Smart Greenhouse Sensors



Introduction: Smart Greenhouse Sensors

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Hello everyone,

Today I will show you my little project that I built for couple of days.

This set is made of 4 (four) different sensors and I think that every greenhouse owner should have it, and it should make his life a bit easier.

LCD sensors output is in Bosnian, but I will translate it for you in the code and here. :)

Total cost of this project: $16 or €13,5 (does not include tools and you can go cheaper if you salvage some parts).

I will post items that I bought from Aliexpress, and they are the cheapest and best quality ones that you can find on Aliexpress.


I am not responsible if you hurt yourself or others around you!

Step 1: Gathering Items and Tools

For this project you will need:

Arduino board (I used "Nano"):

LCD I2C screen:

Photoresistor for light sensor:

Soil moisture sensor:

DHT11 temperature and humidity sensor:

Mini Solar panel

3.7V battery (best to use one from an old phone or LiPo because of space)

TP4056 battery charge/dishcharge protection:

Boost buck converter 3.7V to 5V (manually fixed):


Tactile switch for reset (optional):

Switch (you can use any, I used these):

Heatshrink tubing, duct tape, wire and installation box you can probably buy in your local store.

Step 2: Schematics

I made this detailed schematics for you, I hope that it's not too complicated, but I will write all connections.

If you can't see, I uploaded my .fzz Fritzing schematics or you can download my high resolution schema:

- I2C LCD screen

SDA --- Arduino A4

SCL --- Arduino A5

VCC --- Arduino 5V

GND --- Arduino GND

- DHT11/DHT22 temperature and humidity sensor

From left to right

First pin --- 5V

Second pin --- D4

Third pin --- nothing

Fourth pin --- GND

- Soil moisture sensor

VCC --- Arduino 5V

GND --- Arduino GND

D0 --- nothing

A0 --- Arduino A1

(+ and -) --- probe (polarity doesn't matter)

- 6V 1W solar panel

Positive wire (+) --- TP4056 INPUT (+) (it's next to Micro USB port)

Negative wire (-) --- TP4056 INPUT (-) (same)

- 3.7V rechargable battery (don't make a mistake here)

Positive wire (+) --- TP4056 (B+)

Negative wire (-) --- TP4056 (B-)

- Boost buck converter

(VIN+) --- TP4056 (OUT+)

(VIN-) --- TP4056(OUT-)

(VOUT+) --- Arduino VIN

(VOUT-) --- Arduino GND

-For light sensor please see schematics-

Step 3: Uploading the Code to Arduino

You will need to download some libraries:

DHT sensor library:

LCD I2C library:


Copy them to: ...\Arduino\libraries

And upload the code to Arduino.

Step 4: Connecting Everything

Be sure to use short wire and good quality solder.

For the box part, I uploaded a picture which shows you how to connect signal LEDs.

Desolder small SMD LEDs from boost converter and TP4056 module, glue your own LEDs to box and solder them to modules.

Reset button is optional, connect one end of tactile switch to GND and the other to RST pin on Arduino.

Be sure to turn the photoresistor to the sky.

Best box to use is the installation box for the electrical cables. They can withstand high temperatures and will protect electronics in it. (You can use hot glue to glue everything and it will not even get warm in this box)

Measure the LCD screen and cut the installation box to fit the LCD screen. Then glue it tightly with hot glue or epoxy.

Glue the solar panel with syntelan or epoxy (don't use hot glue here because it will melt on sun) on the top and take the cables from it through the box and into the box.

Step 5: Done!

Place it somewhere in your greenhouse. The best place to place it is somewhere in the middle of the greenhouse.

If you look closely at the bottom of wooden pole you can see that I made a coil of wire that is connected to the soil moisture sensor, so I can unwind it and measure the moisture anywhere in the greenhouse.

Translation of video:

Temperatura - temperature

Vlaznost zraka - humidity

Vlaznost tla - Soil moisture

Svjetlost - Light

Feel free to ask any questions.

Have a nice day :D

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