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

#define SCREEN_WIDTH 128   // OLED display width, in pixels
#define SCREEN_HEIGHT 64   // OLED display height, in pixels
#define ledbuzz 7

#define Sensor_smoke A0
#define OLED_RESET -1
#define SCREEN_ADDRESS 0x3C

#define MY_BLUE_COLOR SSD1306_WHITE // Change to SSD1306_BLACK for dark text on blue background

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

void setup() {
  Serial.begin(9600);

  pinMode(ledbuzz, OUTPUT);

  pinMode(Sensor_smoke, INPUT);

  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println(F("DLD Project: Natural Gas Detector"));
  display.display();
  delay(3000);
  display.clearDisplay();
  display.setCursor(0, 0);
  display.setTextSize(1);
  display.println(F("Made by Munawar Abbas "));
  display.println(F("and Muhammad Saeed "));
  display.display();
  delay(3000);
}

void loop() {
  
  digitalWrite(ledbuzz, LOW);

  display.clearDisplay();
  display.setTextSize(3);
  display.setCursor(0, 0);
  display.setTextColor(SSD1306_WHITE);
  drawHappyFace();
  display.display();

  display.clearDisplay();
  display.setTextSize(1);
  display.setCursor(0, 0);
  
  float temp = analogRead(Sensor_smoke);
  float temp2 = temp * (5.0 / 1023.0);
  
  // Serial output of gas sensor reading
  Serial.print("Gas Value: ");
  Serial.println(temp); // Serial print the raw sensor value

  if (temp > 150) {
    // Blink the LED and beep the buzzer rapidly
    while (temp > 150) { // Run loop until temp is above 70
     for (int i=0;i<10;i++){
      digitalWrite(ledbuzz, HIGH);
      delay(100);
      digitalWrite(ledbuzz, LOW);
      delay(50);
     }
      digitalWrite(ledbuzz, HIGH);
      display.clearDisplay();
      display.setTextColor(MY_BLUE_COLOR);
      display.println(F("Gas leak detected!"));
      display.setCursor(0, 10);
      display.print(F("Gas value: "));
      display.print(temp);
      display.display();
      
      // Wait for a short time before checking temperature again
      delay(100); 
      
      // Update temperature value
      temp = analogRead(Sensor_smoke);
      temp2 = temp * (5.0 / 1023.0);
    }
    
    // Clear the display and turn off the LED and buzzer once the temperature is below 70
    digitalWrite(ledbuzz, LOW);
    
    display.clearDisplay();
  } else {
    display.setTextColor(MY_BLUE_COLOR); // Using the defined blue color
    display.println(F("No gas leak detected"));
    drawHappyFace();
    display.display();
    
  }
}

void drawHappyFace() {
  
  display.setCursor(32, 10);
  display.print(F(":)"));
  display.setCursor(32, 30);
  display.print(F(" "));
  delay(1000);
 
}