#define led 7
#define LDR 3

void setup() {
  // put your setup code here, to run once:
  pinMode(led, OUTPUT);
  pinMode(LDR, INPUT);
  Serial.begin(9600);

}

void loop() {
  // put your main code here, to run repeatedly:
  Serial.println(digitalRead(LDR));
  delay(100);

  if(digitalRead(LDR)==1){
    digitalWrite(led, HIGH);
  } else {
    digitalWrite(led, LOW);
  }

}