barnowl-impinj converts the decodings of any ambient RAIN RFID tags by Impinj readers supporting the IoT Device Interface (ex: R700) into standard developer-friendly JSON that is vendor/technology/application-agnostic.
barnowl-impinj 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. It is included in reelyActive's Pareto Anywhere open source middleware suite, and can just as easily be run standalone behind a barnowl instance, as detailed in the code examples below.
Follow our step-by-step tutorial to get started with barnowl-impinj or Pareto Anywhere using a the R700 reader:
Learn "owl" about the raddec JSON data output:
Clone this repository, install package dependencies with npm install, and then from the root folder run at any time:
npm start
barnowl-impinj will indiscriminately accept HTTP POSTs on localhost:3001/impinj and output (flattened) raddec JSON to the console.
Developing an application directly from barnowl-impinj? Start by pasting the code below into a file called server.js:
const Barnowl = require('barnowl');
const BarnowlImpinj = require('barnowl-impinj');
let barnowl = new Barnowl({ enableMixing: true });
barnowl.addListener(BarnowlImpinj, {}, BarnowlImpinj.HttpListener,
{ port: 3001 });
barnowl.on('raddec', (raddec) => {
console.log(raddec);
// Trigger your application logic here
});From the same folder as the server.js file, install package dependencies with the commands npm install barnowl-impinj and npm install barnowl. Then run the code with the command node server.js and observe the stream of radio decodings (raddec objects) output to the console:
{
transmitterId: "a00000000000000000001234",
transmitterIdType: 5,
rssiSignature: [
{
receiverId: "001625ffffff",
receiverIdType: 2,
receiverAntenna: 3,
rssi: -42,
numberOfDecodings: 1
}
],
timestamp: 1645568542222
}See the Supported Listener Interfaces below to adapt the code to listen for your reader(s).
The following listener interfaces are supported by barnowl-impinj. Extend the Hello barnowl-impinj! example above by pasting in any of the code snippets below.
The recommended implementation is using express as follows:
const express = require('express');
const http = require('http');
let app = express();
let server = http.createServer(app);
server.listen(3001, function() { console.log('Listening on port 3001'); });
let options = { app: app, express: express, route: "/impinj" };
barnowl.addListener(BarnowlImpinj, {}, BarnowlImpinj.HttpListener, options);Nonetheless, for testing purposes, barnowl-impinj can also create a minimal HTTP server as an alternative to express, and attempt to handle any POST it receives:
barnowl.addListener(BarnowlImpinj, {}, BarnowlImpinj.HttpListener,
{ port: 3001 });Provides a steady stream of simulated IoT Device Interface messages for testing purposes.
barnowl.addListener(BarnowlImpinj, {}, BarnowlImpinj.TestListener, {});In order to populate the raddec data structure, the following fields must be selected in the reader's Event Configuration:
| Field | Corresponding raddec property |
|---|---|
| Reader Hostname | receiverId & receiverIdType |
| EPC or TID | transmitterId & transmitterIdType |
| Antenna Port | receiverAntenna |
| Last seen time | timestamp |
| Peak RSSI | rssi |
While barnowl-impinj may suffice standalone for simple real-time applications, its functionality can be greatly extended with the following software packages:
- advlib-epc to decode the Electronic Product Code (EPC) into JSON
- barnowl to combine parallel streams of RF decoding data in a technology-and-vendor-agnostic way
These packages and more are bundled together as the Pareto Anywhere open source middleware suite, which includes a variety of barnowl-x listeners, APIs and interactive web apps.
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) 2022-2023 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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