Water Saving Simple & Low Cost Automatic Plant Watering System

In this instructable I am going to show you how I made a very low cost plant watering system using some very common parts and electronics that will help to keep your plants hydrated all the time. Folowing this instructables you will be able to easily replicate it.

One of the most common problems that every household faces is to water the plant on time. Sometimes you may forget to water your plant, sometimes you are very busy or go outside for your home for several days.

Another problem is most of the time we fails to provide the right amount of water for a plant. Often we provide more water than the required amount and waste the valuable water.

The result of the above two problems is dry plant or wastage of water and I know this is not the right way! So I planed to build something that would keep my plant hydrated all the time with the right amount of water. I checked online for various plant watering gadgets and they all came with some price tag which I think is not for me and not for most of the people in my country and I do beleive there should be an easy way.

So, I did some research and built a watering system for my plant that used some very common and inexpensive electronics but works perfectly. Now I can leave my plants unmaintained for several days.

If you own a plant and are facing the issues like me then I would recommend building this project and don't worry if you are a beginner. I have given step by step instructions with video demonstration to build this. You just need to have some time and have access to a 3D printer.

I used the following easily available components and parts for my project. The electronics used in this project is easily available on almost all local electronics hobby shops.

1. Arduino Nano
2. Arduino Nano I/O Shield (Recommended but not mandatory)
3. Micro Servo SG90 (Metal Gear is recommended)
4. Capacitive Soil Moisture Sensor

Following non-electronics parts are required

1. Saline set

This part is required to flow the water from the water container. I could use other pipe but saline set is easily available in any drug store and very low cost.

A water container is required for storing the water. I used a 5liter water bottle as a water container.

Watering can be done in a regular interval or can be based on the soil moisture. I took the second option and for this moisture sensor is required. So, I made a 3D model for housing the sensor, a micro servo motor and inserting the water pipe. The logic is that, moisture sensor will read the moisture content of the plant pot and based on the moisture content the servo motor will be rotate to block or allow the water flow through the water pipe.

I designed all the 3D file in Tinkercad.com because this is a platform where you can make a 3D design without any training.

I uploded the 3D design files in thingiverse. You can download the file from the link below:

https://www.thingiverse.com/thing:7057009

After 3D printing and collecting all the other parts, the next thing is the assemble the parts. Assembling is very easy and I uploaded a assembly video at step 5. To assemble follow the steps below:

1. Insert the capacitive soil moisture sensor to the base
2. Guide the sensor cable
3. Insert the pully to the servo motor and add the screw.
4. Place the servo motor to the servo slot
5. Attache the servo screws
6. Place the top cover

Inserting the water pipe is also very easy. You just need to push the pipe through the top hole towards the the bottom hole. It will automatically follow the path.

For avoid any soldering I used Arduino Nano I/O shield for connecting servo and the sensor. We can use upto 8 sensor units for 8 plants using a single nano i/o shield. We need 8 analog pins for eight sensors and eight digital pins for attaching 8 servo motors. For each sensor unit we can use any analog port (A0 to A7) and any digital port. You just need to modify the code accordingly.

I used A0 and D8 for first sensor using and A1 and D9 for second sensor unit.

The Arduino code for the system is below.

This video will help you to assemble the sensor, servo motor and the 3D printed parts very easily. Watch the video carefully and assemble accordingly.

After assembling, attache the servo to D8 port and observe the motor is working.

After preparing all the sensor units I installed the system to my plant. I used two sensor units for my two plant. I placed the plant in my balcony. So, I fixed the arduino unit to my balcony grill with zip tie. Then, I inserted one sensor unit to each plant pot.

Finally, I connected the sensor cable and servo cable to the corresponding port of the nano io shiled as mention in the previous step.

The water pot is placed at a hight so that water fall to the plant pot due to gravity. As, I used a plastic water bottle, I made two small holes for inserting two pipes. Every saline set has a spike and I inserted that spike through the hole. To avoid any water leakage, I used some hot glue to tightly fixed the spike to the hole and fill any small gap.

I filled the water bottle and connect the power source to the nano io shield. Power can be provided through the USB programming port or the DC barrel jack. I used the first option.

The system is finally ready to serve me.