Community vote: Community Choice Poll - In the Air Challenge
Although invisible, air is the most important in our lives. We can survive days without food and water, but only minutes without breathing. So we should consider air quality seriously.
It was a great pleasure to participate In-the-Air-Challenge organized by Element 14 and supporting companies.
Compared to the previous roadtests this was a difficult contest as three kinds of microcontroller development boards were supplied.
Challenge was intended towards programming of internet connectivity of microcontrollers, and Farnell shop does not contain large variety of sensors that could be bought.
Blogging appears to be the most efficent way to summarize results online. Element 14 blog is very nice as people can post questions and visitor count is also displayed.
I have built a box that included many cheap sensors: temperature, humidity, light, sound, air pressure, dust sensor from Sharp and electrochemical CO2 sensor. It was assembled for test of air quality in school during classes and showed that it is important to open the window during breaks. Probably graphing data is not so essential and it would be enough to just indicate with LEDs if air is good, normal or poor. Two school students wrote their scientific report in physics about air quality sensing and presented it at school. They got promoted to a regional contest.
Large part of roadtest budget was spent to acquire infrared CO2 detector. That is more precise than electrochemical. I interfaced it to the IoT and measured air quality at office and during meetings. As IoT provider I used Xively, the one that I had learned to use previously. AirVantage seems to be more complicated to get started with.
Dust detector, laser based
In one blog post I demonstrated how to set-up Wi-Fi and webcamera on a Beagle Bone Black and it could be used to take pictures of dust flying through a laser beam. Such pictures could be sent to a server for image processing using for example LabVIEW. It appears that we swim in an ocean of dust of up to 50 particles/cm3 beig equivalent to 50 Million in a m3. For humans most dangerous are particles in the 1...10 um size that get stucked in the capillaries of lungs. Only HEPA rated filters can stop small dust. HEPA filter gets visually dark after a month. It is also nice to be able to measure particulate matter content outside the window in the city and not to depend on data from govermental agencies reporting in the newspaper just the average situation.
Laser-based dust counter that I constructed using recently available high-power blue diode laser makes it more sensitive for detection of smaller dust. This dust counter helps also my university carier as we got presentation about laser particle counter accepted in EuroNanoForum conference that wiill take place in Riga in June 2015. I was contacted by a nanosensor-on-a-chip company Applied Nanodetectors with offer to collaborate in interfacing their sensors to the IoT.
My former Swedish boss Prof. Sune Svanberg, a great expert in optical atmospheridc pollution measurements, was complaining that the sad thing is that one could only measure pollution, but not actually improve the air. So I am happy that this time could improve the air using HEPA filters. I have now an Electrolux anti-alergy-bag on the air inlet of the lab and sliced plastic film sheets covering the door isle and preventing dusty air to come in. Result is 10-fold decrease of dust content in the room.
In summary, here are all the devices built.
We have presented work done at COST EuNetAir workshop in Riga March 26-27, 2015. Presentation is attached.
Students have written their science project about air quality. Their work is attached (in Latvian).