#include "DHT.h"
#include <SPI.h>
#include <SD.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define DHTPIN 2
#define DHTTYPE DHT22

#define CS_PIN 10

DHT dht(DHTPIN, DHTTYPE);
File dataFile;

#define OLED_RESET    -1
Adafruit_SSD1306 display(OLED_RESET);

void setup() {
  Serial.begin(9600);
  dht.begin();
  
  pinMode(CS_PIN, OUTPUT);

  if (!SD.begin(CS_PIN)) {
    Serial.println("SD initialization failed!");
    return;
  }
  Serial.println("SD initialization done.");
  
  dataFile = SD.open("data.txt", FILE_WRITE);
  if (!dataFile) {
    Serial.println("Error opening data file.");
    return;
  }
  Serial.println("Data file opened.");
  
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    for(;;);
  }

  display.display();
  delay(2000);  // Pause for 2 seconds
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
}

void loop() {
  delay(2000);  // Wait for 2 seconds between measurements

  float humidity = dht.readHumidity();
  float temperature = dht.readTemperature(); // Celsius

  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print("%\t");
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println("°C");

  dataFile.print("Humidity: ");
  dataFile.print(humidity);
  dataFile.print("%\t");
  dataFile.print("Temperature: ");
  dataFile.print(temperature);
  dataFile.println("°C");
  dataFile.flush(); // Ensure data is written to the card
  
  display.clearDisplay();
  display.setCursor(0,0);
  display.print(F("Humidity: "));
  display.print(humidity);
  display.println(F("%"));

  display.setCursor(0,10);
  display.print(F("Temperature: "));
  display.print(temperature);
  display.println(F("C"));

  display.display();
}