#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_Sensor.h>
#include "DHT.h"
#include <SPI.h>
#include <SD.h>
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET 4
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT);
#define DHTPIN 2
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);
// SD card CS pin
#define SD_CS 10
File dataFile;
void setup() {
Serial.begin(115200);
dht.begin();
// OLED init
display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
display.clearDisplay();
display.setTextColor(SSD1306_WHITE);
// SD card init
Serial.println("Initializing SD card...");
if (!SD.begin(SD_CS)) {
Serial.println("SD card failed or not present!");
} else {
Serial.println("SD card ready.");
// Create file header (optional)
dataFile = SD.open("datalog.txt", FILE_WRITE);
if (dataFile) {
dataFile.println("Temperature,Humidity");
dataFile.close();
}
}
}
void loop() {
delay(2000);
float t = dht.readTemperature();
float h = dht.readHumidity();
if (isnan(h) || isnan(t)) {
Serial.println("Failed to read from DHT sensor!");
return;
}
Serial.print("Temp: ");
Serial.print(t);
Serial.print(" C Humidity: ");
Serial.println(h);
// ================= OLED DISPLAY =================
display.clearDisplay();
display.setTextSize(1);
display.setCursor(0,7);
display.print("Temperature:");
display.setTextSize(2);
display.setCursor(0,16);
display.print(t);
display.print(" C");
display.setTextSize(1);
display.setCursor(0,37);
display.print("Humidity:");
display.setTextSize(2);
display.setCursor(0,50);
display.print(h);
display.print(" %");
display.display();
// ================= SD CARD SAVE =================
dataFile = SD.open("datalog.txt", FILE_WRITE);
if (dataFile) {
dataFile.print(t);
dataFile.print(",");
dataFile.println(h);
dataFile.close();
Serial.println("Data saved to SD card.");
} else {
Serial.println("Error opening file!");
}
}