#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 ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32

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

#define DHTPIN 2       // Pin where the DHT22 is connected
#define DHTTYPE DHT22  // DHT 22  

DHT dht(DHTPIN, DHTTYPE);

void setup() {
  // initialize with the I2C addr 0x3C (for the 128x64)
  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }
  
  display.display(); // Clear the buffer
  display.setTextColor(SSD1306_WHITE); // Draw white text
  display.setTextSize(1);              // Draw 1X-scale text
  display.setCursor(0,0);             // Start at top-left corner
  display.display();
  delay(2000);

  dht.begin();
}

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

  // Check if any reads failed and exit early (to try again).
  if (isnan(humidity) || isnan(temperature)) {
    display.clearDisplay();
    display.setCursor(0, 0);
    display.println("Failed to read");
    display.println("from DHT sensor!");
    display.display();
    delay(2000);
    return;
  }

  // Print the data on the OLED display
  display.clearDisplay();
  display.setCursor(0, 0);
  display.print("Temp: ");
  display.print(temperature);
  display.print(" C");
  display.setCursor(0, 16);
  display.print("Humidity: ");
  display.print(humidity);
  display.print(" %");
  display.display();

  delay(2000);  // Delay between readings
}