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

// Define the number of sensors
#define NUM_SENSORS 5

// Define the pins where the sensors are connected
const int sensorPins[NUM_SENSORS] = {2, 3, 4, 5, 6};

// Initialize DHT sensors array for DHT22
DHT dhtSensors[NUM_SENSORS] = {
  DHT(sensorPins[0], DHT22),
  DHT(sensorPins[1], DHT22),
  DHT(sensorPins[2], DHT22),
  DHT(sensorPins[3], DHT22),
  DHT(sensorPins[4], DHT22)
};

// Initialize the LCD, address 0x27 for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x27, 16, 2);

unsigned long previousMillis = 0;
const long interval = 2000; // interval at which to read sensors and switch pages
int currentPage = 0;

void setup() {
  // Initialize Serial
  Serial.begin(9600);

  // Initialize the LCD with the correct parameters
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.print("Initializing...");

  // Initialize all DHT sensors
  for (int i = 0; i < NUM_SENSORS; i++) {
    dhtSensors[i].begin();
  }

  delay(2000); // Allow sensors some time to stabilize
  lcd.clear();
}

void loop() {
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;

    // Clear the LCD
    lcd.clear();

    // Display data for the current page
    displayData(currentPage);

    // Move to the next page
    currentPage = (currentPage + 1) % ((NUM_SENSORS + 1) / 2); // Adjusted for displaying two sensors per page
  }
}

void displayData(int page) {
  int sensorIndex1 = page * 2;
  int sensorIndex2 = sensorIndex1 + 1;

  // Buffers for formatted temperature strings
  char tempStr1[6]; // "XX.X"
  char tempStr2[6]; // "XX.X"

  // Read and display data from the first sensor on the current page
  if (sensorIndex1 < NUM_SENSORS) {
    float temp1 = dhtSensors[sensorIndex1].readTemperature();
    float hum1 = dhtSensors[sensorIndex1].readHumidity();

    if (isnan(temp1) || isnan(hum1)) {
      lcd.setCursor(0, 0);
      lcd.print("T");
      lcd.print(sensorIndex1 + 1);
      lcd.print(": Error");
      Serial.print("Sensor ");
      Serial.print(sensorIndex1 + 1);
      Serial.println(" - Error reading data");
    } else {
      dtostrf(temp1, 4, 1, tempStr1); // Format temperature to 1 decimal place
      lcd.setCursor(0, 0);
      lcd.print("T");
      lcd.print(sensorIndex1 + 1);
      lcd.print(":");
      lcd.print(tempStr1);
      lcd.print((char)223); // Degree symbol
      lcd.print("C H");
      lcd.print(sensorIndex1 + 1);
      lcd.print(":");
      lcd.print(hum1);
      lcd.print("%");

      // Print to Serial
      Serial.print("Sensor ");
      Serial.print(sensorIndex1 + 1);
      Serial.print(" - Humidity: ");
      Serial.print(hum1);
      Serial.print("%, Temp: ");
      Serial.print(temp1);
      Serial.println("°C");
    }
  }

  // Read and display data from the second sensor on the current page
  if (sensorIndex2 < NUM_SENSORS) {
    float temp2 = dhtSensors[sensorIndex2].readTemperature();
    float hum2 = dhtSensors[sensorIndex2].readHumidity();

  // Handle NaN readings
    if (isnan(temp2) || isnan(hum2)) {
      lcd.setCursor(0, 1);
      lcd.print("T");
      lcd.print(sensorIndex2 + 1);
      lcd.print(": Error");
      Serial.print("Sensor ");
      Serial.print(sensorIndex2 + 1);
      Serial.println(" - Error reading data");
    } else {
      dtostrf(temp2, 4, 1, tempStr2); // Format temperature to 1 decimal place
      lcd.setCursor(0, 1);
      lcd.print("T");
      lcd.print(sensorIndex2 + 1);
      lcd.print(":");
      lcd.print(tempStr2);
      lcd.print((char)223); // Degree symbol
      lcd.print("C H");
      lcd.print(sensorIndex2 + 1);
      lcd.print(":");
      lcd.print(hum2);
      lcd.print("%");

      // Print to Serial
      Serial.print("Sensor ");
      Serial.print(sensorIndex2 + 1);
      Serial.print(" - Humidity: ");
      Serial.print(hum2);
      Serial.print("%, Temp: ");
      Serial.print(temp2);
      Serial.println("°C");
    }
  }
}