# 2D board layout and manufacturing output

The PCB side of Fusion Electronics: the board editor, design rules, layer discovery, and every
artifact a fab or assembler needs.

## Getting to the board

```bash
adom-desktop fusion_aps_open   '{"query":"BQ25792"}'   # open the PROJECT (not the .brd)
adom-desktop fusion_show_2d_board '{}'                 # PCB editor
adom-desktop fusion_board_info '{}'                    # size, layer count, component count
```

Opening the `.brd` child directly gives an isolated view. See [schematics](schematics.md) for why.

## Design rules

```bash
adom-desktop fusion_load_design_rules '{}'                       # what is loaded now
adom-desktop fusion_set_design_rules  '{"preset":"adom"}'        # apply Adom's DRU
```

Adom's DRU rules ship with the bridge under `resources/`. Applying a house ruleset before routing is
what keeps a board manufacturable at the fab you use.

## Layers

`fusion_detect_layers` reports the real layer stack of the open board rather than assuming a
2-layer or 4-layer default. It is backed by a layer-detect ULP shipped in `resources/`.

`fusion_board_stackup` returns the physical stackup: per-layer thickness, copper weight and
material. This matters more than it sounds. When you render a board in 3D, the **board bbox is the
FR4 body**, never the whole assembly, because components overhang the edges and tower above it.
Getting that wrong produces a 3D model that looks correct and measures wrong.

Below is a real Adom board, the DRV8411A motor-driver, open in the Fusion Electronics 2D PCB
editor. The copper pours, routed traces, silkscreen and pad stack are all live and editable here,
which is where `fusion_electron_run` commands act.

![DRV8411A copper layout in the Fusion Electronics 2D editor](fz-2d.png)

## Routing

Fusion Electronics is EAGLE underneath, so routing is driven with EAGLE commands:

```bash
adom-desktop fusion_electron_run '{"command":"RATSNEST;"}'
adom-desktop fusion_electron_run '{"command":"AUTO ;"}'      # autoroute
```

`fusion_execute_text_command` is **space-delimited**. Note the space in `AUTO ;`.

## Manufacturing output

| verb | produces |
|---|---|
| `fusion_export_gerbers` | Gerbers + drill files, via a CAM job |
| `fusion_export_bom` | electronics BOM (this is the **electronics-only** one, see below) |
| `fusion_export_cpl` | component placement list for pick-and-place |
| `fusion_export_dxf` / `fusion_export_dwg` | 2D vector output |

JLCPCB CAM jobs ship with the bridge in `resources/`, so gerbers come out in the shape JLC expects
rather than a generic set you have to fix.

```bash
adom-desktop fusion_export_gerbers '{"outputPath":"C:/tmp/fab"}'
adom-desktop fusion_export_bom     '{"outputPath":"C:/tmp/bom.csv"}'
adom-desktop fusion_export_cpl     '{"outputPath":"C:/tmp/cpl.csv"}'
```

### `fusion_export_bom` is electronics-only

On a mechanical assembly it returns `No board open (current workspace: Design)`. That is expected.
For mechanical assemblies use [`fusion_assembly_bom`](mechanical-bom.md), which is kit-aware and
matches Fusion's Manage -> BOM.

## Publish the whole design, not just the 3D

When a board gets a wiki page, that page repo should carry **every** exportable file: `.f3d`/`.step`
/`.usdz`, EAGLE `.brd` + `.sch`, Fusion `.fbrd` + `.fsch`, gerbers, BOM, CPL, GLBs and renders. The
page exists so someone else can build the design, and a 3D model alone does not let them.

## Gotchas

- Wrong workspace is the usual cause of a refused verb. Check `isElectronics` in
  `fusion_get_app_state`.
- A blocking dialog (recovery prompt, update nag) will swallow commands silently. Clear it with
  `fusion_dismiss_blocking_dialogs`.
- Gerber export runs a CAM job and is genuinely slow on a dense board. A relay timeout at ~60s does
  not mean it failed; the work continues on the bridge, so poll.