#define Led 2
#define LDR 4

void setup() {
  pinMode(Led, OUTPUT);
  pinMode(LDR, INPUT);
  Serial.begin(9600);
}

int ldrRead, brightness;
void loop() {
  ldrRead = analogRead(LDR);
  // Serial.println(ldrRead);
  brightness = map(ldrRead, 0, 4000, 0, 100);
  Serial.println(brightness);
  analogWrite(Led, brightness);
  delay(10);
}