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

#define DHTPIN 2 // Pin connected to the DHT22 sensor
#define OLED_RESET 4 // Reset pin for the OLED display
#define Buzzer 3

Adafruit_SSD1306 display(OLED_RESET);

void setup() {
  tone(Buzzer, 1000);
  // Initialize the OLED display
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.display();
  delay(2000);
  display.clearDisplay();
  noTone(Buzzer);

}

void loop() {
  // Read temperature and humidity values from the DHT22 sensor
  float temperature = readTemperature();
  float humidity = readHumidity();

  // Display temperature and humidity on the OLED display
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.print("Temperature: ");
  display.print(temperature);
  display.println(" C");
  display.print("Humidity: ");
  display.print(humidity);
  display.println(" %");
  display.display();


  delay(200); // Delay between readings
}

float readTemperature() {
  // Request temperature data from the DHT22 sensor
  pinMode(DHTPIN, OUTPUT);
  digitalWrite(DHTPIN, LOW);
  delay(20);
  digitalWrite(DHTPIN, HIGH);
  delayMicroseconds(40);
  pinMode(DHTPIN, INPUT);

  // Wait for the DHT22 sensor to respond
  while (digitalRead(DHTPIN) == LOW)
    ;
  while (digitalRead(DHTPIN) == HIGH)
    ;

  // Read the temperature value from the DHT22 sensor
  int data[5];
  for (int i = 0; i < 5; i++) {
    data[i] = readByte();
  }

  // Calculate the temperature
  float temperature = ((data[2] & 0x7F) << 8 | data[3]) / 10.0;
  if (data[2] >> 7)
    temperature = -temperature;

  return temperature;
}

float readHumidity() {
  // Request humidity data from the DHT22 sensor
  pinMode(DHTPIN, OUTPUT);
  digitalWrite(DHTPIN, LOW);
  delay(20);
  digitalWrite(DHTPIN, HIGH);
  delayMicroseconds(40);
  pinMode(DHTPIN, INPUT);

  // Wait for the DHT22 sensor to respond
  while (digitalRead(DHTPIN) == LOW)
    ;
  while (digitalRead(DHTPIN) == HIGH)
    ;

  // Read the humidity value from the DHT22 sensor
  int data[5];
  for (int i = 0; i < 5; i++) {
    data[i] = readByte();
  }

  // Calculate the humidity
  float humidity = (data[0] << 8 | data[1]) / 10.0;

  return humidity;
}

int readByte() {
  int value = 0;
  for (int i = 0; i < 8; i++) {
    while (digitalRead(DHTPIN) == LOW)
      ;
    delayMicroseconds(30);
    if (digitalRead(DHTPIN) == HIGH)
      value |= (1 << (7 - i));
    while (digitalRead(DHTPIN) == HIGH)
      ;
  }
  return value;
}