@embedded32/j1939

Educational SAE J1939 helpers for Embedded32: 29-bit ID parsing, a partial PGN catalog, message decoding, diagnostics subset, and CAN gateway bindings.

Scope: This is a learning-oriented subset - not a complete or certified J1939 stack.

Installation

npm install @embedded32/j1939 @embedded32/can

Minimum runnable example

import { parseJ1939Id, decodeJ1939, buildJ1939Id } from '@embedded32/j1939';

const parsed = parseJ1939Id(0x18f00401);
console.log(parsed.pgn, parsed.sa);

const msg = decodeJ1939({
  id: 0x18f00401,
  data: [0, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70],
  extended: true,
});
console.log(msg.name);

const id = buildJ1939Id({ priority: 6, pgn: 0xf004, sa: 0x00 });

Full walkthrough: examples/j1939-basic.ts - npx tsx examples/j1939-basic.ts

Public API overview

| Export | Role | | ----------------------------------- | ------------------------------------------------ | | parseJ1939Id, buildJ1939Id | 29-bit identifier math | | decodeJ1939, formatJ1939Message | Frame → structured message | | getPGNInfo | Catalog metadata for known PGNs | | J1939TransportProtocol | Multi-packet subset (BAM/RTS - partial coverage) | | DiagnosticsManager | DM1/DM2-oriented helpers | | J1939CANBinding | Connect CAN traffic to a runtime message bus | | AddressClaimManager | Address-claim teaching utilities |

Runtime requirements

• Node.js 18+
• ESM imports
• @embedded32/can when using CAN bindings or examples with frames

Hardware requirements

None for parse/decode examples. SocketCAN optional when using J1939CANBinding with real interfaces.

Browser compatibility

Decode functions are pure TypeScript and may be bundled for browser demos. SocketCAN and Node-only bindings are not browser-compatible.

Common errors

| Error | Fix | | ----------------------------- | ------------------------------------------------------------ | | unknown PGN / sparse decode | PGN not in catalog - check getPGNInfo | | Wrong priority/SA | Confirm hex ID (0x18F00401) and extended: true on frames | | Import J1939Id namespace | Use parseJ1939Id / buildJ1939Id functions instead |

Related packages

• @embedded32/can - frame transport
• @embedded32/sim - ECUs that emit J1939 traffic
• @embedded32/tools - simulate and j1939 monitor commands
• @embedded32/sdk-js - application-level J1939 client

Version compatibility

Use @embedded32/[email protected] with matching @embedded32/[email protected]. Transport and diagnostics APIs may expand in minor releases without breaking parse/decode.

License

MIT © Mukesh Mani Tripathi