#define Led_red  2
#define Led_blue 26
#define Led_green 27
#define LDR 34
void setup() 
{
pinMode(Led_red, OUTPUT);
pinMode(Led_blue, OUTPUT);
pinMode(Led_green, OUTPUT);
pinMode(LDR, INPUT);
digitalWrite(Led_red, LOW);
Serial.begin(9600);
}

void loop() 
{
if(digitalRead(LDR)==HIGH) // below 100 lux
{
digitalWrite(Led_red, HIGH);
digitalWrite(Led_green, HIGH);
 }
else
{
digitalWrite(Led_red, LOW); // off
digitalWrite(Led_blue, LOW); // off
digitalWrite(Led_green, LOW); // off
}
if(digitalRead(LDR))
{
Serial.println("the led is on because there is dark");
delay(1500);
}
else
{
Serial.println("the led is off because there is light");
delay(1500);
}
}