The whole Mushrooms' Paradise blog
This post is about the vegetable part of the farm. This part doesn’t use anything from Element14 kit, but I thought it could be a nice add-on to mushrooms farm.
Components
ESP32
Vegetable part of the farm will be controlled by ESP32. I chose ESP32 because I will need analog pins for sensors and RPI does not have it. Now, after reading other blogs I see that it is possible to install both Enviro Hat and Automation HAT on the same PI so in this case I will get 4 analog pins. But even so it looks like I will not have enough free GPIO pins to control all my components.
DIY Irrigation kit
While looking for soil moisture sensors I found a DIY irrigation kit here and it includes 4 pumps, 4 5v relays, flexible tubes and 4 capacitive soil moisture sensors.
The main reason I got it is capacitive soil moisture sensors. The rest is just a nice bonus.
Soil moisture sensors.
There are 2 main types of soil moisture sensors - capacitive and resistive. Description of both can be found here Soil Moisture Sensor for Arduino, ESP8266 and ESP32 After reading the description my choice is capacitive sensors. The biggest reason is that the resistive sensor works only several days and then becomes unreliable due to corrosion. I will need reliable sensors working for a while. The problem with capacitive sensors is that specifications say they need to be powered at 5v. However I powered the test sensor with 3.3v, soil moisture values were really weird, out of range, but with some testing they could be mapped to desired soil moisture percentage.
Capacitive soil moisture sensor
Water pumps
Description of several types of low voltage mini water pumps can be found here Automatic plant watering systems for Arduino - ThePlantBot.com
The best pump for this project would be the peristaltic pump. But I decided to use the one that came with the kit - 5v mini water pump. They are the cheapest and not the best but they will do the job for now. More information about them can be found here
Best 5V arduino water pumps - ThePlantBot.com.
My water pump
Specs:
- Voltage: 5 V
- Operating current: 100-200mA
- Load power: 0,4-1,5 W
- Water flow: 80-120L/H
- Continuous working life: 500 hours
4 meters of tubing that fits these water pumps precisely were also included.
3.3v Relays
I don’t think I can use 5v relays that came with this kit. I will use the same 3.3v relays that I used for mushrooms part of the farm. They have absolutely no specifications provided but they work with PI so I hope they will work with ESP32 as well.
And the problem
The problem is after playing with this irrigation kit and testing sensors I switched to finish RPI components and enclosure assembly. And now I cannot find the kit.
I ordered a new kit but there is no way I can finish this part of the farm by January 5. However I will work on it after the new kit arrives and will post the results in this blog.