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Final PCB : Cost and Modularity

A project log for UltraTower

Grow vegetables with ultraponics tower

J GleyzesJ Gleyzes 10/01/2022 at 08:400 Comments

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.

ComponentQuantityCostLink
PCB11.6€
Lolin 32 Lite12.85€Aliexpress
CN3903 5V 3A 
DC-DC Step down
10.49€Aliexpress
Capacitor 400V104J  20.12€
TN0604N3-G11€
DC Charger connector 10.2€
18-20 V Charger  112€
330uH coil20.32€
100 ohm resistor20.025€
10K ohm resistor20.025€
FQB19N20LTM   21.81€Onsemi
Mini JST 2.0 PH  30.088€
Usb Pump connector 10.3€
5V Pump110€Aliexpress
108kHz Disk22€Aliexpress

EC module:

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

ComponentQuantityCost
330 ohm resistor20.025€
22nF capacitor10.013€
Mini JST 2.0 PH  10.088€
EC probe11€

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.

ComponentQuantityCostLink
MCP648710.4€Microchip
TC766010.99€Microchip
BNC connector10.73€Aliexpress
pH probe111€
200k ohm resistor20.025€
10k ohm resistor20.025€
22K ohm resistor10.025€
82k ohm resistor10.025€
4.7k ohm resistor10.025€
1uF capacitor20.013€
10uF capacitor20.013€

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.

ComponentQuantityCost
DHT2212.46€
DS182022€
10k ohm resistor10.025€
4.7k ohm resistor10.025€

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:

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