How to measure Air Quality in real-time! Easily visualise and save data (SGP40) |

In this video I show you exactly how you can measure the quality of the air using the SGP40 sensor coupled with the DHT11. We use the DHT11 sensor to obtain the humidity and temperature, since the quality of the air changes with the humidity and temperature. The SGP40 gives us the quality of the air in terms of the raw resistance. So we use a calculation (from the SGP40 creators) to calculate what is called Volatile Organic Compound (VOC) index, which is what is actually used to measure the quality of the air. I use the ESP32 as the micro-controller, but you can use any micro-controller with WiFi, for example, the ESP8266 will works just fine.
Not only do I show you how to setup everything, but also how to visualise all the sensor data including the VOC index in real time using charts in the web browser, save the data to the cloud (GitHub) so you can have the data as a record, or use the data later for analysis or anything else you want. I also perform tests that you can do, to ensure all the senors are working properly and giving reliable results.
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Links mentioned in the video:
GitHub repo:
github.com/ProjectsWithRed/vo...
SPIFFS for ESP32:
github.com/me-no-dev/arduino-...
SPIFFS for ESP8266:
github.com/esp8266/arduino-es...
AsyncTCP:
github.com/me-no-dev/AsyncTCP
ESPAsyncWebServer:
github.com/me-no-dev/ESPAsync...
Great tutorial on how to install the libraries:
• How to Create a Web Se...

[@YunJang]

Really appreciate the video. It's allowing me to get my feet wet in the Arduino space. In addition to VOC readings, have you by chance integrated or updated this design with a PMSA300I to get PM readings as well? I know that it most likely won't capture ultrafine particles emit into the air from a 3D printer but figured it'd be a nice to have for generally capturing any additional particle emissions and have a clean interface to read from like the way you're displaying data here.

[@ProjectsWithRed]

That's great to hear! Unfortunately I have not made a version that integrates the PMSA300I, however, if you go over the code you will be able to easily add more sensors just by slighly updating the code.

[@YunJang]

@@ProjectsWithRed I received my sensors from Adafruit earlier today and was able to integrate everything using similar code. As expected, the PM sensor wasn't able to pick up much but the VOC sensor was definitely able to pick up enough change even for PLA filament. Thanks again for the video, it's been quite fun messing with the ESP32 and getting metrics from it!

[@ProjectsWithRed]

@@YunJang Good stuff, that's great to hear! I am glad I could help!

[@Metrowhite]

If there is formaldehyde in the air, will the VOC value of this sensor increase?

[@ProjectsWithRed]

I am not sure, I don't have too much experience with this sensor, but I am sure you can find out in the official sensor page here www.sensirion.com/en/environmental-sensors/gas-sensors/sgp40/.
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