barnowl1.0.0 • Public • Published
Technology-agnostic middleware for RFID, RTLS and M2M
barnowl converts RF decodings into software-developer-friendly JSON. It abstracts away all the complexity of radio protocols (ex: BLE, RFID, WiFi, ...) and vendor-specific infrastructure to provide developers with a simple, standardised data structure to build software applications.
barnowl outputs a real-time stream of raddec objects which facilitate any and all of the following applications:
- RFID: what is present, based on the device identifier?
- RTLS: where is it relative to the receiving devices?
- M2M: how is its status, based on any payload included in the packet?
barnowl 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 the keystone in the reelyActive technology platform, which includes a wealth of complementary software and hardware.
npm install barnowl
Even without any hardware, it's easy to get started. The following code will listen to simulated hardware and output packets to the console:
const Barnowl = ;let barnowl = ;barnowl;barnowl;
As output you should see a stream of raddec objects similar to the following:
transmitterId: "001122334455"transmitterIdType: 2rssiSignature:receiverId: "001bc50940810000"receiverIdType: 1numberOfDecodings: 1rssi: -60receiverId: "001bc50940810001"receiverIdType: 1numberOfDecodings: 1rssi: -66packets: "061b55443322110002010611074449555520657669746341796c656572"timestamp: 1547693457133
Regardless of the underlying RF protocol and hardware, the raddec specifies what (transmitterId) is where (receiverId & rssi), as well as how (packets) and when (timestamp).
Is that owl you can do?
While barnowl may suffice standalone for simple real-time applications, its functionality can be greatly extended with the following software packages:
- advlib to decode the individual packets from hexadecimal strings into JSON
- barnacles to distribute the real-time data stream via APIs and more
Where to listen?
barnowl includes a TestListener (see the Hello barnowl! example above) while all other listeners exist as separate software packages to keep the code as lightweight and modular as possible. The following table lists all these listener packages which integrate seamlessly with barnowl in just two lines of code.
|Listener package||Use with|
|barnowl-reel||reelyActive hardware (BLE, sub-GHz active RFID)|
|barnowl-hci||BLE radios on Linux computers (ex: Raspberry Pi, PC, ...)|
|barnowl-tcpdump||WiFi radios on computers that can run tcpdump|
Example: reelyActive hardware connected via serial port
const Barnowl = ;const BarnowlReel = ; // 1: Include the interface packagelet barnowl = ;barnowl;// 2: Add the specific listener with relevant optionsbarnowl;
Example: built-in BLE radio of a Raspberry Pi
const Barnowl = ;const BarnowlHci = ; // 1: Include the interface packagelet barnowl = ;barnowl;// 2: Add the specific listener with relevant optionsbarnowl;
Example: WiFi radio on computer with tcpdump installed
const Barnowl = ;const BarnowlTcpdump = ; // 1: Include the packagelet barnowl = ;barnowl;// 2: Add the specific listener with relevant optionsbarnowl;
Example: reelyActive hardware & tcpdump
barnowl supports multiple simultaneous listeners and will mix decodings of the same transmission from different sources provided that the enableMixing feature is enabled. For instance, the reelyActive Owl-in-One combines a BLE and WiFi source.
const Barnowl = ;const BarnowlReel = ; // 1: Include each of theconst BarnowlTcpdump = ; // interface packageslet barnowl = enableMixing: true ;barnowl;let uart = /* */; // In this case the uart is an emitter of 'data' events// 2: Add the specifics listener with relevant optionsbarnowl;barnowl;
barnowl supports the following options:
|enableMixing||false||Mix together decodings from the same transmitter|
|mixingDelayMilliseconds||1000||Maximum time for any decoding to spend in the mixing queue|
|minMixingDelayMilliseconds||5||Minimum time to delay between subsequent queue managements|
|encodeRaddecs||false||Output raddecs as hex strings rather than as JSON|
In most use cases, enableMixing should be set to true except under extreme memory constraints and/or when absolutely no processing delay can be tolerated. Mixing decodings into a single raddec provides lossless compression and promotes efficient data distribution and processing.
let barnowl = enableMixing: true ; // Recommended
What's in a name?
The Barn Owl has the best hearing of any animal tested. Since this middleware is effectively listening (via hardware 'ears') for all the wireless devices in a Smart Space, barnowl would seem a more than fitting name. Moreover, Wikipedia introduces the Barn Owl as "the most widely distributed species of owl, and one of the most widespread of all birds". An ambitiously inspiring fact considering our vision for a global crowdsourced infrastructure of Wireless Sensor Networks in the Internet of Things (IoT).
Don't think we can top that? Well check out this quote: "the barn owl is the most economically beneficial species to humans". Yes, apparently the U.S. Fish and Wildlife Service is prepared to argue so. Too ambitious? Well, consider this quote from Jeremy Rifkin: "What makes the IoT a disruptive technology in the way we organize economic life is that it helps humanity reintegrate itself into the complex choreography of the biosphere, and by doing so, dramatically increases productivity without compromising the ecological relationships that govern the planet."
If you're developing with barnowl check out:
- diyActive our developer page
- our node-style-guide for development
- our contact information to get in touch if you'd like to contribute
Copyright (c) 2014-2019 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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