breath, Flow, Groove layers mixed by weight, then trails + pulses
    -> ring

There is no state machine. calm, flow and groove are three weights that always sum to one, derived from two smoothed signals (presence and groove confidence) with asymmetric attack and release. The ring wakes on the first sound, settles slowly into calm, and never cuts between looks because the mix is continuous.

The three looks

Weight	When	Layer
`calm`	no sound present	Breath: whole-ring breath plus two slow soft blobs drifting in opposite directions. Audio does not drive it; silence looks intentional.
`flow`	sound present, no trustworthy beat	Flow: bass sets the size of two counter-rotating lobes, mids set their speed, treble scatters sparkle grains. Rising energy widens everything; falling energy tightens it.
`groove`	tempo and beat confidence both high	Groove: four markers step one slot per beat, the ring swells into each beat and releases after it, snares add thin counter-markers, downbeats flash the ring and spawn a wider pulse.

Colour comes from mood: valence picks the hue centre (cool for sad or tense, warm for happy), arousal picks saturation and hue spread.

Files

File	Purpose
`MoodRing.ino`	Wiring, UI, loop
`room_sense.{h,cpp}`	`RoomSense` and `RoomListener`: audio in, signals out
`mood_palette.{h,cpp}`	Mood to colour family
`ring_canvas.{h,cpp}`	Ring geometry and additive drawing helpers
`layers.{h,cpp}`	Breath, Flow and Groove layers
`mood_painter.{h,cpp}`	Layer mix, trails, beat pulses
`ring_screenmap.{h,cpp}`	Circular `ScreenMap` for the web preview
`auto_brightness.{h,cpp}`	Content-aware brightness compression

Run it

pip install fastled
cd examples/MoodRing
fastled

Grant microphone access when the browser asks, or drag a .wav onto the page. Turn on Debug: Print Sense to watch the signals and weights on the serial console at 2 Hz.