Thermodo: The coolest thermometer yet

iPhone accessories

thermodo.pngGiven the number of sensors packed into modern phones, a thermometer is an odd exclusion. We’ve got gyroscopes, accelerometers, GPS, light sensors… but we can’t even tell the temperature without connecting to the internet?

Thermodo is a clever little gadget that aims to redress this balance. Plug it into your phone, fire up the app and it’ll report in real time on the actual temperature. Not an estimate downloaded from the internet, but it will actually measure how warm it is in the room.

The Hardware

Thermodo is tiny. When connected to the keyring holder, it is about the size of a AAA battery – and when plugged into your headphone socket (that’s how it transmit data), it only sticks out by about a centimeter.

It all comes together elegantly. The inclusion of a keyring was brilliant – it means you can carry it around wherever you go, without having to worry about losing the tiny connector when other stuff is plugged into your phone. Using the headphone socket as the means of connection is very clever too – as it guarantees compatibility (at least on a hardware, if not software level) with an almost infinitely wide range of gadgets.

The only down side, of course, is that you can’t listen to music whilst using it. Though surely if you’re in need of a thermometer, you must be doing some sort of important science, so shouldn’t be concerning yourself trivialities like popular music in the first place.

The Software

The software side is pretty simple at the moment. The Thermodo has been designed as a piece of hardware that will work with a number of different apps – with an open software developers kit for coders to build in support to their own apps. (For example, perhaps purveyors of smart thermostats could build in Thermodo support in the future?).

There is though, an official Thermodo app that simply displays the temperature in the slickest way possible – no more squinting at some mercury in a tube of glass for you.


What’s lovely is that it’ll change colour based on the temperature, and there’s a lovely sloping graph showing real time measurements – with it increasing and decreasing with the temperature.

Every time you plug the device in, it’ll take a few seconds before it settles on a rough actual temperature – so, for example, if you’re coming in from a freezing outdoors, it may not be accurate immediately.

In settings, you can also enable correction for if your phone itself is getting warm – cancelling out the effect of a warm phone on measurements.

The app also links to other apps that support Thermodo – which at the moment, there appears to be only two: Shade, a weather forecasting app, and Hub which will apparently log your temperature measurements and save them to the Cloud. Which might be useful for meteorologists, I guess.

The Verdict

I went to Canada last month – it was the middle of the winter. Temperatures hit lows of -50 celsius at some points, and it was an extraordinary experience for a British person. Simply spending a couple of minutes outside would lead to your nose hair freezing. Thermodo would have been perfect for finding out exactly how cold it is – which would have leant credibility to my anecdotes about how inhospitable it was.

More broadly – if you need a thermometer (and to be honest, I am struggling to think of a reason why you might need one) and have a smartphone, you can’t really go wrong. At only $30 – about £18, it’s worth having “just in case”. A nifty little device.

James O’Malley
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