This instructable is a step by step guide,
showing you how you could make your own in-house air quality station. The following data is collected with this setup.
· Temperature (in °C)
· Humidity in (in %)
· CO2 (in ppm)
· TVOC (in ppb).
TVOC, otherwise known as Total Volatile Organic Compounds, is a collection of organic chemicals that have a high vapor pressure at ordinary room temperature.
MATERIALS(more information in BOM)
· Raspberry pi 3
· 240-OHM Resistor
· Female - Female wires
· Female - Male wires
· Male - Male wires
Step 1: Creating a Fritzing Schema
The DHT11 is not the most accurate sensor, but it will definitely to the job. In case you want a more accurate humidity/temperature sensor, you can use the DHT22
In order to utilize the CSS811 there are some extra configurations required which I won’t explain further. You can find everything here: Adafruit CSS81
The DHT11 is a onewire component that doesn’t actually work as a onewire component. It’s a mess if you want to program it yourself, so I highly recommend using a library: Adafruit DHT**
Step 2: Making the Database
Utilizing the image above, you should be able to create your own database.
I hosted this database on my Rasberry pi using MariaDB
Step 3: Building the Temporary Setup
I made this setup to test the sensors before I soldered it all togheter.
Step 4: Making a Responsive Site
In order to manage the collected data, I made a site that neatly displays everything in graphs.
Step 5: Wrapping Up!
Once you have finished all the steps succesfully,
you can start the final process, which is covering up the components in a protective case. In order to do so I highly recommend you to solder your components together so they can’t be disconnected by accident.
In the images above you can see some steps I have taken to make my case.
First I soldered everything together, then I could put every component into place and finally I gave my components some extra cover so that they wouldn’t be affected by the heat of the raspberry pi.
I decided to mount my LCD completely outside of the box simply because it produced too much heat (about 5 °C above the normal temperature level on average).
Close mechanism: Magnets