We live in some very exiting times. Sometimes we need to look beyond the news stories and see the glimpses of hope and prosperity. We are moving forward ...
Below is an infographics of some of the issues we face. Issues like world hunger, absolute poverty, illiteracy, child mortality. All of these have been steadily declining. Regarding absolute poverty we have been ahead of UN targets.
As a die-hard engineer it is also a wonderful time. The technological race has picked up some serious steam lately. Electronics and computers are continuously getting smaller, more powerful and cheaper. Even the most trivial household appliance can have million times more power than the computing environment of the entire Apollo project back in the 60's.
When yours truly started with electronics as a hobbyist 45 years ago (give or take) everything was complex. I spent hours and hours redoing and trying to etch my first dual 6502 computer.
Today my son can for basically nothing have software to do proper layout. He can then get a real PCB with feature size undoable in the kitchen, with solder-mask, 0.2 mm drill holes, plated vias and all done for nickel and dimes. He can even have the board mounted and reflowed for maybe 20 USD.
If he needs plastics and metal he can easily get one-offs from a number of manufacturers worldwide. His most recent project is an electric skateboard and the mechanics for the engine and wheel design cost less than 100 USD. Complete and manufactured using CNC in aluminum.
Recently a common project was started by "The OK Lab Stuttgart" which in turn is parent of "Code for Germany" and "Open Knowledge Foundation Germany". The goal to create a really simple and inexpensive measurement station for air quality. For less than 50 USD the station can report these numbers once every second if need be.
There is a Swedish branch of this, located at www.luftdata.se.
Besides gaseous pollutants, the atmosphere can also be polluted by particles. These particles (either in suspension, fluid or in solid state), have a divergent composition and size and are sometimes called aerosols. They are often catalogued as 'floating dust', but are best known as particulate matter (PM).
This floating dust is most often categorized based on their aerodynamic diameter. The aerodynamic diameter of a dust particle is the diameter of a sphere-shaped particle that shows the same behavior in the atmosphere as a dust particle (which does not necessarily have a sphere shape). In the framework of air quality problems, particulate matter is the most important.
Particulate matter such as PM10, PM2.5, PM1 and PM0.1 is defined as the fraction of particles with an aerodynamic diameter smaller than respectively 10, 2.5, 1 and 0.1 µm (for your information: 1 µm = 1 millionth of a meter or 1 thousandth of a millimeter). In comparison, the average diameter of a human hair equals 50-70 µm (see figure below)
Bigger particles, after being emitted into the atmosphere, quickly get taken down by gravity or are washed out by rain. The finer particles can remain in the atmosphere for a longer time (a couple of days to weeks). As such, these finer particles can be transported over longer distances. Another consequence of this longer stay in the atmosphere is the possible alteration of composition and the change of characteristics of the particles because of physicochemical processes.
On luftdaten.info there are instructions for how to build your own PM2.5 and PM10 station. The cost is less than 50 USD and it takes 2-4 hours depending on your skills. There has also been a numerous gatherings with the purpose of building your now station.
Below is the major parts needed. In the middle is the SDS011 sensor. A 25 USD sensor that measures the amount of PM2.5 and PM10 that is sucked through the unit. We also need a MCU with, in this case WiFi. The community choose the nodeMCU with a specific firmware. The tiny part lower right is a combined temperature and humidity sensor. The grey plastic tubes are for casing.
The raw output is a serial stream (from a simple UART at 9600 8N1) every second. 8 bytes + start ($aa) and end ($ab). The values are 2 bytes (low/high) which are µg/m3 times 10.
On the luftendata.info site you can find detailed instructions. Here is my unit ready to rock. It is built from parts without any soldering at all actually. Everything around the building instructions is for super easy assembling so that anybody who wants can be a part of the network.
And here it is mounted outside on my pool-stuff-shed. When it is not freezing as ... outside I will get it a more permanent place. I will also add a BME280 sensor from Bosch for measuring temperature, pressure and humidity. Probably also a cool 3D printed case that looks a bit better.
Finally a snapshot from the web interface running on the nodeMCU. Despite setting the configurations you can also see the latest measurements done.
This is how it looked 9th of March this year in the world and southern Sweden.
This whole network has be built for the last few months and are growing very fast now.
It is obvious that open source and open hardware together with crowdfunding is here to stay. The pioneers was kickstarter.com but there is even here a large diversity in crowdfunding. Not only tech but movies, books and art. Now there is also "Citizen Science". Global projects where everybody can help and support with little cost. I guess SETI@Home was the pioneers here.
With cheap components, the easiness to create global infrastructure and a efficient manufacturing machine around the world.
Boy to be 12 again ...