@thermal-label/letratag-core

Core protocol encoder, status parsers, and media / device registries for DYMO LetraTag LT-200B — a BLE-only handheld label printer.

This package is the shared foundation used by the browser package @thermal-label/letratag-web. There is no Node package today (no Node BLE GATT transport in @thermal-label/transport yet).

Install

pnpm add @thermal-label/letratag-core

Quick start

import {
  encodeLabel,
  parseStatus,
  parseAdvertisingStatus,
  DEVICES,
} from '@thermal-label/letratag-core';
import { renderText } from '@mbtech-nl/bitmap';

const device = DEVICES.LT_200B;
const bitmap = renderText('Hello LetraTag', { headDots: 32 });

// `encodeLabel` returns the framed BLE payload: header + chunked body.
const payload = encodeLabel(bitmap, device.engines[0], {
  copies: 1,
  cut: true,
  mtu: 247, // BLE 4.2 negotiated link MTU
});

// Ship `payload` to the printer's write-without-response TX
// characteristic via your transport of choice.

API highlights

• encodeLabel(bitmap, engine, options) — full job encoder (header + directives + image + chunking).
• parseStatus(bytes) — 3-byte RX notification parser (job-result code).
• parseAdvertisingStatus(bytes) — 3-byte BLE advertising-data parser (cassette presence, battery, error flags — readable without a connection).
• DEVICES / findDevice(vid, pid) — device registry.
• MEDIA / findMediaBySku(sku) — media registry (10 LT cassettes).
• renderImage, renderText re-exported from @mbtech-nl/bitmap.

Wire protocol

The full protocol spec lives at thermal-label.github.io/letratag/protocol/letratag-bt. The encoder in this package implements that spec.

Documentation

Full TypeDoc reference, getting-started guide, and the wire protocol: thermal-label.github.io/letratag/core.

1 devices — 1 verified · 0 partial · 0 broken · 0 untested

| Model | Key | USB PID | Transports | Status | | --- | --- | --- | --- | --- | | LetraTag LT-200B | LT_200B | — | BT LE | ✅ verified |

Click any model to open its detail page on the docs site, where engines, supported media, and verification reports live. The same data backs the interactive cross-driver table.