int RED_LED = 2;
int YALLOW_LED = 3;
int GREEN_LED = 4; 
int sensor;
int sensorPin=A5;

void setup(){
pinMode(RED_LED,OUTPUT);
 pinMode(YALLOW_LED,OUTPUT);
 pinMode(GREEN_LED,OUTPUT);
Serial.begin(9600);

}
void loop() 
{
  {
sensor=analogRead(sensorPin);
 Serial.println(sensor); 
 delay(100);
if((sensor>100) && (sensor<400)){
  digitalWrite(RED_LED, HIGH); 
digitalWrite(YALLOW_LED, LOW); 
digitalWrite(GREEN_LED, LOW);
}
else if ((sensor>=400) && (sensor<800))
{
digitalWrite(RED_LED, LOW);
digitalWrite(YALLOW_LED, HIGH);
digitalWrite(GREEN_LED, LOW);
}
else if(sensor>-800)
{
digitalWrite(RED_LED, LOW); 
digitalWrite(YALLOW_LED, LOW);
 digitalWrite(GREEN_LED, HIGH);
}
else
{
digitalWrite(RED_LED, LOW);
 digitalWrite(YALLOW_LED, LOW); 
digitalWrite(GREEN_LED, LOW);
}
}
}