Learn How to Make a Plant Weather Monitoring System with a Soil Moisture Sensor, a HC05 Bluetooth Module, Arduino Nano and Water Pump

Why Make a Plant Moisture Monitoring Project?

In today’s busy world where we’re hard-pressed to find the time to relax, it becomes difficult for most of us to water our plants on time. So there are new technologies that are helping in building automated systems resulting in a huge reduction of human work done. Watering is a crucial factor in gardening and sometimes, problems occur if not well regulated due to overwatering or under watering.

Objectives of this Plant Monitoring Project:

The main objective of this Do it Yourself project is to design and implement an IoT (Internet of things) based smart plant monitoring system using NodeMCU (ESP8266).

  • The project’s aim is to detect the dryness in soil using moisture sensor and provide water to the plants appropriately. This project helps to maintain the plants quite easily.

  • As there is no unnecessary usage of water, a lot of water is saved from being wasted.

  • We are using soil moisture sensor which provides us the moisture content through the Blynk app and accordingly we get notification when the pump should be turned on/off. This saves a lot time for us. This also gives much needed rest to us, as we don’t have to go water the plant manually.

Components required for this project:

The complete kit can be purchased at Soil Monitoring Kit

  1. NodeMCU ESP8266: NodeMCU is an open source IoT platform. It includes firmware which runs on the ESP8266 Wi-Fi SoC from Expressive Systems, and hardware which is based on the ESP-12E module.
    NodeMCU ESP8266
    Buy it here: ESP8266 Node MCU 

  2. Soil Moisture Sensor Module: This soil moisture sensor module is used to detect the moisture of the soil. It measures the volumetric content of water inside the soil and gives us the moisture level as output. The module has both digital and analog outputs and a potentiometer to adjust the threshold level. The relation between the measured property and soil moisture must be calibrated and may vary depending on environmental factors such as soil type, temperature, or electric conductivity. Reflected microwave radiation is affected by the soil moisture and is used for remote sensing in hydrology and agriculture. Portable probe instruments can be used by farmers or gardeners.
    Soil Moisture Sensor Module

    Buy it here: Soil Moisture Sensor Module 

  3. 3-6V Mini water pump submersible: It is extremely simple and easy to use. Just immerse the pump in water, connect a suitable pipe to the outlet and power the motor with 3-6V to start pumping water.

    3-6V Mini water pump submersible

    Buy it here: Submersible Mini Water Pump - 3-6V DC 

  4. Relay Module: A power relay module is an electrical switch that is operated by an electromagnet. The electromagnet is activated by a separate low-power signal from a micro controller. When activated, the electromagnet pulls to either open or close an electrical circuit.
    Relay Module

    Buy it here: 1 Channel 5V Relay Module 

  5. Bread board: A breadboard is a rectangular board with many mounting holes. They are used for creating electrical connections between electronic components and single board computers or microcontrollers such as Arduino and Raspberry Pi. The connections aren't permanent and they can be removed and placed again.
    Buy it here: Breadboard 830 Points 

  6. Jumpers Wires: A jump wire (also known as jumper wire, or jumper) is an electrical wire, or group of them in a cable, with a connector or pin at each end (or sometimes without them simply "tinned"), which is normally used to interconnect the components of a breadboard or other prototype or test circuit, internally or with other equipment or components, without soldering.
    Jumpers Wires
    Buy it here: 
    Jumper Wire (Male to Male) 
    Jumper Wire (Female to Female) 
    Jumper Wire (Male to Female) 

  7. BC547: The BC547 transistor is an NPN transistor. A transistor is nothing but the transfer of resistance which is used for amplifying the current.
    BC547, transistor, npn, pnp

    Buy it here: BC547 Transistor

  8. 9V Battery: This is used as the power source for this project.
    9V Battery

    Buy it here: 9V Battery 
The complete kit can be purchased at Soil Monitoring Kit

    Software used in this project:

    1. BLYNK: Blynk is a Platform with IOS and Android apps to control Arduino, Raspberry Pi and the likes over the Internet. It’s a digital dashboard where you can build a graphic interface for your project by simply dragging and dropping widgets.

      Get the Blink IoT Application for this Do It Yourself project.

    2. Arduino Software (IDE): The open-source Arduino Software (IDE) makes it easy to write code and upload it to the board. It runs on Windows, Mac OS X, and Linux.

      Get the Arduino Software (IDE) for this DIY project

    How does this system work:

    Sensor and data acquisition:

    This stage consists of the moisture sensor to measure the amount of water in the soil. The sensor converts moisture, content into electronic signals and send them to microcontroller.


    The microcontroller used in this study is Node MCU 8266. Its work is to process the data from sensors and control the status of the pump depending to the sensed data. Node MCU 8266 receives measures value from moisture sensor in form of analog voltages and digitizes them. The controller output is sent as a digital control to the water pump via the relay. The sensed data obtained are transmitted through wireless transmission and the user can monitor them through his or her mobile by using mobile application platform. In this project Blynk have been used as mobile application platform to read sensor data and control hardware remotely. If soil moisture is less than the threshold value, we get the notification on our phone so we can switch ON the water pump and if the soil moisture, exceed the threshold value which we can see on our Blynk app and therefore can turn OFF the water pump.

    Steps to implement this Soil Moisture Monitoring and Watering System

    IoT based plant monitoring system is capable of automating the process by analyzing the moisture of soil. Also, the data of sensors will be displayed on Blynk page. When the power supply is ON, the microcontroller checks the soil moisture content. If the moisture content is not up to the threshold then it sends the notification on our phone and we can switch ON the water pump and if it reaches the threshold level we can turn OFF the water pump. Advantages of these methods are that it is a cost-effective, increase efficiency and decrease wastage, easy to monitor, reduces man cost.

    Flowchart for the Moisture Check and Automated Plant Watering Solution:

    Make Plant Weather Monitoring System Step Guide

    Circuit Diagram:
    Node MCU Relay Soil Moisture Sensor Transistor Motor Pump Plant Weather Monitoring Circuit

    A0 Connected to analog pin of soil moisture sensor
    Vin  Connected to VCC of soil moisture sensor
    GND Connected to GND of soil moisture sensor and emitter of NPN transistor


    Arduino IDE Serial Code

    Making a plant weather monitoring system DIY experiment
    Blynk App Screenshot for Plant Weather Monitoring System

    Outcome of the product:

    Plant watering becomes easy, accurate and practical with the idea above shared. The output from moisture sensor plays major role in producing the output. Thus the “PLANT MONITORING AND AUTOMATED WATERING SYSTEM” has been designed and tested successfully. It has been developed by integrating all the hardware components mentioned. Presence of every module has been reasoned above and placed carefully in order to contribute to the best working of the unit.

    Diy projects

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