const int ledPin1 =  11;      // the number of the LED pin 
const int ledPin2 =  10;      // the number of the LED pin 
int sensorPin = A0; 
int sensorValue = 0;           // variables will change: 
 
void setup() 
{                                                // initialize the LED pin as an output:   
  pinMode(ledPin1, OUTPUT);    
  pinMode(ledPin2, OUTPUT);    
  Serial.begin(9600);                                 //sets the data rate for serial data transmission:     
   
} 
 
void loop()  
{                                                                // read the state of the sensor value: 
  sensorValue = analogRead(sensorPin); 
 
  if (sensorValue > 400) 
  { 
                                               // turn LED1 on:   
digitalWrite(ledPin1, HIGH);    
digitalWrite(ledPin2, LOW); 
delay(100);                             //delay period equal to 0.1 second 
 
  }  
  else 
  {                                            // turn LED1 off: 
    digitalWrite(ledPin1, LOW);    
    digitalWrite(ledPin2, HIGH); 
    delay(100); 
  } 
 
  Serial.print("\n sensor = "); 
  Serial.print(sensorValue); 
}