# pricegod-urovo-daemon

The **Windows** counterpart to the Mac `rfid-daemon`. Instead of a Chafon gun writing a
loose chip while a Dymo prints a separate sticker, this drives the **Urovo D812R+ (RFID)**
to **print the label AND encode the UHF chip in one pass** on the composite (paper+chip) rolls.

It listens on `http://localhost:7790/` with `CORS *`, so it's a drop-in for the PriceGod
extension's existing `daemon.js` client — same port, same JSON shape.

## Run it
Double-click **`start-daemon.cmd`** (leave the window open while you work). That's it —
no Node, no .NET SDK, no gitea clone. It's a self-contained `.exe`.

To rebuild after editing `daemon.cs`: double-click **`build.cmd`**.

## What's inside
- `daemon.cs` — the service (C#, .NET Framework 4.x).
- `pricegod-urovo-daemon.exe` — the compiled daemon.
- `GTSPL_SDK.dll`, `GTSPL_SDK_C.dll`, `zlib.net.dll` — the Gainscha/Urovo print SDK
  (must sit beside the .exe). Copied from the vendor Windows SDK.

The print/encode sequence is a straight port of the proven `gtcheck.cs` `rfidgo` path:
`SET RIBBON OFF` → continuous geometry (`GAP 0`, RFID rolls blind the optical gap sensor)
→ `writeUHF` → draw text + QR → `printlabel` → read-back verify.

## Routes
| method | path | body | returns |
|---|---|---|---|
| GET  | `/status`       | — | `{ok, ready, status, statusText, printer}` |
| POST | `/print-encode` | `{sku, releaseId, artist?, title?, price?, condition?, w?, h?, gap?}` | `{ok, sku, releaseId, epc, verified, status}` |
| POST | `/write-tag`    | alias of `/print-encode` (the daemon.js name) | same |
| GET  | `/read-tag`     | — | `{ok, epc, sku, releaseId, recognized}` |
| POST | `/calibrate`    | — | RFID auto-calibration |
| POST | `/recover`      | — | ribbon-off + one feed to clear a fault |

Quick test (PowerShell):
```powershell
Invoke-RestMethod http://localhost:7790/status
```

## SKU ↔ EPC scheme (⚠ verify)
The 96-bit EPC (12 bytes) is packed as: **6 bytes** 14-digit timestamp SKU · **4 bytes**
release_id · **2 bytes** `0xEC01` marker. This lives in the `Epc` class in `daemon.cs` and
is the **only** thing that needs to change if it must match a different (Mac/Chafon) layout —
nothing else depends on the byte order. Confirm by reading an existing tag: put a
Chafon-written record at the antenna and `GET /read-tag`.

## DYMO LabelWriter 450 on macOS — the PPD you will need again

Not the daemon, but it lives here because `mac/dymo.py` drives the same printer.

macOS auto-adds a USB LabelWriter 450 with the **generic** CUPS driver
(`*PCFileName: "dymo.ppd"`, `*ModelName: "DYMO Label Printer"`). That PPD ships 10 fixed
label sizes and **no** `CustomPageSize`/`VariablePaperSize` block — so a custom paper size
made in the macOS page-setup dialog can never reach the printer. CUPS silently falls back
to `w81h252` (Address, 28.6 × 88.9 mm), and a 54×24 mm label design comes out **rotated 90°
and shrunk**, with a big blank area. Nothing is wrong with the extension's `labels.js`.

`mac/dymo-24x55.ppd` is the generic PPD patched to add the shop's 24×55 mm price stock, in
both feed orientations, so the right one can be picked in the print dialog:

| PageSize | pt | mm | roll |
|---|---|---|---|
| `pg55x25`  | 72 × 155 | 25.4 × 54.7 | ~25 mm wide, label runs 55 mm along the feed |
| `pg55x25L` | 155 × 72 | 54.7 × 25.4 | ~55 mm wide, label runs 25 mm along the feed |

**John's price roll is the landscape-feed kind → use `pg55x25L`.**

```sh
sudo lpadmin -p <queue> -P mac/dymo-24x55.ppd      # apply  (queue on JING5: make_it_soso)
sudo lpadmin -p <queue> -m drv:///sample.drv/dymo.ppd   # revert to stock
```

**Re-apply after any macOS update or after re-adding the printer** — both revert the queue to
the generic driver and the symptom comes straight back.

Regenerate from the **pristine** driver PPD — once applied, the queue's own PPD is already
patched and `patch_ppd.py` will refuse it:

```sh
ppdc -d /tmp/ppdout /usr/share/cups/drv/sample.drv
python3 mac/patch_ppd.py mac/dymo-24x55.ppd /tmp/ppdout/dymo.ppd   # byte-identical, PASSes cupstestppd
```

Two traps it handles: margins are set to 2 pt sides / 4 pt ends instead of the driver's
stock 14.9 pt, which would eat 10.5 mm of a 55 mm label; and every one of the 31 languages
in `*cupsLanguages` needs a translation string per new choice or `cupstestppd` FAILs.

Dead end for next time: `LabelPrinter-*.pkg` in `~/Documents` is **not** the DYMO driver —
it's the generic bundle for the PM-246S/Wagtail printers.

## Notes / open items
- Default label geometry is `65×37 mm`, continuous (`GAP 0`). Adjust to your actual RFID
  roll via the `w`/`h`/`gap` fields, or change the `DEF_*` constants.
- The label layout (text lines + QR) is functional, not yet pixel-matched to the 51×19
  Dymo design in the extension's `labels.js`.
- The Chafon gun is still needed for **reading a loose tag off a shelf** — the Urovo can
  only read/write a tag physically inside the printer.