Smart Thermostat System

#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <DHT.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
#define DHTPIN         4
#define DHTTYPE        DHT11
#define RELAYPIN       3
#define TEMP_THRESHOLD_HIGH 24
#define TEMP_THRESHOLD_LOW  20

DHT dht(DHTPIN, DHTTYPE);
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void setup() {
  pinMode(RELAYPIN, OUTPUT);
  dht.begin();

  // Initialize OLED display
  if(!display.begin(SSD1306_I2C_ADDRESS, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.println(F("Smart Thermostat"));
  display.display();
  delay(2000);  // Pause for 2 seconds
}

void loop() {
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  if (isnan(humidity) || isnan(temperature)) {
    display.clearDisplay();
    display.setCursor(0,0);
    display.println(F("Failed to read from DHT sensor!"));
    display.display();
    delay(2000); // Pause for 2 seconds
    return;
  }

  // Control relay based on temperature thresholds
  if (temperature > TEMP_THRESHOLD_HIGH) {
    digitalWrite(RELAYPIN, HIGH);  // Turn on cooling
  } else if (temperature < TEMP_THRESHOLD_LOW) {
    digitalWrite(RELAYPIN, LOW);   // Turn off cooling
  }

  // Display temperature and humidity on OLED
  display.clearDisplay();
  display.setCursor(0,0);
  display.print(F("Temp: "));
  display.print(temperature);
  display.println(F(" C"));
  display.print(F("Humidity: "));
  display.print(humidity);
  display.println(F(" %"));
  display.display();
  
  delay(2000); // Wait for 2 seconds before the next read
}