Like the previous PCB, you can choose the modules you want. This board has been designed to be modular to suit your needs.

Update :

- New alternating current circuit for disks and current control circuit (log)

- Power supply voltage changeover from 18V to 12V

- The 5V problem seen in this log has been corrected by adding a second CN3903 3A.

- Change of layout to avoid mixing voltages

- Component optimization

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 49,5€ with all the modules but it works with only the main module which costs 28,1€. You can reduce the price by recycling an old 12V 3A charger.

You can find the gerbers in the project files. (PCB_V2)

Schematic: