int gas = 32;
int led = 17;
int threshold=400;
void setup(){
  pinMode(gas,INPUT);
  pinMode(led,OUTPUT);
  Serial.begin(9600);
}
void loop(){
  int g = analogRead(gas);
  Serial.println(g);
  if(g>threshold){
    Serial.println("Harmful gas detected");
    digitalWrite(led,1);

 }
 else{
    Serial.println("No gas detected");
    digitalWrite(led,0);
 }
}