We live in an era of high pacing world, where its very difficult to have control over  everything with the help of human supervision. Since then, there’s been  the constant effort by the engineers and scientists to minimize the burden of having control over domestic workloads; which progressively lead to the development of the field known as Internet of Things; abbreviated as IOT.

— Monitoring and controlling peripherals, devices, sensors and nodes remotely saves time and resources. Many of us have gardens in front or back of our houses. Suitable amount of water and normal temperature is crucial for plants beneficial growth. Its our utmost desire to water our plants in garden when needed.

–The intent here is to monitor the garden temperature and soil moisture level. If the water content in soil is less than needed by the plants an autonomous switch will start the water pump for watering the plants. User can monitor and control the garden now by his cell phone, desktop and laptop.

–The aim of here is to build affordable solution to the above mentioned problem.

Components required

Sensors play a major role in development of this project. Here two particular  types of sensors are used:

DHT-11 Temperature and humidity sensor. 

Arduino soil and moisture level sensor.

DHT-11 is a one wire digital temperature and humidity sensor. It can measure temperature from 0 degree Celsius to 50 degree Celsius with 2% margin of error. It can measure humidity levels between 20 to 80% with 5% margin of error. It requires 3 to 5 volts for its operation.

Soil/water/rain sensor is popular water moisture sensor among diy circuit makers. It has two legs coated with nickel or copper. Normally the resistance between the legs is high and it decreases when we insert the legs in ground. The moisture in soil made a path between legs and starts conducting power. The strength of conduction depends on the moisture level or water content in soil. More water means more conduction. The output of the soil moisture sensor is analog and digital. Analog output depicts the ratio of water in soil. Where as digital output shows that the moisture water content reached or increased the desired level. Rain/water sensor works on 3.3 to 5 volts.

      *The above pictures are of the sensors used. From left to right: DHT-11,soil moisture.   

Node MCU esp8266-12e WiFi module.

Also, there’s need for the system to process these inputs from the sensors and also to update them to the server, all of which is taken care of using a simplistic  microcontroller which also has an embedded wifi module. Node MCU is system which does all of the above mentioned tasks.

 Block diagram:

Circuit Diagram:

Connections are to be made as shown,

The soil moisture sensor comes with two variations, one with the three pin configured module while the other with 4 pin configuration .Here the 4 pin module is used where the speciality is it has both analog and the digital pin outs. Usually either one of those are used, here since we are combining its actions along with the other sensor we use both the pinouts.


After the connections are made according to the pin diagram shown above ,the server has to be setup along with the database sever for integrating of the wifi module and the firebase. The wifi module has to be programmed to be connected to the stable network. Now the secret key of the firebase has to be engraved to the wifi module so that the  periodic information is updated.

 The main advantage here is that the secret key remains universal for the account, no matter if its being monitored on the different devices simultaneously, but under the same account.

Once the connections are being set, its now time to test it. The updation period  is rapid for the written code, it can be changed accordingly. The surveillance period is rigorous the entire time the whole setup is charged.

The whole setup works with the normal 9v battery, which powers both the sensors  and the node mcu as well. Additional power can be attached if needed.


Integrated working of the different inter network connections.

Working of the database servers in accordance with the local network.

Output voltage regulation based on the system requirement.

Working range with periodic updation over several trials. Vulnerability of the device information, and thereby methods of protecting it accordingly.

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