🌡️ Temperature & Humidity Monitor Project

🔧 Components Needed

• Arduino Board (e.g., Arduino Uno or Arduino R4)
• DHT11 Sensor
• I2C LCD 1602 Display
• Jumper Wires
• Breadboard (optional for easy wiring)

📌 Wiring Connections

1. DHT11 Sensor:

• VCC (Red Wire): Connect to 5V on Arduino
• GND (Black Wire): Connect to GND on Arduino
• Data (Yellow Wire): Connect to a digital pin (we’ll use pin 2 in the code)

2. I2C LCD 1602 Display:

• VCC: Connect to 5V on Arduino
• GND: Connect to GND on Arduino
• SDA: Connect to Arduino A4 (on Uno) or appropriate I2C SDA pin on your board
• SCL: Connect to Arduino A5 (on Uno) or appropriate I2C SCL pin on your board

Note: The I2C address for the LCD is often 0x27. If yours is different, adjust the code accordingly.

💻 Code Example

Make sure to install the following libraries in your Arduino IDE:

• DHT sensor library (e.g., “DHT sensor library” by Adafruit)
• LiquidCrystal_I2C library

Here’s the code:

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

// ----- DHT Sensor Settings -----
#define DHTPIN 2           // DHT11 data pin connected to digital pin 2
#define DHTTYPE DHT11      // We're using the DHT11 sensor
DHT dht(DHTPIN, DHTTYPE);

// ----- LCD Settings -----
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Set the LCD I2C address to 0x27 with 16 columns and 2 rows

void setup() {
  Serial.begin(9600);
  dht.begin();            // Initialize DHT sensor
  
  // Initialize the LCD
  lcd.init();             
  lcd.backlight();        // Turn on the backlight
  lcd.setCursor(0, 0);
  lcd.print("Temp & Humidity");
  delay(2000);
}

void loop() {
  // ----- Wait a bit between measurements -----
  delay(2000);

  // ----- Read the humidity and temperature values -----
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  // Check if any reads failed and exit early (to try again)
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT sensor!");
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Sensor Error");
    return;
  }
  
  // ----- Print values to Serial Monitor for debugging -----
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print(" %  ");
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" *C");
  
  // ----- Display the temperature and humidity on the LCD -----
  lcd.clear();
  
  // Display temperature on the first row
  lcd.setCursor(0, 0);
  lcd.print("Temp: ");
  lcd.print(temperature);
  lcd.print((char)223);  // Degree symbol
  lcd.print("C");
  
  // Display humidity on the second row
  lcd.setCursor(0, 1);
  lcd.print("Hum:  ");
  lcd.print(humidity);
  lcd.print(" %");
}

📋 How It Works

• DHT Sensor:
  • The DHT11 sensor reads temperature and humidity values.
  • The dht.readHumidity() and dht.readTemperature() functions retrieve these values, and error-checking ensures valid data.
• I2C LCD Display:
  • The LiquidCrystal_I2C library initializes the LCD with a specified I2C address (commonly 0x27).
  • The code clears the display and updates it every 2 seconds with the current temperature (first row) and humidity (second row).
• Serial Monitor:
  • The data is also printed to the Serial Monitor for debugging and real-time tracking.

🎯 Project Enhancements

• Data Logging:
  • Save readings to an SD card for historical tracking.
• Wireless Connectivity:
  • Integrate a WiFi module (like the Arduino R4 WiFi) to send data to a cloud service.
• Alarm System:
  • Trigger alerts if temperature or humidity exceeds certain thresholds.

Enjoy building your Temperature & Humidity Monitor project with the DHT11 sensor and I2C LCD 1602! Happy coding! 😊👍