Sensly: an air quality monitoring HAT

Altitude Technology have a very interesting Kickstarter campaign that’s just entering its final few days. It’s for an Internet of Things air quality monitoring device called Sensly, and one of the interesting things about it is that it’s available either as a consumer unit or, considerably more cheaply, as a Raspberry Pi HAT.

Sensly's air quality monitoring HAT has applications at home and in education

Sensly will be able to detect benzene, carbon monoxide, formaldehyde, nitrogen dioxide, sulphur oxide, ammonia and polycyclic aromatic hydrocarbons; now that it has met its first stretch goal, it will also detect particulate matter such as pollen, smoke and mould spores, and backers will get this useful additional functionality for free. Temperature and humidity sensors are thrown in too. As with the Sensly consumer unit, the HAT version can communicate directly with your smartphone, giving you push notifications of high levels of pollutants, as well as uploading data for viewing (and, if you want, sharing) via a web browser.

We really like the idea of making a device available as a Raspberry Pi HAT as well as a boxed appliance so that you can hack and customise your own system, and the possibilities of this one are pretty broad. You could connect a camera board, for example, and investigate whether anything in particular happens to nitrogen dioxide levels when lots of Volkswagens are in the vicinity. Several unpleasant constituents of cigarette smoke are detected by Sensly, so you could quantify the effect of cigarettes on your air quality. With the addition of pH sensors, a number of the devices could monitor sulphur oxide levels and rainwater acidity across geographically distant locations over long periods; what patterns might be found in those data? And if I still lived aboard the fine narrowboat I used to own, I could save myself a considerable amount of anxiety by properly logging carbon monoxide levels and finding out how they actually varied with the use of our three cooking and heating stoves.

Narrowboat Roe moored on the Old West at sunset

Converted 1959 British Waterways River Class freight butty Roe moored on the Old West at sunset, and a heady quality of nostalgia. But there’s no point my hanging around here reminiscing; the past, as Elsa put it with memorable force, is in the past.

The team behind Sensly might be onto something when they argue, as they did in their winning pitch to Pitch@Palace On Tour recently, that making air quality more personal and tangible with a low-cost sensor system could motivate people to take action, and all sorts of recent news stories suggest that there is scope for paying a bit more attention to what we’re breathing. As a single example, evidence to the UK government’s consultation on air quality plans, released a week and a half ago, revealed that nitrogen dioxide exposure alone is causing an estimated 23,500 early deaths in this country each year.

Early-bird backers of Sensly’s Raspberry Pi HAT will get a device that shows them local levels of this and all kinds of other substances of interest for £25, but you’ll have to move quickly; the campaign closes this Saturday.


Jeff Greer avatar

I have some background in environmental testing. It would be nice to know the sensor technology used for this device. If it is just a solid state CMOS sensor, nothing new here. I visited their website, no details. I did subscribe to their mailing list. I hope there is something new here.


Tony avatar

Hi Jeff,
I found this on their Kickstarter FAQ’s, don’t know if it helps:
“We use electrochemical sensors for detecting gases, which are based on a tin dioxide semiconductor. When gas enters the sensor, depending on the gas it is either reduced or oxidised. Using the electrical signal from this process we can identify the level of a gas or group of gases in the atmosphere. The semiconductor layer is doped with various elements to alter is sensitivity to various gases. Due the noisy nature of electrochemical cells we tend to only get readings in parts per million.”

ramasubramanian avatar

sir/mam, i want to details about the SENSLY: AN AIR QUALITY MONITORING HAT project plz sent to my mailing address [email protected]

Brian Li avatar

The Tricorder Project!

Andy H avatar

Looks interesting and I was about to bite – but then I noticed the timescale.
I’ve been bitten too often on KS to go for something with nearly a year’s lead time.

Altitude Tech Ltd avatar

Hi Andy,

Totally understand the hesitation to back Sensly due to the 1-year delivery date. We set that date as a buffer, but now that development is going extremely well we should be able to deliver the Sensly HAT in significantly less time.

Moo avatar

Is there a version that automatically adjusts when a VW diesel car is detected?

Boris avatar

Give that man a cookie!

Akshat Parasher avatar

Really liked this project , this is what I really want to do on my own ….
Mam please send all details of this project to my email [removed]
One of the best project I have ever seen !!
Thanks in advance :D

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