Having pursued a career in data and analytics, I’ve been thinking recently that it would be fun to take on some kind of data logging project at home. In light of that, I’ve been looking at a few sensors available for the Raspberry Pi that I could use.
Probably one of the most straight forward measurements would be temperature. With just a temperature sensor and the right resistor, the Pi can measure temperature and capture it through the terminal window. With that possibility, it is then very straight forward to log it in an ASCII file, or even drop it into a SQL database. Using a python module such as matplotlib the system could create a constantly updating graph that could be shared to a web server, having a very straight forward sensor, the results accessible via a browser.
The Sense Hat
A more refined piece of hardware already exists, and this is the Sense HAT. If I understand this rightly, the sense hat sits on the Raspberry Pi board directly over the GPIO pins. As well as a temperature sensor, it also senses air pressure and humidity, and it even has a built-in accelerometer. It looks like a very capable board for a fantastic price. It was also used recently for the Astro Pi project by astronaut Tim Peake. It looks like a very straight forward, easy to set up means for learning data logging.
Weather and Air Quality
I also learned that weather is an interesting option for Raspberry Pi data logging. Recently, a set of schools were distributed with Pi based weather monitoring kits. Unfortunately these never made general production, however there are several guides available for sourcing your own components and making your own.
Looking at the weather stations got me looking at something I’m more interested in: air quality. In recent years I have thought more and more about air quality. In 2013 I spent Christmas in Salt Lake City, Utah. While I was there, I saw something I’d never seen before: visible smog. I would say Utah is no more or less car loving than the rest of the USA, but a few geographical features of the landscape make it prone to this inversion. The area around SLC is in the Salt Lake basin. It is surrounded by mountains and little or no weather, so the pollution just gathers in the bottom of the valley until a weather front blows it away. Anyway, I digress. I never realised how real it could be.
Now, I live in Leeds which very seldom has smog, if ever. Even so, British cities have been criticized for their poor air quality recently, so it would be interesting to measure air quality around here and get some of my own statistics on what’s going on.
There looks to be a few sensors available. Most interestingly is the Sensly HAT, which senses particulate matter, carbon monoxide, nitrogen oxides and the other poisonous gasses in the air. It’s still in development with a hopeful release date of September 2016 and is being developed by Altitude Technology with the support of a number of organisations. I like the look of this product; it carries the backing of the University of the West of England so it should be well refined and produce some good data. I’ll be interested to keep and eye on its development.
There’s a few more obscure sensors already available for the different measures, such as the SEEED STUDIO 101020078 Grove Air Quality sensor. These look a little trickier to work with, and although I gather they could work, an electronics novice like me might struggle.
So there we have it, a set of Raspberry Pi sensors measuring a variety of interesting constructs. I particularly like the Sensly HAT and I hope it gets into production soon. It would be most excellent to have a crowd sourced air quality measuring scheme to support air quality research. It would also be an awesome DIY data logging/analytics project too.