int luz;

#define led 9
#define ldr A0


void setup() {
  Serial.begin(9600);

pinMode(led, OUTPUT);
pinMode(ldr, INPUT);

}

void loop() {

  
  luz = analogRead(A0);
  Serial.println(luz);

  
    analogWrite(led, map(luz, 0, 1023, 0, 255));
    delay(100);

  
}