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

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

#define OLED_RESET -1    // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C // Address of OLED display (for most SSD1306 modules)

#define DHT_PIN 22       // Pin connected to the DHT22 sensor

#define TRIGGER_PIN 23   // Pin connected to the ultrasonic sensor's trigger pin
#define ECHO_PIN 25      // Pin connected to the ultrasonic sensor's echo pin

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

DHT dht(DHT_PIN, DHT22); // Initialize DHT sensor

void setup() {
  Serial.begin(9600);
  
  // Initialize OLED display
  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  
  // Initialize DHT sensor
  dht.begin();

  // Clear the buffer
  display.clearDisplay();

  // Set text size and color
  display.setTextSize(1);
  display.setTextColor(WHITE);
}

void loop() {
  // Read temperature and humidity from DHT sensor
  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature();

  // Print temperature and humidity to serial monitor
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" *C");

  // Read distance from ultrasonic sensor
  long duration, distance;
  pinMode(TRIGGER_PIN, OUTPUT);
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);
  pinMode(ECHO_PIN, INPUT);
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.034 / 2; // Calculate distance in cm

  // Print distance to serial monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Clear previous display content
  display.clearDisplay();

  // Display data on OLED
  display.setCursor(0, 0);
  display.print("Humidity: ");
  display.print(humidity);
  display.println(" %");
  display.print("Temperature: ");
  display.print(temperature);
  display.println(" *C");
  display.print("Distance: ");
  display.print(distance);
  display.println(" cm");

  // Display the updated buffer
  display.display();

  // Delay before next reading
  delay(2000);
}