#define AO_PIN 34  // ESP32's pin GPIO36 connected to AO pin of the MQ2 sensor

void setup() {
  // initialize serial communication
  Serial.begin(9600);

  // set the ADC attenuation to 11 dB (up to ~3.3V input)
  //analogSetAttenuation(ADC_11db);
  //Serial.println("Warming up the MQ2 sensor");
  //delay(20000);  // wait for the MQ2 to warm up
}

void loop() {
  int gasValue = analogRead(AO_PIN);

  Serial.print("MQ2 sensor AO value: ");
  Serial.println(gasValue);
}