Yesterday I put together a street air monitoring station, the data from which is already displayed in the worldwide monitoring systems.
The station measures the concentration of fine dust PM2.5 and PM10 in the air, measures temperature, humidity and pressure and transmits this information to the servers of various public monitoring systems. PM2.5 and PM10 are good indicators of total air pollution and can be track the overall level of air pollution from car exhaust, forest fires, combustion garbage. It uses the good SDS011 laser dust sensor, which gives very accurate results. The cost of all components of the station does not exceed 2000 rubles.
It all started with an announcement in the regional group "Let's make Sviblovo cheerful again". Usually there are lectures on travel or master classes on making something like Christmas tree decorations, and then a master class on assembling air quality monitoring stations was announced. Everyone was invited to buy the necessary components on Aliexpress in advance and come with them.
I got interested, bought everything I needed, and in the morning I soldered the entire structure, although it could be assembled without the help of a soldering iron.
All components fit into a conventional junction box. The tube, through which air from the street is sucked in, is brought out. The temperature, humidity and pressure sensor board is inserted into the same tube through the cut, so that the sensor itself is inside the tube.
At the bottom of the case, you must make a hole through which air will escape.
The station can be glued to the window with double-sided tape, and the flat USB cable, through which the station is powered, fits perfectly in the window flap.
It was a big surprise for me that people who were completely unfamiliar with electronics spent their money, bought components and came to assemble their stations.
Everyone diligently cut the connectors, rearranged the contacts and connected them to the components.
And they did it. Yesterday seven stations were assembled, today there are already three.
Data is displayed on German Sensor Comunity website and in Russian Public monitoring of air quality in Russia.
There are now about eighty monitoring stations in Moscow (there are already more than 10 thousand in the world). On a German website, air quality is shown in color (the greener the hexagon, the better).
On the Russian site, the values of the selected parameter are immediately visible.
This is how the local display of measurement results looks like.
In order to assemble the same station, you will need the following:
1. Dust sensor Nova PM SDS011 for $ 17.71;
2. Microcomputer NodeMcu V3 (choose CH340) for $ 2.03;
3. Temperature, humidity, pressure sensor BME280 for $ 2.07;
The first three positions are from one seller, you need to choose Aliexpress Standard Shipping and you can order fast delivery to Pyaterochka stores (pickup).
4. Tube (choose 6x8 mm) for $ 1.17;
5. Junction box (in any store of electrical goods or household goods) - 50 rubles;
6. USB charging with a current of at least 500 mA.
Additionally, you may need:
6. Connecting wires Dupont (choose F-F) for $ 0.58;
7. Flat USB-MicoUSB cable (choose the desired length 2 or 3 m) for $ 1.85-2.32.
Detailed instructions for connecting, flashing, registering in the system are here.
Why do you need all this, you ask? Primarily for the public good. When severe air pollution occurs somewhere, government services sometimes simply turn off their monitoring stations and information can only be obtained from enthusiastic stations. Besides, I wonder what kind of air I have outside my window. And at the same time it is also an accurate personal thermometer, hygrometer and barometer.
The screen in the title photo is optional. In a device hanging outside the window, it is not needed. I want to make a separate monitor with a large TFT screen on the Arduino, which will take data from the page formed by the station and show large numbers.
I also want to make a second station of the same and hang it at the dacha, since the Internet is still there (for video surveillance).
P.S. Thanks to Irina Evdokimova, who organized this whole movement, and to the Open Public Project breathe.moscow for conducting a master class.
© 2020, Alexey Nadezhin
The main topic of my blog is technology in human life. I write reviews, share experiences, talk about all sorts of interesting things. My second project - lamptest.ru. I test LED bulbs and help figure out which ones are good and which are not so good.