DIY IoT Plant Watering System Using Arduino

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DIY IoT Plant Watering System Using Arduino

Forgot to water your plants again? No worries! This smart plant watering system ensures your plants stay hydrated, even when you're away. With remote control via the Blynk app, you can monitor soil moisture levels and activate the water pump from anywhere. Plus, the onboard LED matrix brings your plants to life with fun expressions based on moisture levels like happy when watered, sad when thirsty!

This easy DIY project uses simple components to make plant care effortless and engaging. Whether you're a gardening enthusiast or just getting started, it's the perfect way to keep your plants healthy and happy!

Supplies

Arduino UNO R4 WiFi Development Board
Soil moisture sensor FC-28
12V Power Adapter
Connecting wires
5V Single Channel Relay Module
5V Water Pump
USB to Micro USB-C cable
Blynk Mobile App
Arduino IDE

Overview of Remote Plant Watering System

Maintaining the right balance of water for plants is crucial, but sometimes in the rush of daily life, it's easy to forget to water them. After coming back home and realizing that our plants have gone dull without water, I often wondered if there was a way to water them remotely, from anywhere. This idea led me to create a simple and effective plant watering system using Arduino. Through this project, we can monitor and water our plants by controlling a water pump remotely via Mobile App. Whether we're on vacation or just away from home, the system ensures that our plants stay hydrated, without worrying about watering them.

Let's Visualize the System Architecture With Block Diagram

The above block diagram gives us a clear view of how this IoT plant watering system will works.

Setting Up the Circuit for Remote Watering System

This circuit uses an Arduino UNO R4 WiFi as the main controller, but you can swap it with any microcontroller with minor code modifications. The built-in LED matrix on the UNO R4 is used to mimic plant facial expressions.

Here is a summary of the connections:

The soil moisture sensor connects to the Arduino’s analog input pin (A0), which reads the soil moisture level.
Since Arduino’s GPIO pins can't directly drive the pump, a relay module with an external power source is used instead of a motor driver. The water pump is controlled via the relay module, which switches the pump on or off depending on the moisture level in the soil.
The relay module and sensor are powered by the Arduino's 5V pin, while the water pump can be powered by either the Arduino or an external power source.

Preparing Hardware Setup With the Help of Circuit Diagram

Here’s how I assembled the system, I’ve set up the Arduino UNO R4 Wi-Fi using a USB-C connection for power supply. So, I don't need to provide an external power supply. I am able to provide a power supply to the water pump from the Arduino 5V pin itself.

Main reason I power Arduino through a USB port, so that it bypasses the voltage regulator present on the Arduino Uno R4 WiFi board, so we can consume current up to 2 mA from the 5V pin, which is enough for driving all these things including the Water Pump too.

Setting Up the Blynk for IoT Based Control

To control the watering system remotely, I used the Blynk app, which requires generating an Auth Token and Template ID. Here’s how you can set up the Blynk app:

Create a Blynk Account by Signing up or log in at Blynk.io.
After that enable developer mode In the developer section, create a new template for the plant watering system and configure it for remote control.
Once the template is created, link a new device to it and get the Auth Token for the Arduino to connect with the Blynk cloud.

We already covered a tutorial for generating the Blynk Auth Token for this project, You can check there.

Customize Blynk App Widget for Moisture Monitoring and Pump Control

Once the Blynk auth code is set up, you can move to the Blynk mobile app to configure the control interface. Here’s what to do:

Install the Blynk IoT app from your app store and log in with your credentials.
Create and customize a template for the watering system. Add necessary widgets, such as a button to control the pump and a radial gauge to display the soil moisture level.
Set the virtual pins in Blynk for the gauge and button. The radial gauge displays the moisture levels, while the button controls the water pump.

You can also check out this Blynk Widget Customization guide, For step-by-step instructions on customizing the Blynk app interface as shown in the above image.

Flash the Code in Arduino UNO R4

This is the code, which going to turn your normal Arduino board to an functional remote plant watering system, Let's dump this code.

/*************************************************************

Automatic plant watering system Arduino Code

More details : https://circuitdigest.com/microcontroller-projects/build-a-simple-plant…

************************************************************/

/* Comment this out to disable prints and save space */

//#define BLYNK_PRINT Serial

/* Fill in information from Blynk Device Info here */

#define BLYNK_TEMPLATE_ID "xxx"

#define BLYNK_TEMPLATE_NAME "IOT WATERING APP"

#define BLYNK_AUTH_TOKEN "xxxx-lDh"

#include <SPI.h>

#include <WiFiS3.h>

#include <BlynkSimpleWifi.h>

#include "Arduino_LED_Matrix.h"

#include <EEPROM.h>

#define moisture_sensor A0

#define relay 7

BlynkTimer timer;

ArduinoLEDMatrix matrix; //Create an led matrix object

// Your WiFi credentials.

// Set password to "" for open networks.

char ssid[] = "Semicon Media";

char pass[] = "xxxxx";

int eeprom_addr = 0; //eeprom address

int sensorValue = 0; // variable to store the value coming from the sensor

int prev_pump_status = 0;

int pump_status = 0;

float moist_percent = 0.00;

const uint32_t HAPPY_LED[] = {

0x3fc48a95,

0x58019fd9,

0x5889871

};

const uint32_t NORMAL_LED[] = {

0x3fc40298,

0xd98d8019,

0x5889871

};

const uint32_t SAD_LED[] = {

0x3fc48a9d,

0xd8898018,

0x71889905

};

BLYNK_WRITE(V1){ //read data from Blynk cloud

pump_status = param.asInt();

EEPROM.write(eeprom_addr,pump_status);

prev_pump_status = EEPROM.read(eeprom_addr);

Serial.println(prev_pump_status);

Serial.println(pump_status);

}

void sendSensor(){ //send data to Blynk cloud

Blynk.virtualWrite(V0,moist_percent);

}

void init_renesas_MCU_IO(){

pinMode(relay, OUTPUT);

pinMode(moisture_sensor, INPUT);

analogReadResolution(12); //change to 12-bit resolution

matrix.begin(); //initialise the led matrix*/

}

void track_soil_moisture(){

// read the value from the sensor:

sensorValue = analogRead(moisture_sensor);

moist_percent = 100 - ((float)sensorValue / 4096.0) * 100;

if(moist_percent >= 0 && moist_percent < 33.33){

Serial.println("DRY");

matrix.loadFrame(SAD_LED);

}

else if(moist_percent >= 33.33 && moist_percent < 66.66){

Serial.println("MODERATE");

matrix.loadFrame(NORMAL_LED);

}

else if(moist_percent >= 66.66 && moist_percent <= 100){

Serial.println("WET");

matrix.loadFrame(HAPPY_LED);

}

void setup()

{

// Debug console

Serial.begin(9600);

Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);

init_renesas_MCU_IO();

timer.setInterval(1000L,sendSensor);

prev_pump_status = EEPROM.read(eeprom_addr);

pump_status = prev_pump_status;

}

void loop()

{

Blynk.run();

timer.run();

track_soil_moisture();

if(pump_status == 0){

Serial.println("Water pump is off");

digitalWrite(relay, LOW);

}

else if(pump_status == 1){

Serial.println("Water pump is on");

digitalWrite(relay,HIGH);

}

delay(500);

}

Let's Watchout Plant Expression

After dumping the code, the Arduino UNO starts to display plant expression based on the soil moisture level.

Laughing Expression appears when the soil is very wet.
Smile Expression appears when the soil has a moderate moisture level.
Sad Expression appears when the soil is dry.

Bringing Life to Your Plants

The plant watering system offers a smart and interactive approach by integrating an LED matrix to display diverse facial expressions based on soil moisture levels, making plant care both efficient and engaging.

No matter if you're a seasoned gardener or just starting out, this system makes plant care both exciting and effortless. Ready to create your own smart watering setup? Check out our official guide on Smart Plant Watering system with LED Expressions to get started!