#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <DHT.h>
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define DHTPIN 2
#define DHTTYPE DHT22
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
DHT dht(DHTPIN, DHTTYPE);
String displayString;
void setup() {
  Serial.begin(9600);
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    while (true);
  }
  delay(2000);
  oled.clearDisplay();
  oled.setTextSize(2);
  oled.setTextColor(WHITE);
  oled.setCursor(0, 10);
  dht.begin();
  displayString.reserve(10);
}
void loop() {
  float humi = dht.readHumidity();
  float tempC = dht.readTemperature();
  if (isnan(humi) || isnan(tempC)) {
    displayString = "Failed";
  } else {
    displayString = String(tempC, 1);
    displayString += "°C";
    displayString += String(humi, 1);
    displayString += "%";
  }
  Serial.println(displayString);
  oledDisplayCenter(displayString);
}
void oledDisplayCenter(String text) {
  int16_t x1;
  int16_t y1;
  uint16_t width;
  uint16_t height;
  oled.getTextBounds(text, 0, 0, &x1, &y1, &width, &height);
  oled.clearDisplay();
  oled.setCursor((SCREEN_WIDTH - width) / 2, (SCREEN_HEIGHT - height) / 2);
  oled.println(text);
  oled.display();
}