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Plant Monitor

This project automatically waters plants by activating a water pump when the soil humidity falls below a specific threshold. Additionally, it displays temperature, humidity, and soil moisture on an LCD screen, providing users with insights into the plant’s growth environment.

Required Components

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name	ITEMS IN THIS KIT	LINK
Elite Explorer Kit	300+	Elite Explorer Kit

You can also buy them separately from the links below.

COMPONENT INTRODUCTION	PURCHASE LINK
Arduino Uno R4 WiFi	-
Breadboard	BUY
Jumper Wires	BUY
I2C LCD1602	BUY
DC Water Pump	-
TA6586 - Motor Driver Chip	-
Soil Moisture Module	BUY
Humiture Sensor Module	BUY
Power Supply Module	-

Wiring

Note

To protect the Power Supply Module’s Power Pack, please fully charge it before using it for the first time.

Schematic

Code

Note

• You can open the file 08_plant_monitor.ino under the path of elite-explorer-kit-main\fun_project\08_plant_monitor directly.

• Or copy this code into Arduino IDE.

Note

To install the library, use the Arduino Library Manager and search for “DHT sensor library” and “LiquidCrystal I2C” and install them.

08_plant_monitor.ino

/*
  Automatic watering system based on soil moisture, temperature, and humidity readings.

  Board: Arduino Uno R4 
  Component: I2C LCD1602, DC Water Pump with TA6586 Motor Driver Chip, Soil Moisture Module, and Humiture Sensor Module
  Library: https://www.arduino.cc/reference/en/libraries/liquidcrystal-i2c/ (LiquidCrystal I2C by Frank de Brabander)
           https://github.com/adafruit/DHT-sensor-library  (DHT sensor library by Adafruit)
*/


#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <DHT.h>

#define DHTPIN 4              // Digital pin for DHT11 sensor
#define DHTTYPE DHT11         // DHT11 sensor type
#define SOIL_MOISTURE_PIN A0  // Analog pin for soil moisture sensor
#define WATER_PUMP_PIN 8      // Digital pin for water pump


// Initialize sensor and LCD objects
DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  // Set pin modes
  pinMode(SOIL_MOISTURE_PIN, INPUT);
  pinMode(WATER_PUMP_PIN, OUTPUT);

  // Initialize water pump as off
  digitalWrite(WATER_PUMP_PIN, LOW);

  // Initialize LCD and backlight
  lcd.init();
  lcd.backlight();

  // Start DHT sensor
  dht.begin();
}

void loop() {
  // Read humidity and temperature from DHT11
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  // Read soil moisture level
  int soilMoisture = analogRead(SOIL_MOISTURE_PIN);

  // Display temperature and humidity on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Temp: " + String(temperature) + "C");
  lcd.setCursor(0, 1);
  lcd.print("Humidity: " + String(humidity) + "%");

  delay(2000);

  // Display soil moisture on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Soil Moisture: ");
  lcd.setCursor(0, 1);
  lcd.print(String(soilMoisture));

  // Activate water pump if soil is dry
  if (soilMoisture > 580) {
    digitalWrite(WATER_PUMP_PIN, HIGH);  // Turn on water pump
    delay(1000);                         // Pump water for 1 second
    digitalWrite(WATER_PUMP_PIN, LOW);   // Turn off water pump
  }

  delay(2000);  // Wait before next loop iteration
}

How it works?

Here is a detailed explanation of the code:

1. Library Inclusions and Constants/Variables:

   Import Wire.h, LiquidCrystal_I2C.h, and DHT.h libraries. Define pin numbers and other parameters related to DHT11, soil moisture sensor, and the water pump.

2. setup():

   Initialize the pin modes related to the soil moisture sensor and the water pump. Turn off the water pump initially. Initialize the LCD display and turn on the backlight. Start the DHT sensor.

3. loop():

   Read humidity and temperature from the DHT sensor. Read soil moisture from the soil moisture sensor. Display temperature and humidity values on the LCD screen, then clear the screen and display the soil moisture value. Determine whether to activate the water pump based on soil moisture. If the soil moisture is below 500 (a configurable threshold), activate the water pump for 1 second.