Building up plant irrigation system for your domestic use is quite easy and simple. It would take only 15 minutes to build one , if you have all the right ingredients in place. Let’s take a look at building one
Wiring Diagram
Author: santronix

Published August 11, 2019 © Apache-2.0

IoT- Plant Irrigation System

Build your own automatic IoT plant irrigation system with soil sensor, Particle Photon, relay and immersible water motor.

BeginnerFull instructions provided30 minutes6,894

Things used in this project

Hardware components

Particle Photon

5V relay

Soil Moisture Sensor

Immersive water motor

Software apps and online services

Particle Build Web IDE

Hand tools and fabrication machines

Soldering iron (generic)

10 Pc. Jumper Wire Kit, 5 cm Long

Story

Building up plant irrigation system for your domestic use is quite easy and simple. It would take only 15 minutes to build one , if you have all the right ingredients in place. Let’s take a look at building one…

How does it work?

It’s simple, the system works on the principle of Sensing and Actuation on a local micro-controller. A soil moisture sensor would detect the moisture level of the soil and provide the analog output, this value then would be used by micro-controller program to compare against the threshold value. If the soil moisture goes below the predefined value then the sequence of relay actuation followed by start of immersion water motor will occur which will automatically water the plants, until again the soil moisture level is detected to be higher than the threshold value, at which time the relay will open, stopping the water.

Advantages

Water the plants regularly, making sure plants get water as and when needed
Water conservation by Intelligence
Automatic watering ensures peace of mind (Comfort)

Ingredients

There are quite few components required to build this system. You can ideally use any micro-controller (but then you have to make sure of the software accordingly). We used Particle Photon board to build one, although the program written would work perfect with any Arduino compatible board. So what we need?

Hardware

Particle Photon x1 Click to buy

Soil Moisture sensor x1 Click to buy

5V Relay x1 Click to buy

Immersion motor x1 Click to buy

Tools

Soldering Iron Click to buy

Jumper cables Click to buy

Software

Particle Photon Web IDE or IDE Software Go here

Program Code DOWNLOAD HERE

Wiring Diagram

Here’s how you should interface all the hardware

Connections details

Soil moisture sensor Vcc to VIN (3V3) of Particle Photon
Soil moisture sensor GND to Particle Photon GND
Soil moisture sensor Analog out to Particle Photon A0
Particle Photon VIN to Relay Power
Particle Photon D7 to Relay Input signal
Particle Photon GND to Relay GND
Relay NO connection to immersive motor

Once the hardware is wired appropriately then its time to flash the program. You can use Particle Web IDE or download IDE to your mac or Windows computer and flash the program.

Once everything is set, just power on the system using 5V to Particle Photon. Your relay, moisture sensor and immersive motor will get energized if the connections are all good. As we have given a polling time of 5s, wait for some time. Please ensure that the soil moisture sensor is dipped in the soil. You can see the below video to ensure everything is setup correctly.

Author: santronix

Code

Source code for Plant irrigation system

#define WetSoilValue        3200
#define SensorPin           A0
#define MotorPin            7
#define PublishInterval     5000

int WetSoilValueReached = false;
unsigned long LastTextTime = 0;

void setup() {
    pinMode(SensorPin, INPUT);
    pinMode(MotorPin, OUTPUT);
}

void loop() {
    if(analogRead(SensorPin) < WetSoilValue){
        WetSoilValueReached = true;
        digitalWrite(MotorPin, LOW);
        
        unsigned long now = millis();
        
        if (now - LastTextTime >= PublishInterval) { 
            Particle.publish("Soil moisture low, turning on sprinklers!");
        }
    }else{
        WetSoilValueReached = false;
        digitalWrite(MotorPin, HIGH);
    }
    delay(5000);
}

Credits

Santosh Ambekar

11 projects • 19 followers

Santosh is an IoT enthusiastic and expert in the field of automation and software development.

IoT- Plant Irrigation System