//(NO & NC) Relay Switch connected to 2LED depending on LDR sensor readings. /  case 1(Green LED) system working - case2(Red LED) system stopped
#define relay  0
#define led1 4
#define led2 16
#define LDRSENSOR2 2
int LDRvalue ;
void setup() {
   Serial.begin(9600);
pinMode(relay,OUTPUT);
pinMode(led1,OUTPUT);
pinMode(led2,OUTPUT);
pinMode(LDRSENSOR2,INPUT);
}
void loop() {
  LDRvalue = analogRead(LDRSENSOR2);

  Serial.print("Analog Value =");
Serial.println(LDRvalue);

if (LDRvalue < 2100)
{
  digitalWrite(relay,HIGH);
  digitalWrite(led2,HIGH);
   digitalWrite(led1,LOW);
   Serial.println("=> system working");
}
else{
  digitalWrite(relay,LOW);
digitalWrite(led2,LOW);
 digitalWrite(led1,HIGH);
Serial.println(" => system stoped");
}

delay(1000);
}