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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

const int mq135Pin = 34;
const int ledPin = 25;

float voltage = 0;
int sensorValue = 0;
float airQuality = 0;

void setup() {
  Serial.begin(115200);

  pinMode(ledPin, OUTPUT);

  Wire.begin(21, 22);

  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println("OLED no encontrada");
    while(true);
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
}

void loop() {
  sensorValue = analogRead(mq135Pin);
  voltage = sensorValue * (3.3 / 4095.0);

  airQuality = map(sensorValue, 0, 4095, 0, 500);

  // 🚨 Control del LED
  if (airQuality > 150) {
    digitalWrite(ledPin, HIGH); // Enciende alerta
  } else {
    digitalWrite(ledPin, LOW);  // Apaga alerta
  }

  Serial.print("Sensor: ");
  Serial.print(sensorValue);
  Serial.print(" AQI: ");
  Serial.println(airQuality);

  display.clearDisplay();
  display.setCursor(0, 10);
  display.println("Calidad Aire");

  display.setCursor(0, 30);
  display.print("Valor: ");
  display.println(sensorValue);

  display.setCursor(0, 45);
  display.print("AQI: ");
  display.println(airQuality);

  display.display();

  delay(2000);
}