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

// LCD setup
#define I2C_ADDR 0x27
#define LCD_COLUMNS 20
#define LCD_LINES 4
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

// DHT22 setup
#define DHTPIN1 2 // Pin for the first DHT22 sensor
#define DHTPIN2 3 // Pin for the second DHT22 sensor
#define DHTTYPE DHT22
DHT dht1(DHTPIN1, DHTTYPE);
DHT dht2(DHTPIN2, DHTTYPE);

// Timing variables
unsigned long lastUpdateTime = 0; // Store the last update time
const unsigned long updateInterval = 500; // Update every 500 ms (0.5 seconds)

void setup() {
  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Initializing...");

  // Initialize DHT sensors
  dht1.begin();
  dht2.begin();

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

void loop() {
  // Check if it's time to update the display
  if (millis() - lastUpdateTime >= updateInterval) {
    lastUpdateTime = millis(); // Reset the timer

    // Read data from DHT1
    float temp1 = dht1.readTemperature(true); // Fahrenheit
    float hum1 = dht1.readHumidity();

    // Read data from DHT2
    float temp2 = dht2.readTemperature(true); // Fahrenheit
    float hum2 = dht2.readHumidity();

    // Check for read errors
    if (isnan(temp1) || isnan(hum1) || isnan(temp2) || isnan(hum2)) {
      lcd.setCursor(0, 0);
      lcd.print("Sensor error!      ");
      return;
    }

    // Update LCD without flickering
    lcd.setCursor(0, 0);
    lcd.print("S1: ");
    lcd.print(temp1, 1);
    lcd.print("F ");
    lcd.print(hum1, 1);
    lcd.print("%   "); // Ensure to overwrite any leftover characters

    lcd.setCursor(0, 1);
    lcd.print("S2: ");
    lcd.print(temp2, 1);
    lcd.print("F ");
    lcd.print(hum2, 1);
    lcd.print("%   "); // Overwrite leftover characters

    lcd.setCursor(0, 2);
    lcd.print("Avg Temp: ");
    float avgTemp = (temp1 + temp2) / 2;
    lcd.print(avgTemp, 1);
    lcd.print("F   ");

    lcd.setCursor(0, 3);
    lcd.print("Avg Hum: ");
    float avgHum = (hum1 + hum2) / 2;
    lcd.print(avgHum, 1);
    lcd.print("%   ");
  }

  // You can add other non-blocking code here
}