This latest version of the board allows you to choose what you want to monitor in the tower. This board has been designed to be modular to suit your needs.

We will look at each module one by one:

Main module :

This module is mandatory. It is the brain of the tower with the ESP32 and it is the one that allows the power supply of the board, the generation of the fog and the filling of the small tank thanks to the pump.

EC module:

This module allows you to know the mineral concentration of the solution. Optional module.

pH module:

This module allows the acidity of the solution to be known, given that a pH between 5.5 and 6.5 is desired. This module is optional.

Temperature module:

It provides information on the temperature of the ambient air, the root chamber and the water in the main tank. It also compensates for pH and EC sensor values that are correlated to the water temperature. This module is optional. You can also use a single sensor depending on your needs.

Conclusion:

The electronics of the tower cost 61.4€ with all the modules but it works with only the main module which costs 36.4€. You can reduce the price by recycling an old laptop 18-20V charger.

This PCB can also control 2 additional pumps to adjust the pH and nutrient concentration. But I haven't implemented this in the code yet.

You can find the gerbers in the project files. (gerber_PCB_final)

Schematic: