Greenhouse automation can significantly enhance the efficiency and productivity of your gardening efforts by controlling environmental factors such as temperature, humidity, lighting, and irrigation. Arduino, with its flexibility and affordability, is an excellent platform for creating a custom greenhouse automation system. In this article, we'll explore how to set up a basic automated greenhouse system using Arduino.

Examples:

Components Needed:

1. Arduino Uno: The brain of your automation system.
2. DHT22 Sensor: To monitor temperature and humidity.
3. Light Sensor (LDR): To measure light intensity.
4. Relay Module: To control high-power devices like fans or pumps.
5. Water Pump: For automated irrigation.
6. LED Grow Lights: To supplement natural sunlight.
7. Jumper Wires and Breadboard: For connections.
8. Power Supply: To power the Arduino and other components.

Setting Up the Arduino:

1. Connect the DHT22 Sensor:

   • Connect the VCC pin of the DHT22 to the 5V pin on the Arduino.
   • Connect the GND pin to the GND on the Arduino.
   • Connect the data pin to digital pin 2 on the Arduino.

2. Connect the Light Sensor (LDR):

   • Connect one end of the LDR to 5V and the other end to A0 on the Arduino.
   • Connect a 10k ohm resistor from A0 to GND.

3. Connect the Relay Module:

   • Connect the VCC pin of the relay module to 5V on the Arduino.
   • Connect the GND pin to GND on the Arduino.
   • Connect the IN1 pin to digital pin 3 on the Arduino.

4. Connect the Water Pump and LED Lights:

   • Connect the water pump and LED lights to the relay module as per the relay's specification.

Arduino Code:

#include <DHT.h>

#define DHTPIN 2     // Pin where the DHT22 is connected
#define DHTTYPE DHT22
#define LIGHT_SENSOR A0
#define RELAY_PIN 3

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  dht.begin();
  pinMode(RELAY_PIN, OUTPUT);
}

void loop() {
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();
  int lightIntensity = analogRead(LIGHT_SENSOR);

  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.print(" *C\t");
  Serial.print("Light Intensity: ");
  Serial.println(lightIntensity);

  // Example conditions to turn on the relay
  if (temperature > 30 || humidity < 40 || lightIntensity < 300) {
    digitalWrite(RELAY_PIN, HIGH);  // Turn on the relay
  } else {
    digitalWrite(RELAY_PIN, LOW);   // Turn off the relay
  }

  delay(2000);  // Wait for 2 seconds before the next reading
}

Explanation:

• DHT22 Sensor: This sensor measures both temperature and humidity. The readings are used to decide whether to activate the relay controlling the fan or water pump.
• Light Sensor (LDR): Measures the light intensity. If the light is below a certain threshold, the relay can be used to turn on LED grow lights.
• Relay Module: Acts as a switch to control high-power devices like water pumps and LED lights based on the sensor readings.

This setup can be expanded with additional sensors and actuators to further automate and optimize your greenhouse environment.