Please note that for the VOC sensor we are only reading raw data from this sensor, not ppm or ppb values. Of course, in order to fully understand how it works you need to learn and know how each sensor works with their libraries, as well as how the Nextion display works. Overall, that’s how the program of this Arduino air quality monitor works. If we press the hotstop on the waveform we can see in the Event section that it sends us back to “page 0”. On top of the waveform, as well as the numbers on the main screen, you can notice we have like transparent objects, called “Hotstops” in the Nextion editor, and they are act as buttons. The hours and the Y-axis values also get their values from the Arduino. Now if we try to connect everything together, we will get quite a mess because of the many connections. See also: The 8 Best Arduino Starter Kits The whole device is powered with 5V through a Mini USB connector.

We are also using a Real Time Clock module for keeping track of the time when storing the sensors values, and it uses the I2C communication. The two transistors are used for activating the sensors heaters. For reading the VOC and the Ozone sensors we use analog inputs of the Arduino, while the DHT22 temperature and humidity sensor uses a digital pin for that purpose. The CO2 sensor and the Nextion display also use serial communication. It works at 5V, but the receive RX logic level works at 3.3v, so therefore we need a voltage divider for it. The PM2.5 sensor communicates with the Arduino through a serial interface.

As an Amazon Associate I earn from qualifying purchases.Ĭorrect resistors values: R1 = 1K, R2 = 2K, R6=100K or 1M, R7=1K Capacitors values: 0.1uF ceramic and 10uF electrolyticĭisclosure: These are affiliate links.2 Positions switch ………………………… Amazon / Banggood / AliExpress.Distance / Spacer Nuts M3 …………… Amazon / Banggood / AliExpress.You can get the components needed for this Arduino air quality monitor from the links below:

Arduino altium schematic