Back in the summer, we hosted a HackTheCity event to understand the potential of "TheThingsNetwork," and how we as hackers, could create a device, which would harness the positive powers of LoRaWAN (Long Range Wide Area Network).
This month, we were thrilled to welcome back Sharon Mitchell (Postgraduate, Computational Foundry, Swansea University), who was inspired to create a prototype LoRaWAN/TTN IoT device, named "Jiggle" - designed for asset tracking.
What is LoRaWAN and how does it fit with LoRa Radio and TheThingsNetwork?
In its simplest terms,
"LoRaWAN is a standard for wireless communication that allows IoT devices to communicate over large distance, with minimal battery usage." @jens.be
It's an extension to the LoRa Radio standard; TheThingsNetwork is a free-to-use open source implementation of this protocol.
What are the main characteristics of LoRaWAN?
LoRaWan has an incredibly long range, it's secure, and has a battery life that could rival your watch - all for just a few pounds! Access to The Things Network is free, with LoRa-enabled devices available for little outlay. It offers device and App addressing which is useful, as you can send sensor data on to other web-services for mapping, graphing, logging etc.
So where's the hitch? Well, with any wireless communication, there is always a trade off between distance, speed and power - in turn giving variable data rates. However,
"LoRa was designed with use cases in mind where this data rate should be enough and the other characteristics are way more important." @jens.be
The Jiggle IoT device node : What is it, and how does it work?
"Jiggle, by means of a vibration sensor and GSM module, offers a Google map in a web browser with a map pin showing the last-known location of the Jiggle device (where it was when the vibration sensor woke the unit up). This offers better chance of asset recovery - for example, your bike - should it be stolen,” explains Sharon.
This costs fractions of a cent per page load, as Google is encouraging developers to access their APIs with their current offer of dollar-credit each month, so it’s essentially free to use right-now.
Small IoT devices, like Jiggle, are the perfect use case for LoRa. They require very low power to report information (in this case tracking) and as LoRa operates in an unlicensed radio band, it's possible to set up your own gateway for it to report to. Similar to regular WiFi, which also operates in unlicensed (ISM) radio-bands, anyone can install their own WiFi gateway, different from LoRa in the radio frequency of operation. (WiFi 2.4GHz, LoRa (in Europe) 870MHz).
The Gateway (where your device reports its information to!)
TechHub Swansea are one of only a handful of gateways in operation, in the region. The gateway, also known as an access point, is a small device that receives all LoRa radio sent by the devices in its range.
"Every gateway in the range of the signal sent out by a device will pick up the signal and process it, even if this LoRa gateway is part of a network that doesn’t know the device that sent the message." @jens.be
The beauty of gateways is that they can be DIY (all you need is a Raspberry Pi and an adaptor board from a company called RAK) and installed almost anywhere (subject to permission!) - they also need hooking up to your broadband connection for the backhaul.
Sharon is in the process of getting one of these DIY gateways installed onto the roof of the Engineering Department at the University’s Bay Campus. Jiggle (and any other LoRa node) will report to any LoRa gateway it can “see”, the same way your iPhone will try to hook-up with free WiFi in coffee shops or First Buses, if it can hear it, it will use it.
Stay tuned for the announcement of our next meet-up in the New Year - and have your chance to be involved in similar projects and to hear the progress with Jiggle!
We are also on the look out for some partners to help mobilise and grow HackTheCity in 2019. Please get in touch if your organisation can help! firstname.lastname@example.org
Merry Christmas and Happy New Year, see you in 2019 :)