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The tea totaller

We have many interests at ODI Leeds. One of our interests is the use of the Internet-of-things to connect sensors to the internet. We co-founded the Things Leeds & Bradford community which encourages the provision of a free LoRaWAN-based network across the two cities. As part of this we've worked with Bradford Council and Bradford University to help set up a flood sensor network in Bradford that measures water levels on Bradford Beck and in Bradford's Flood alleviation channel. But there are many more things that can be done with internet-connected sensors. Some are less serious.

We found a more frivolous use-case a couple of weeks ago. We had bought a Things Node as part of a Kickstarter project and hadn't made use of it yet. It consists of a button, a temperature sensor, and a light sensor. We already have a Microchip Mote monitoring the temperature and light levels of our space. For a while Amy has been suggesting that we record how many hot drinks we were consuming and a simple button seemed like it would do the job. And so the Tea Totaller was born.

Photo of our IoT button
Our Things Node in action

When the button is pressed it sends a radio packet to any Things gateway within range. The gateways pass the packet on to a Node-Red instance we have running on a server in York. The packet contains the fact that the button pressed, the temperature, and the light level. We add a datestamp to it and save it as JSON. Another piece of code then calculates various statistics about the data and pipes those into a visualisation on our website. This all happens pretty instantaneously.

The result is that we can see a breakdown of when and how often we make hot drinks. Over time we'll see if we make more hot drinks in the winter months, we'll find out if we live up to British stereotypes about the time of day we (and our co-workers) have our tea/coffee. We will also find out if the ambient temperature affects our hot drink making - do we make more when it is cold?

Counting cups of tea and coffee is clearly just a bit of fun but it isn't hard to think of more useful examples. Julian Tate (Things Manchester) has suggested that we could have LoRaWAN pressure sensors connected to stiles on Ilkley Moor so that the council could measure the amount of use they get (they currently do this by sending someone out with a clicker once in a while to count people). Internet-of-things doesn't have to just be about Smart Cities. The range and low-power usage of LoRaWAN devices can let us have Smart Moors and Smart Dales too.

A live visualisation of hot drinks made at ODI Leeds

Postscript: If you want to help improve Things Network coverage, you can build your own gateway or buy a pre-built Things Network Gateway from Farnell.