barnacles-sparkplug distributes ambient IoT sensor data via MQTT observing the Eclipse Sparkplug specification.
barnacles-sparkplug ingests a real-time stream of dynamb objects from barnacles which it publishes via MQTT as Sparkplug B payloads. It couples seamlessly with reelyActive's Pareto Anywhere open source IoT middleware.
barnacles-sparkplug is a lightweight Node.js package that can run on resource-constrained edge devices as well as on powerful cloud servers and anything in between.
A common application of barnacles-sparkplug is to publish IoT data from pareto-anywhere as Sparkplug B payloads via MQTT. Simply follow our Create a Pareto Anywhere startup script tutorial using the script below:
#!/usr/bin/env node
const ParetoAnywhere = require('../lib/paretoanywhere.js');
// Edit the options to customise the server
const BARNACLES_SPARKPLUG_OPTIONS = {};
// ----- Exit gracefully if the optional dependency is not found -----
let BarnaclesSparkplug;
try {
BarnaclesSparkplug = require('barnacles-sparkplug');
}
catch(err) {
console.log('This script requires barnacles-sparkplug. Install with:');
console.log('\r\n "npm install barnacles-sparkplug"\r\n');
return console.log('and then run this script again.');
}
// -------------------------------------------------------------------
let pa = new ParetoAnywhere();
pa.barnacles.addInterface(BarnaclesSparkplug, BARNACLES_SPARKPLUG_OPTIONS);Clone this repository, then from its root folder, install dependencies with npm install. Start the Sparkplug client with the following command:
npm start
If a MQTT broker is running on localhost, the client should connect (without authentication) and publish a NBIRTH message. For convenience, a script to subscribe to Sparkplug messages (topic: spBv1.0/#) on localhost and print these to the console is provided, and can be started with the following command:
npm run subscribe
When both programs are run simultaneously, the latter will echo all Sparkplug messages to the console, starting with the NBIRTH message which will have the following format:
Topic: spBv1.0/iot/NBIRTH/paretoanywhere
{
timestamp: Long { low: 1735707600, high: 404, unsigned: true },
metrics: [],
seq: Long { low: 0, high: 0, unsigned: true }
}
The following simulated devices/sensors are supported for interface testing.
To simulate a Minew S1 temperature/humidity sensor, start barnacles-sparkplug with the following command:
npm run minew-s1
Simulated sensor c30000000051 will expose the following metrics:
| name | type |
|---|---|
| temperature | Double |
| relativeHumidity | Double |
| batteryPercentage | Double |
barnacles-sparkplug converts standard dynamb properties into the following Protobuf data types:
| Property | Data Type | Conversion |
|---|---|---|
| acceleration | DataSet of Double | Single-column |
| amperage | Double | none |
| angleOfRotation | Double | none |
| amperages | DataSet of Double | Single-column |
| batteryPercentage | Double | none |
| batteryVoltage | Double | none |
| distance | Double | none |
| elevation | Double | none |
| heading | Double | none |
| heartRate | Double | none |
| illuminance | Double | none |
| isButtonPressed | DataSet of Boolean | Single-column |
| isContactDetected | DataSet of Boolean | Single-column |
| isHealthy | Boolean | none |
| isMotionDetected | DataSet of Boolean | Single-column |
| isLiquidDetected | DataSet of Boolean | Single-column |
| levelPercentage | Double | none |
| magneticField | DataSet of Double | Single-column |
| numberOfOccupants | UInt32 | none |
| passageCounts | DataSet of UInt32 | Single-column |
| pressure | Double | none |
| pressures | DataSet of Double | Single-column |
| relativeHumidity | Double | none |
| speed | Double | none |
| temperature | Double | none |
| temperatures | DataSet of Double | Single-column |
| txCount | UInt32 | none |
| uptime | UInt32 | none |
| voltage | Double | none |
| voltages | DataSet of Double | Single-column |
barnacles-sparkplug supports the following options:
| Property | Default | Description |
|---|---|---|
| url | "mqtt://localhost" | Local MQTT broker |
| groupId | "iot" | See Sparkplug specification |
| edgeNodeId | "paretoanywhere" | See Sparkplug specification |
| clientId | "ParetoAnywhereEdgeNode" | Unique id of MQTT client |
| username | null | Optional for MQTT authentication |
| password | null | Optional for MQTT authentication |
| printErrors | false | Print MQTT errors? |
barnacles-sparkplug is based on the sparkplug-client open source Node.js package of the Eclipse Tahu project which is licensed under the Eclipse Public License v2.0 (EPL-2.0), and which we invite you to consider supporting at sparkplug.eclipse.org.
Discover how to contribute to this open source project which upholds a standard code of conduct.
Consult our security policy for best practices using this open source software and to report vulnerabilities.
MIT License
Copyright (c) 2025 reelyActive
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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