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

// Define pins for DHT22 sensor and Soil Sensor
#define DHT22_PIN 13 // GPIO13 connected to DHT22 sensor
#define SOIL_SENSOR_PIN 34 // GPIO34 connected to Soil Moisture sensor (analog)

// Initialize the LCD (I2C address 0x27 and 16 columns, 2 rows)
LiquidCrystal_I2C lcd(0x27, 16, 2);  
DHT dht22(DHT22_PIN, DHT22);

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(115200);
  Serial.println("DHT22 and LCD initialization...");

  // Initialize I2C on GPIO 16 (SDA) and GPIO 17 (SCL)
  Wire.begin(16, 17);  
  dht22.begin();      // Initialize the DHT sensor
  lcd.init();         // Initialize the LCD I2C display
  lcd.backlight();    // Turn on the LCD backlight
}

void loop() {
  // Read humidity and temperature from DHT22 sensor
  float humidity = dht22.readHumidity();
  float temperature_C = dht22.readTemperature(); // Temperature in Celsius

  // Read soil moisture sensor value
  int soilMoistureValue = analogRead(SOIL_SENSOR_PIN); 
  String soilStatus = soilMoistureValue < 2165 ? "WET" : soilMoistureValue > 3135 ? "DRY" : "OK"; 

  // Debugging output for temperature, humidity, and soil status
  Serial.print("Temperature: ");
  Serial.print(temperature_C);
  Serial.println(" °C");
  
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.println(" %");
  
  Serial.print("Soil Moisture: ");
  Serial.print(soilMoistureValue);
  Serial.print(" (");
  Serial.print(soilStatus);
  Serial.println(")");

  lcd.clear();
  
  // Check whether the DHT22 readings are successful
  if (isnan(temperature_C) || isnan(humidity)) {
    lcd.setCursor(0, 0);
    lcd.print("Sensor Error");
    Serial.println("Failed to read from DHT22 sensor.");
  } else {
    // Display temperature and humidity on LCD (fit on Line 1)
    lcd.setCursor(0, 0);
    lcd.print("Tmp:");
    lcd.print(temperature_C, 1);  // Print temperature with 1 decimal place
    lcd.print("C Hu:");
    lcd.print(humidity, 0);  // Print humidity as an integer
    lcd.print("%");

    // Display soil status on LCD (Line 2)
    lcd.setCursor(0, 1);
    lcd.print("Soil: ");
    lcd.print(soilStatus);
  }

  // Wait 2 seconds between readings
  delay(2000);
}