#define MQ2_Ae A1
#define MQ2_De 2

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(MQ2_Ae, INPUT);
  pinMode(MQ2_De, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.print("Analog: ");
  Serial.println(analogRead(MQ2_Ae));
  Serial.print("Digital: ");
  Serial.println(digitalRead(MQ2_De));
  delay(1000);
}