embedded32-bridge

Intelligent routing and bridging of J1939 CAN messages to Ethernet and MQTT.

Overview

Embedded32 Bridge connects the CAN bus to cloud and IoT infrastructure:

• CAN ↔ Ethernet - Bidirectional routing with filtering and rate limiting
• CAN ↔ MQTT - Topic-based message distribution with device discovery
• Rule Engine - Priority-based filtering, transformations, and selective routing
• J1939 Aware - Native PGN/SPN parsing and selective message propagation

Installation

npm install embedded32-bridge embedded32-ethernet embedded32-can embedded32-j1939

Usage

CAN-Ethernet Bridge

import { CanEthernetBridge } from 'embedded32-bridge';
import { CANBus } from 'embedded32-can';
import { UDPServer } from 'embedded32-ethernet';

const canBus = new CANBus({ interface: 'vcan0' });
const ethServer = new UDPServer(5000);

const bridge = new CanEthernetBridge({
  canBus,
  ethServer,
  pgnFilters: {
    whitelist: [0xF004, 0xFECA],
    blacklist: []
  },
  rateLimits: {
    0xF004: 10,  // 10 Hz for Engine Speed
    default: 5   // 5 Hz for others
  }
});

await bridge.start();

CAN-MQTT Bridge

import { CanMqttBridge } from 'embedded32-bridge';
import { CANBus } from 'embedded32-can';
import { MQTTClient } from 'embedded32-ethernet';

const canBus = new CANBus();
const mqtt = new MQTTClient({ broker: 'mqtt://localhost:1883' });

const bridge = new CanMqttBridge({
  canBus,
  mqtt,
  topicPrefix: 'fleet/truck1',
  pgnTopics: {
    0xF004: 'engine/speed',
    0xFECA: 'engine/controller'
  },
  deviceName: 'Truck ECU 1',
  payloadFormat: 'nanoproto'
});

await bridge.start();

Rule Engine

import { RuleEngine } from 'embedded32-bridge';

const engine = new RuleEngine({
  defaultAction: 'drop',
  rules: [
    {
      id: 1,
      priority: 100,
      pgn: 0xF004,
      action: 'forward',
      destinations: ['ethernet', 'mqtt'],
      rateLimit: 10
    },
    {
      id: 2,
      priority: 80,
      pgn: 0xFECA,
      spnFilter: [190, 191],
      action: 'forward',
      destinations: ['mqtt'],
      rateLimit: 1
    }
  ]
});

const decision = engine.route(canMessage);

Configuration Options

CanEthernetConfig

| Option | Type | Description | |--------|------|-------------| | canBus | CANBus | CAN interface instance | | ethServer | UDPServer | UDP server instance | | pgnFilters | object | Whitelist/blacklist PGNs | | rateLimits | object | Rate limit per PGN (Hz) | | statsInterval | number | Statistics reporting interval (ms) |

CanMqttConfig

| Option | Type | Description | |--------|------|-------------| | canBus | CANBus | CAN interface instance | | mqtt | MQTTClient | MQTT client instance | | topicPrefix | string | Base topic path | | pgnTopics | object | PGN to topic mapping | | deviceName | string | Device identifier | | payloadFormat | string | 'nanoproto' or 'json' |

License

MIT © Mukesh Mani Tripathi