This step is only required if you'd like to edit the PCB files provided here.

The Gerber file provided here is ready to upload

While this project encourages modularity, some components like resistors and capacitors are soldered directly to the PCB

Plug each module/sensor in its designated spot on the PCB

Have a look at the Arduino file provided here. Some variables will need to be updated to suit your needs

Once ready, just upload it to the ESP32

Use the provided STL files (main body and lid) to 3D print the case

In order to avoid yellowing from the sun and to better protect the case from the elements, you may want to give it a few coats of white paint. I used just regular spray paint

I used some bug net that if usually used for doors and windows but you can use other materials too. This is to avoid getting dust and insects inside the sensors

Install the solar panel and make sure to use a generous amount of sealant underneath it to prevent water from dripping inside the case

Move everything inside the box and adjust the trimpots to calibrate the measurements.

Precise calibration wihout a known concentration of each gas is not possible, however the datasheet of the sensor recommends to calibrate the output to 2.5V and you should adjust the trimpots to obtain a value of 2.5V in a day with no pollution (or somewhere in a forest). That will be the reference