Now-Playing appliance

A desk device that listens to the room, figures out what song is playing, and shows it: a HUB75 LED matrix renders a synced spectrum / lyrics visualization, and a 5" touch screen shows the cover, title, artist, progress and a mosaic of what played recently. The whole thing lives in a routed guitar body with three gold knobs and a bat-handle power toggle.

                       room audio
                           │
             ┌─────────────▼──────────────┐
             │  BOARD 1 — the room ear     │  ESP32-S3 running a WLED-MM fork:
             │  I2S mic · HUB75 64×32      │  spectrum / Keybeat / lyrics looks,
             │  panel · 3 knobs            │  uploads mic windows to the cloud
             └──────┬───────────────▲──────┘
      POST /ingest  │               │  GET /lyrics
                    │               │              UART (knobs, re-check, heartbeat)
             ┌──────▼───────────────┴──────┐        │
             │  CLOUD — recognition brain   │        │
             │  songrec → now-playing state │        │
             │  → metadata, lyrics, covers  │        │
             └──────┬───────────────▲──────┘        │
     GET /nowplaying│               │ GET /album/{id}│
             ┌──────▼───────────────┴──────┐        │
             │  BOARD 2 — the touch display │◄───────┘
             │  Raspberry Pi + 5" HDMI/USB  │  native LVGL app (display/)
             └─────────────────────────────┘

Both boards authenticate to the cloud with one shared device token. The cloud derives all state server-side; the boards render dumb.

What is in this repo

Path	What
BOM.md	The full parts list, with prices and sourcing notes
docs/assembly.md	Order the PCBs, solder them, wire the harness, drill the front panel, first power-on
docs/board1-firmware.md	Build, flash and provision the ESP32-S3 "ear"
docs/board2-display.md	Set up the Raspberry Pi and run the display app
docs/cloud.md	Running the recognition service and minting the shared token
hardware/carrier-board/	KiCad source + JLCPCB zip for the interconnect PCB (ESP32-S3 socket, power, HUB75, knobs, mic, Pi)
hardware/knob-board/	KiCad source + zip for the 3-encoder front-panel PCB. Also the front-panel drilling template
hardware/mic-board/	KiCad source + zip for the INMP441 breakout adapter
hardware/panelboard/ + docs/panelboard.md	The minimal build: a standalone HUB75 driver board for a stock ESP32-WROOM-32 dev board, runs upstream WLED-MM unmodified. Just the LED matrix, none of the rest
display/	The Board 2 display app (LVGL, C++). Runs on the Pi via DRM/KMS, and on a desktop as an SDL simulator

Build order

Only want the LED spectrum on a panel? Build the panelboard instead: one small PCB, a $5 ESP32 dev board, upstream WLED-MM, done. The rest of this list is the full appliance.

1. Read BOM.md and order everything. The three PCBs are bare boards from JLCPCB, roughly $20 for five of each, hand-soldered.
2. docs/assembly.md: solder the boards, make the four cables, wire power, mount the panel and screen.
3. docs/cloud.md: stand up the cloud service and create one device token. Both boards use it.
4. docs/board1-firmware.md: flash the ESP32-S3 and run the provisioning script. The panel should light up with the "Mountain" spectrum.
5. docs/board2-display.md: image the Pi, run provision.sh in display/. Play a song in the room.

Status and what is not here yet

This is a working one-off appliance and the design for a small hand-built batch. Every board in hardware/ has been fabbed and passes ERC/DRC with zero violations; the pin maps and current budgets are measured on the bench, not estimated.

Two source trees the build depends on are not published yet:

• The Board 1 firmware is a fork of WLED-MM carrying a room_mic_uploader usermod, the Keybeat and lyrics looks, and the HUB75 pin map. docs/board1-firmware.md documents the build exactly so it can be reproduced once the fork is pushed.
• The cloud service (Laravel + songrec). Its HTTP contract is documented in docs/cloud.md; the display app in display/ codes against it.

License

See LICENSE.