# Brianna's LED Nameplate

A USB-C-powered desk decoration that spells out **BRIANNA** in green
LEDs. Plug a standard USB-C cable into the south edge and the seven
letters light up — no microcontroller, no firmware, no setup. ~700 mA
total on a 5 V rail, well within USB-C limits. Designed as an Adom
**molecule** so it fixtures into the standard workcell via four corner
machine-contact pins.

> **For AI handoff:** this page is the canonical writeup. If you're an
> agent picking up this project, everything you need to continue work
> — circuit decisions, BOM, build commands, file layout, known
> issues — is on this page. Source lives on the user's container at
> `/home/adom/project/adom-tsci-projects/Brianna-LED-Nameplate/`.

## Live 3D viewer

The interactive viewer at the top of this page (or the iframe section
below the brief, depending on template) is the full **adom-tsci**
3D viewer with the project's actual GLB, circuit.json, and
walkthrough loaded. It auto-plays the Walkthrough Demo on load —
component flyovers, USB-C / CC pulldown / status callouts, and the
Nets HUD x-ray view (substrate goes transparent, selected net glows
through the FR4). Use the toolbar to orbit, zoom, switch to PCB or
Schematic views, or open the Components / Nets HUDs manually. Pass
`?autoplay=off` to suppress the walkthrough.

![Top-down 3D render](/static/molecules/brianna-led-nameplate/3d.png)

## How it works

Each letter is rendered as a 3 × 5 LED bitmap (about 70 LEDs total),
laid out on a 3 mm grid. The font is a simple 3-wide bitmap embedded
in `lib/index.tsx` as a `FONT` const — the renderer walks each
letter's pixels and emits one `<led>` + one `<resistor>` per lit
pixel. Every LED has its own 300 Ω current-limiting resistor in
series, sized to drive a green LED at ~10 mA from the 5 V USB rail.
The resistors live in the inter-row gap below each LED to keep the
front face of the board clean and readable.

The seven letters themselves *are* the power indicator — when they're
glowing, the board has 5 V; when they're dark, it doesn't. There is
no separate status LED.

![PCB layout — top + bottom layers](/static/molecules/brianna-led-nameplate/pcb.png)

## Hardware summary

| Block | Part | JLCPCB | Notes |
|---|---|---|---|
| LEDs | green 0603 (~70 ea.) | — | one per lit pixel of the BRIANNA bitmap; Vf ≈ 2.1 V |
| Resistors | 300 Ω 0402 (~70 ea.) | — | one per LED, sets ~10 mA current |
| USB-C receptacle | TYPE-C-31-M-12 | C165948 | south edge, mouth cantilevered off the board |
| CC pulldowns | 5.1 kΩ 0402 ×2 | — | makes the cable identify the board as a downstream device |
| Bulk decoupling | 10 µF 0805 ×1 | — | smooths inrush as 70 LEDs light up together |
| Workcell pins | 4 × machine contact at corners | — | Adom standard 4-pin molecule fixturing |

## Mechanical

- **Board:** 100 × 38 mm, FR4, 2-layer
- **USB-C:** south edge, mouth points down (cable plugs in from below
  the board so the LEDs face the user)
- **Workcell-ready:** four corner machine-contact pins so the board
  fixtures cleanly on the Adom assembly cell
- **Top silkscreen:** "BRIANNA NAMEPLATE" caption above the LED
  letters, "5V IN ←" arrow next to the USB-C receptacle, MC1–MC4
  corner labels
- **Bottom silkscreen** (extensive — board is meant to explain itself
  when flipped over): "HOW TO POWER IT" 4-step list, "HOW IT WORKS"
  description, "BILL OF MATERIALS" listing every component family,
  "HOW IT WAS BUILT" credit to tscircuit + adom-tsci, "WORKCELL
  FIXTURING" pin info, "IF A LED GOES DARK" repair notes, safety
  warnings, footer with the wiki URL and Apple-style provenance line
  *Designed by Adom in Fort Worth, Texas*.

## Source layout

```
adom-tsci-projects/Brianna-LED-Nameplate/
  lib/
    index.tsx              ← board source — FONT bitmap, layout, traces
    UsbCReceptacle.tsx     ← TYPE-C-31-M-12 wrapper with rotation-aware cadModel
  package.json             ← @tsci/<author>.Brianna-LED-Nameplate, deps
  tscircuit.config.json    ← entrypoint config
  tsconfig.json            ← TS config, jsx=react-jsx
  walkthrough.json         ← Walkthrough Demo steps (manual, do_not_edit_by_hand)
  dist/lib/index/          ← build output (gitignored)
    circuit.json           ← canonical circuit data
    3d.glb                 ← GLB with 1024-px texture (default tsci build)
    pcb.svg, pcb.png       ← layout renders
    schematic.svg          ← schematic
  .npmrc                   ← @tsci registry pointer
```

## Build commands

```bash
# From the project directory:
cd adom-tsci-projects/Brianna-LED-Nameplate

# 1. Install deps (only needed once, or after package.json changes)
bun install

# 2. Build — produces dist/lib/index/{circuit.json, 3d.glb, pcb.svg, schematic.svg}
bunx tsci build lib/index.tsx --glbs --svgs --3d-png --pcb-png

# 3. Preview interactively (Hydrogen webview):
adom-tsci start . --port 8861 --tsci-port 3061 --texture-resolution 4096

# 4. Publish updated viewer to this wiki page:
adom-tsci export-wiki . \
  --slug brianna-led-nameplate \
  --page-type molecules \
  --label "Live 3D viewer"

# Optional flags:
#   --rebuild              force `bunx tsci build` first (slow on dense boards)
#   --texture-resolution N rebake board surface at N×N (4096 typical)
#   --no-upload            produce the .tar.gz only, skip the wiki upload
```

## Color options

Currently rendered in **green**. Other colors that work with the same
circuit (just swap the LED part and adjust the resistor for the new Vf):

| Color | LED Vf | Suggested R @ 10 mA |
|---|---|---|
| Red | ~2.0 V | 300 Ω |
| Yellow | ~2.1 V | 300 Ω |
| Green (current) | ~2.1 V | 300 Ω |
| Pink (e.g. XL-1608PIC-04) | ~3.0 V | 200 Ω |
| Blue | ~3.2 V | 180 Ω |
| White | ~3.0 V | 200 Ω |

To change color: edit `LED_COLOR` and `R_VALUE` constants at the top
of `lib/index.tsx`, rebuild, re-export.

## How to power it (when Brianna receives it in the mail)

1. Grab any USB-C cable — phone charger, laptop, USB-C wall wart.
2. Plug one end into the south edge of the board.
3. Plug the other end into a 5 V USB-C source.
4. **BRIANNA** lights up green.

Same instructions are silkscreened on the bottom of the board, in
case the package gets separated from the docs.

## Known issues / lessons learned

- **Each net is a 2-port LED↔resistor pair.** The board declares
  `<net name="VBUS"/>` and `<net name="GND"/>` in JSX, but the
  autorouter splits each LED's connection into its own pcb_trace so
  the Nets HUD lists 75 tiny nets instead of one mega-rail. The
  Nets-HUD auto-glow x-ray still works (substrate goes transparent,
  picks the largest net), but the highlighted segment is short. For
  a more dramatic glow effect, an explicit unified rail would help —
  unfilled feature request.
- **Courtyard overlaps:** the autorouter complains about LED+R
  courtyards overlapping at the 3 mm pixel pitch. This is cosmetic;
  the build still produces valid Gerbers. If it becomes a fab issue,
  bump pitch to 3.5 mm and shift R to (LED_x ± 1.5 mm).
- **Via-spacing DRC warnings:** a few via-pairs come out at <0.3 mm
  net-to-net spacing. Within most fab DRC; verify before a real
  fab run.

## Build provenance

- `@tsci/<author>.Brianna-LED-Nameplate` — built with
  [adom-tsci](https://wiki-ufypy5dpx93o.adom.cloud/apps/adom-tsci),
  Adom's tscircuit board viewer.
- Walkthrough authored manually in `walkthrough.json` (the
  auto-generator overwrites it; the file's `_meta.do_not_edit_by_hand`
  flag is intentionally false to preserve the hand-edited steps).
- 3D viewer bundle exported to this page via `adom-tsci export-wiki`
  (CLI v1.3.90+).

## Files attached to this page

**Source — recreate the molecule:**

- [plan.md](/static/molecules/brianna-led-nameplate/plan.md) — the original design brief, refinements, and out-of-scope notes
- [brianna-led-nameplate-source.tar.gz](/static/molecules/brianna-led-nameplate/brianna-led-nameplate-source.tar.gz) — full tscircuit project source: `lib/`, `package.json`, `tscircuit.config.json`, `tsconfig.json`, `walkthrough.json`, `.npmrc`, `plan.md`. Untar and `bun install && bunx tsci build` to recreate the GLB, PCB, and schematic from the same source the viewer above is showing.

**Build outputs:**

- [3d.glb](/static/molecules/brianna-led-nameplate/3d.glb) — full 3D model with 4096-px baked board surface
- [pcb.svg](/static/molecules/brianna-led-nameplate/pcb.svg) — flat PCB layout (vector)
- [pcb.png](/static/molecules/brianna-led-nameplate/pcb.png) — flat PCB layout (raster)
- [schematic.svg](/static/molecules/brianna-led-nameplate/schematic.svg) — circuit diagram
- [brianna-demo.mp4](/static/molecules/brianna-led-nameplate/brianna-demo.mp4) — 30-second narrated demo (early version, recorded before the wiki-embed flow shipped)

*Designed by Adom in Fort Worth, Texas.*