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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1  // Not used with I2C

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

int tempPin = 27;
const float BETA = 3950;
int ledPin = 32;
int buzzerPin = 25;



void setup() {
  Serial.begin(115200);
  pinMode(tempPin, INPUT);
  pinMode(ledPin, OUTPUT);

  // OLED Initialization
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for (;;); // Don't proceed, loop forever
  }

  display.clearDisplay();
  display.setTextSize(2);      // Large text
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Starting...");
  display.display();
  delay(1000);
}

void loop() {
  int analogValue = analogRead(tempPin);
  float celsius = 1 / (log(1 / (4095. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15;

  Serial.print("Temperature: ");
  Serial.print(celsius);
  Serial.println(" ℃");

  // OLED Display
  display.clearDisplay();
  display.setTextSize(2);
  display.setCursor(0, 0);
  display.print("Temp:");
  display.setCursor(0, 30);
  display.print(celsius, 1);  // One decimal place
  display.print(" C");
  display.display();

  if (celsius > 50) {
    Serial.println("Temperature limit reached, unsafe environment ");
    digitalWrite(ledPin, HIGH);
    tone(buzzerPin, 262, 500); 
  } else {
    Serial.println("Temperature levels are safe");
    digitalWrite(ledPin, LOW);
  }

  delay(1000);
}