#define MQ135 19
int thresholdvalue=400;
int gasvalue=0;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(32, OUTPUT);
  pinMode(26,OUTPUT);
  pinMode(0,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  gasvalue=analogRead(19);
  if(gasvalue<thresholdvalue){
    digitalWrite(32,HIGH);
    digitalWrite(26,LOW);
    Serial.print("AIR QUALITY IS GOOD");
    delay(4000);
  }
  else{
    digitalWrite(26,HIGH);
    digitalWrite(32,LOW);
    Serial.print("AIR QUALITY IS BAD");
    digitalWrite(0,HIGH);
    delay(4000);
  }
}