I is a simple system, using Arduino to automate the irrigation and watering of small potted plants or crops.
This system does the control of soil moisture, doing indications via LEDs and in case of dry soil emitting a alarm beep. In case of dry soil it will activate the irrigation system pumping water for watering plants.
The system uses a LCD display to notify all actions that are taking place and a real time clock.
The Theory (from Wikipedia):
Water content or moisture content is the quantity of water contained in a material, such as soil (called soil moisture), rock, ceramics, fruit, or wood. Water content is used in a wide range of scientific and technical areas, and is expressed as a ratio, which can range from 0 (completely dry) to the value of the materials' porosity at saturation. It can be given on a volumetric or mass (gravimetric) basis.
Volumetric water content, θ, is defined mathematically as:

where  is the volume of water and  is the total volume (that is soil volume + water volume + air space).
Gravimetric water content[1] is expressed by mass (weight) as follows:

where  is the mass of water and  is the bulk mass. The bulk mass is taken as the total mass, except for geotechnical and soil science applications where oven-dried soil (, see the diagram) is conventionally used as .
To convert gravimetric water content to volumetric water, multiply the gravimetric water content by the bulk specific gravity of the material.
In soil mechanics and petroleum engineering, the term water saturation or degree of saturation,  is used, defined as

where  is the porosity and  is the volume of void or pore space. Values of Sw can range from 0 (dry) to 1 (saturated). In reality, Sw never reaches 0 or 1 - these are idealizations for engineering use.
The normalized water content, , (also called effective saturation or ) is a dimensionless value defined by van Genuchten[2] as:

where  is the volumetric water content;  is the residual water content, defined as the water content for which the gradient  becomes zero; and,  is the saturated water content, which is equivalent to porosity, .

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baltazar163 days ago



rcatic5 days ago

can you please send me complete project with codes and libraries to

thank you

BIGDOG1971 (author)  rcatic4 days ago
As you have requested, I sent the code and libraries for you.
Check your email, please.
baltazar166 days ago


nice project!

can you please send me complete project with codes and libraries to

BIGDOG1971 (author)  baltazar164 days ago
Sent, check your email, please.
carloscabd29 days ago

hi Sir, can I get the complete project details and codes?

BIGDOG1971 (author)  carloscabd25 days ago
Hi carloscabd

For sure you can get the project details and codes.

Send an email to and request the code.
ššnac1 month ago

can you please send me complete project with codes and libraries to
thank you

BIGDOG1971 (author)  ššnac25 days ago
It was sent to your email

Feel free to send me your questions.
bkapoor1 month ago

Sir can you please sent me this watering project including all the codes . Sir I really need this for my college project. This is my email id Thank you sir in advance

BIGDOG1971 (author)  bkapoor25 days ago
It was sent to your email

Feel free to send me your questions.
nurrai1 month ago

hi sir ! can you please sent me this watering system project . including the codings . i need this for my integrated design project subject . here is my email . i hope you can send it to me . thanks for your cooperation ! :)

BIGDOG1971 (author)  nurrai1 month ago
Hi Nurrai

I will send the requested files on your email.

Godday sir. Can you plese sent me your whole project, because i have trubles with finding libraries. I don't know where too look anymore. my mail is

Thank you for all your effort

charlonharris2 months ago

goodday acct can't be opened.could you please resend the email that you have sent regarding automatic watering system to my new acct. you and godbless.

i need the full study as soon as possible.. thank you for your kind consideration ..

BIGDOG1971 (author)  charlonharris1 month ago
The code and Libraries was sent.
vacosta iii2 months ago

sir BIGDOG1971, good day. can i use this project as reference for my school project? can you send me the full file of this? it's for our instrumentation subject. my email address is thank you so much if you will :)

charlonharris2 months ago

good day sir..can you email me the full study of this watering system?i just need this for my project..thankyou and have a nice's my email

BIGDOG1971 (author)  charlonharris2 months ago
Hi Charlonharris

For sure!
nodoubtman2 months ago

Are you watering your plants everytime it's dry?

How often are you watering your plants?


BIGDOG1971 (author)  nodoubtman2 months ago
Hi nodoubtman,

Are you watering your plants everytime it's dry?
Yes, the sensor tells me when the soil moisture is considered dry and in this way I know whether I need to watering the plants or not.
But depends on of the kind of plant you are watering too.

How often are you watering your plants?
It depends of the air humidity and others factors... maybe twice or three times each five days, on my region (Brazil southeastern) we have a wet climate.

thanks for the comments.

Best Regards

Marcelo Moraes
asltan3 months ago
I get error how i can solve it
error in RTC
BIGDOG1971 (author)  asltan3 months ago

Send me an email with a screenshot of the error.
dsrtruealg5 months ago
good day. may i ask how did you come up with these values ? Soggy soil - moisture between 0 and 500;
- Wet soil - moisture between 500 and 800;
- Dry soil - moisture between 800-1023;
did you find any data sheet? thank you.
BIGDOG1971 (author)  dsrtruealg5 months ago
Have a nice day.
This values are only to the simulation.
You will need to doing some field tests and and analyze the range to the soggy soil, wet soil and dry soil.
There is not any datasheet for this scope, only field adjusts.

mizane756 months ago
sorry sir..but why ur coding does not working for arduino programmer 1.0.5. I have try it for many times but it still have an error.
BIGDOG1971 (author)  mizane756 months ago

The code is working properly for the Arduino IDE version 1.0.5
Send me an email with the error message and I will analyze.

ok sir i have send it to u...i hope u can give me a feedback
abibi16 months ago
That was informative, thanks!
nodoubtman6 months ago
Thank you so much! :)
boonkue6 months ago
very good ideas
Nice project! Voted!

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