// Air Quality MQ135 sensor 
// by BARRAGAN <http://barraganstudio.com>

// Reads values from an air quality sensor connected to the 
// analog input pin 0. The value read from the sensor is proportional
// to the air quality measured by the sensor.
// The value read is printed through the serial to be monitored
// in the console.

// Created 5 April 2009

int val; 

void setup()
{
  Serial.begin(9600);           // sets the serial port to 9600
}

void loop() 
{
  val = analogRead(0);          // read analog input pin 0
  Serial.print(val, DEC);       // prints the value read
  Serial.print(" ");		// prints a space between the numbers
  delay(100);                   // wait 100ms for next reading
}
