#define MQ2_ANA A0

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(MQ2_ANA, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.print("Analog: ");
  Serial.println(analogRead(MQ2_ANA));

  delay(1000);
}